/*
 * Copyright (c) 2002-2018, the original author or authors.
 *
 * This software is distributable under the BSD license. See the terms of the
 * BSD license in the documentation provided with this software.
 *
 * http://www.opensource.org/licenses/bsd-license.php
 */
package jdk.internal.org.jline.reader.impl;

import java.io.Flushable;
import java.io.IOError;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.time.Instant;
import java.util.*;
import java.util.Map.Entry;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;

import jdk.internal.org.jline.keymap.BindingReader;
import jdk.internal.org.jline.keymap.KeyMap;
import jdk.internal.org.jline.reader.*;
import jdk.internal.org.jline.reader.Parser.ParseContext;
import jdk.internal.org.jline.reader.impl.history.DefaultHistory;
import jdk.internal.org.jline.terminal.*;
import jdk.internal.org.jline.terminal.Attributes.ControlChar;
import jdk.internal.org.jline.terminal.Terminal.Signal;
import jdk.internal.org.jline.terminal.Terminal.SignalHandler;
import jdk.internal.org.jline.utils.AttributedString;
import jdk.internal.org.jline.utils.AttributedStringBuilder;
import jdk.internal.org.jline.utils.AttributedStyle;
import jdk.internal.org.jline.utils.Curses;
import jdk.internal.org.jline.utils.Display;
import jdk.internal.org.jline.utils.InfoCmp.Capability;
import jdk.internal.org.jline.utils.Levenshtein;
import jdk.internal.org.jline.utils.Log;
import jdk.internal.org.jline.utils.Status;
import jdk.internal.org.jline.utils.WCWidth;

import static jdk.internal.org.jline.keymap.KeyMap.alt;
import static jdk.internal.org.jline.keymap.KeyMap.ctrl;
import static jdk.internal.org.jline.keymap.KeyMap.del;
import static jdk.internal.org.jline.keymap.KeyMap.esc;
import static jdk.internal.org.jline.keymap.KeyMap.range;
import static jdk.internal.org.jline.keymap.KeyMap.translate;

A reader for terminal applications. It supports custom tab-completion,
saveable command history, and command line editing.
Author:
Marc Prud'hommeaux, Jason Dillon, Guillaume Nodet/**
 * A reader for terminal applications. It supports custom tab-completion,
 * saveable command history, and command line editing.
 *
 * @author <a href="mailto:mwp1@cornell.edu">Marc Prud'hommeaux</a>
 * @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
 * @author <a href="mailto:gnodet@gmail.com">Guillaume Nodet</a>
 */
@SuppressWarnings("StatementWithEmptyBody")
public class LineReaderImpl implements LineReader, Flushable
{
    public static final char NULL_MASK = 0;

    public static final int TAB_WIDTH = 4;


    public static final String DEFAULT_WORDCHARS = "*?_-.[]~=/&;!#$%^(){}<>";
    public static final String DEFAULT_REMOVE_SUFFIX_CHARS = " \t\n;&|";
    public static final String DEFAULT_COMMENT_BEGIN = "#";
    public static final String DEFAULT_SEARCH_TERMINATORS = "\033\012";
    public static final String DEFAULT_BELL_STYLE = "";
    public static final int    DEFAULT_LIST_MAX = 100;
    public static final int    DEFAULT_ERRORS = 2;
    public static final long   DEFAULT_BLINK_MATCHING_PAREN = 500L;
    public static final long   DEFAULT_AMBIGUOUS_BINDING = 1000L;
    public static final String DEFAULT_SECONDARY_PROMPT_PATTERN = "%M> ";
    public static final String DEFAULT_OTHERS_GROUP_NAME = "others";
    public static final String DEFAULT_ORIGINAL_GROUP_NAME = "original";
    public static final String DEFAULT_COMPLETION_STYLE_STARTING = "36";    // cyan
    public static final String DEFAULT_COMPLETION_STYLE_DESCRIPTION = "90"; // dark gray
    public static final String DEFAULT_COMPLETION_STYLE_GROUP = "35;1";     // magenta
    public static final String DEFAULT_COMPLETION_STYLE_SELECTION = "7";    // inverted

    private static final int MIN_ROWS = 3;

    public static final String BRACKETED_PASTE_ON = "\033[?2004h";
    public static final String BRACKETED_PASTE_OFF = "\033[?2004l";
    public static final String BRACKETED_PASTE_BEGIN = "\033[200~";
    public static final String BRACKETED_PASTE_END = "\033[201~";

    public static final String FOCUS_IN_SEQ = "\033[I";
    public static final String FOCUS_OUT_SEQ = "\033[O";

    
Possible states in which the current readline operation may be in.
/**
     * Possible states in which the current readline operation may be in.
     */
    protected enum State {
        
The user is just typing away
/**
         * The user is just typing away
         */
        NORMAL,
        
readLine should exit and return the buffer content
/**
         * readLine should exit and return the buffer content
         */
        DONE,
        
readLine should exit and throw an EOFException
/**
         * readLine should exit and throw an EOFException
         */
        EOF,
        
readLine should exit and throw an UserInterruptException
/**
         * readLine should exit and throw an UserInterruptException
         */
        INTERRUPT
    }

    protected enum ViMoveMode {
        NORMAL,
        YANK,
        DELETE,
        CHANGE
    }

    protected enum BellType {
        NONE,
        AUDIBLE,
        VISIBLE
    }

    //
    // Constructor variables
    //

    
The terminal to use /** The terminal to use */
    protected final Terminal terminal;
    
The application name /** The application name */
    protected final String appName;
    
The terminal keys mapping /** The terminal keys mapping */
    protected final Map<String, KeyMap<Binding>> keyMaps;

    //
    // Configuration
    //
    protected final Map<String, Object> variables;
    protected History history = new DefaultHistory();
    protected Completer completer = null;
    protected Highlighter highlighter = new DefaultHighlighter();
    protected Parser parser = new DefaultParser();
    protected Expander expander = new DefaultExpander();

    //
    // State variables
    //

    protected final Map<Option, Boolean> options = new HashMap<>();

    protected final Buffer buf = new BufferImpl();

    protected final Size size = new Size();

    protected AttributedString prompt;
    protected AttributedString rightPrompt;

    protected MaskingCallback maskingCallback;

    protected Map<Integer, String> modifiedHistory = new HashMap<>();
    protected Buffer historyBuffer = null;
    protected CharSequence searchBuffer;
    protected StringBuffer searchTerm = null;
    protected boolean searchFailing;
    protected boolean searchBackward;
    protected int searchIndex = -1;


    // Reading buffers
    protected final BindingReader bindingReader;


    
VI character find
/**
     * VI character find
     */
    protected int findChar;
    protected int findDir;
    protected int findTailAdd;
    
VI history string search
/**
     * VI history string search
     */
    private int searchDir;
    private String searchString;

    
Region state
/**
     * Region state
     */
    protected int regionMark;
    protected RegionType regionActive;

    private boolean forceChar;
    private boolean forceLine;

    
The vi yank buffer
/**
     * The vi yank buffer
     */
    protected String yankBuffer = "";

    protected ViMoveMode viMoveMode = ViMoveMode.NORMAL;

    protected KillRing killRing = new KillRing();

    protected UndoTree<Buffer> undo = new UndoTree<>(this::setBuffer);
    protected boolean isUndo;

    /*
     * Current internal state of the line reader
     */
    protected State   state = State.DONE;
    protected final AtomicBoolean startedReading = new AtomicBoolean();
    protected boolean reading;

    protected Supplier<AttributedString> post;

    protected Map<String, Widget> builtinWidgets;
    protected Map<String, Widget> widgets;

    protected int count;
    protected int mult;
    protected int universal = 4;
    protected int repeatCount;
    protected boolean isArgDigit;

    protected ParsedLine parsedLine;

    protected boolean skipRedisplay;
    protected Display display;

    protected boolean overTyping = false;

    protected String keyMap;

    protected int smallTerminalOffset = 0;



    public LineReaderImpl(Terminal terminal) throws IOException {
        this(terminal, null, null);
    }

    public LineReaderImpl(Terminal terminal, String appName) throws IOException {
        this(terminal, appName, null);
    }

    public LineReaderImpl(Terminal terminal, String appName, Map<String, Object> variables) {
        Objects.requireNonNull(terminal, "terminal can not be null");
        this.terminal = terminal;
        if (appName == null) {
            appName = "JLine";
        }
        this.appName = appName;
        if (variables != null) {
            this.variables = variables;
        } else {
            this.variables = new HashMap<>();
        }
        this.keyMaps = defaultKeyMaps();

        builtinWidgets = builtinWidgets();
        widgets = new HashMap<>(builtinWidgets);
        bindingReader = new BindingReader(terminal.reader());
    }

    public Terminal getTerminal() {
        return terminal;
    }

    public String getAppName() {
        return appName;
    }

    public Map<String, KeyMap<Binding>> getKeyMaps() {
        return keyMaps;
    }

    public KeyMap<Binding> getKeys() {
        return keyMaps.get(keyMap);
    }

    @Override
    public Map<String, Widget> getWidgets() {
        return widgets;
    }

    @Override
    public Map<String, Widget> getBuiltinWidgets() {
        return Collections.unmodifiableMap(builtinWidgets);
    }

    @Override
    public Buffer getBuffer() {
        return buf;
    }

    @Override
    public void runMacro(String macro) {
        bindingReader.runMacro(macro);
    }

    @Override
    public MouseEvent readMouseEvent() {
        return terminal.readMouseEvent(bindingReader::readCharacter);
    }

    
Set the completer.
Params:
completer – the completer to use/**
     * Set the completer.
     *
     * @param completer the completer to use
     */
    public void setCompleter(Completer completer) {
        this.completer = completer;
    }

    
Returns the completer.
Returns:
the completer/**
     * Returns the completer.
     *
     * @return the completer
     */
    public Completer getCompleter() {
        return completer;
    }

    //
    // History
    //

    public void setHistory(final History history) {
        Objects.requireNonNull(history);
        this.history = history;
    }

    public History getHistory() {
        return history;
    }

    //
    // Highlighter
    //

    public void setHighlighter(Highlighter highlighter) {
        this.highlighter = highlighter;
    }

    public Highlighter getHighlighter() {
        return highlighter;
    }

    public Parser getParser() {
        return parser;
    }

    public void setParser(Parser parser) {
        this.parser = parser;
    }

    @Override
    public Expander getExpander() {
        return expander;
    }

    public void setExpander(Expander expander) {
        this.expander = expander;
    }

    //
    // Line Reading
    //

    
Read the next line and return the contents of the buffer.
Returns:
         A line that is read from the terminal, can never be null./**
     * Read the next line and return the contents of the buffer.
     *
     * @return          A line that is read from the terminal, can never be null.
     */
    public String readLine() throws UserInterruptException, EndOfFileException {
        return readLine(null, null, (MaskingCallback) null, null);
    }

    
Read the next line with the specified character mask. If null, then
characters will be echoed. If 0, then no characters will be echoed.
Params:
mask –      The mask character, null or 0.
Returns:
         A line that is read from the terminal, can never be null./**
     * Read the next line with the specified character mask. If null, then
     * characters will be echoed. If 0, then no characters will be echoed.
     *
     * @param mask      The mask character, <code>null</code> or <code>0</code>.
     * @return          A line that is read from the terminal, can never be null.
     */
    public String readLine(Character mask) throws UserInterruptException, EndOfFileException {
        return readLine(null, null, mask, null);
    }

    
Read a line from the in InputStream, and return the line (without any trailing newlines). 
Params:
prompt –    The prompt to issue to the terminal, may be null.
Returns:
         A line that is read from the terminal, can never be null./**
     * Read a line from the <i>in</i> {@link InputStream}, and return the line
     * (without any trailing newlines).
     *
     * @param prompt    The prompt to issue to the terminal, may be null.
     * @return          A line that is read from the terminal, can never be null.
     */
    public String readLine(String prompt) throws UserInterruptException, EndOfFileException {
        return readLine(prompt, null, (MaskingCallback) null, null);
    }

    
Read a line from the in InputStream, and return the line (without any trailing newlines). 
Params:
prompt –    The prompt to issue to the terminal, may be null.
mask –      The mask character, null or 0.
Returns:
         A line that is read from the terminal, can never be null./**
     * Read a line from the <i>in</i> {@link InputStream}, and return the line
     * (without any trailing newlines).
     *
     * @param prompt    The prompt to issue to the terminal, may be null.
     * @param mask      The mask character, <code>null</code> or <code>0</code>.
     * @return          A line that is read from the terminal, can never be null.
     */
    public String readLine(String prompt, Character mask) throws UserInterruptException, EndOfFileException {
        return readLine(prompt, null, mask, null);
    }

    
Read a line from the in InputStream, and return the line (without any trailing newlines). 
Params:
prompt –    The prompt to issue to the terminal, may be null.
mask –      The mask character, null or 0.
buffer –    A string that will be set for editing.
Returns:
         A line that is read from the terminal, can never be null./**
     * Read a line from the <i>in</i> {@link InputStream}, and return the line
     * (without any trailing newlines).
     *
     * @param prompt    The prompt to issue to the terminal, may be null.
     * @param mask      The mask character, <code>null</code> or <code>0</code>.
     * @param buffer    A string that will be set for editing.
     * @return          A line that is read from the terminal, can never be null.
     */
    public String readLine(String prompt, Character mask, String buffer) throws UserInterruptException, EndOfFileException {
        return readLine(prompt, null, mask, buffer);
    }

    
Read a line from the in InputStream, and return the line (without any trailing newlines). 
Params:
prompt –      The prompt to issue to the terminal, may be null.
rightPrompt – The prompt to issue to the right of the terminal, may be null.
mask –        The mask character, null or 0.
buffer –      A string that will be set for editing.
Returns:
           A line that is read from the terminal, can never be null./**
     * Read a line from the <i>in</i> {@link InputStream}, and return the line
     * (without any trailing newlines).
     *
     * @param prompt      The prompt to issue to the terminal, may be null.
     * @param rightPrompt The prompt to issue to the right of the terminal, may be null.
     * @param mask        The mask character, <code>null</code> or <code>0</code>.
     * @param buffer      A string that will be set for editing.
     * @return            A line that is read from the terminal, can never be null.
     */
    public String readLine(String prompt, String rightPrompt, Character mask, String buffer) throws UserInterruptException, EndOfFileException {
        return readLine(prompt, rightPrompt, mask != null ? new SimpleMaskingCallback(mask) : null, buffer);
    }

    
Read a line from the in InputStream, and return the line (without any trailing newlines). 
Params:
prompt –          The prompt to issue to the terminal, may be null.
rightPrompt –     The prompt to issue to the right of the terminal, may be null.
maskingCallback – The callback used to mask parts of the edited line.
buffer –          A string that will be set for editing.
Returns:
               A line that is read from the terminal, can never be null./**
     * Read a line from the <i>in</i> {@link InputStream}, and return the line
     * (without any trailing newlines).
     *
     * @param prompt          The prompt to issue to the terminal, may be null.
     * @param rightPrompt     The prompt to issue to the right of the terminal, may be null.
     * @param maskingCallback The callback used to mask parts of the edited line.
     * @param buffer          A string that will be set for editing.
     * @return                A line that is read from the terminal, can never be null.
     */
    public String readLine(String prompt, String rightPrompt, MaskingCallback maskingCallback, String buffer) throws UserInterruptException, EndOfFileException {
        // prompt may be null
        // maskingCallback may be null
        // buffer may be null

        if (!startedReading.compareAndSet(false, true)) {
            throw new IllegalStateException();
        }

        Thread readLineThread = Thread.currentThread();
        SignalHandler previousIntrHandler = null;
        SignalHandler previousWinchHandler = null;
        SignalHandler previousContHandler = null;
        Attributes originalAttributes = null;
        boolean dumb = Terminal.TYPE_DUMB.equals(terminal.getType())
                    || Terminal.TYPE_DUMB_COLOR.equals(terminal.getType());
        try {

            this.maskingCallback = maskingCallback;

            /*
             * This is the accumulator for VI-mode repeat count. That is, while in
             * move mode, if you type 30x it will delete 30 characters. This is
             * where the "30" is accumulated until the command is struck.
             */
            repeatCount = 0;
            mult = 1;
            regionActive = RegionType.NONE;
            regionMark = -1;

            smallTerminalOffset = 0;

            state = State.NORMAL;

            modifiedHistory.clear();

            setPrompt(prompt);
            setRightPrompt(rightPrompt);
            buf.clear();
            if (buffer != null) {
                buf.write(buffer);
            }
            undo.clear();
            parsedLine = null;
            keyMap = MAIN;

            if (history != null) {
                history.attach(this);
            }

            synchronized (this) {
                this.reading = true;

                previousIntrHandler = terminal.handle(Signal.INT, signal -> readLineThread.interrupt());
                previousWinchHandler = terminal.handle(Signal.WINCH, this::handleSignal);
                previousContHandler = terminal.handle(Signal.CONT, this::handleSignal);
                originalAttributes = terminal.enterRawMode();

                // Cache terminal size for the duration of the call to readLine()
                // It will eventually be updated with WINCH signals
                size.copy(terminal.getSize());

                display = new Display(terminal, false);
                if (size.getRows() == 0 || size.getColumns() == 0) {
                    display.resize(1, Integer.MAX_VALUE);
                } else {
                    display.resize(size.getRows(), size.getColumns());
                }
                if (isSet(Option.DELAY_LINE_WRAP))
                    display.setDelayLineWrap(true);

                // Move into application mode
                if (!dumb) {
                    terminal.puts(Capability.keypad_xmit);
                    if (isSet(Option.AUTO_FRESH_LINE))
                        callWidget(FRESH_LINE);
                    if (isSet(Option.MOUSE))
                        terminal.trackMouse(Terminal.MouseTracking.Normal);
                    if (isSet(Option.BRACKETED_PASTE))
                        terminal.writer().write(BRACKETED_PASTE_ON);
                } else {
                    // For dumb terminals, we need to make sure that CR are ignored
                    Attributes attr = new Attributes(originalAttributes);
                    attr.setInputFlag(Attributes.InputFlag.IGNCR, true);
                    terminal.setAttributes(attr);
                }

                callWidget(CALLBACK_INIT);

                undo.newState(buf.copy());

                // Draw initial prompt
                redrawLine();
                redisplay();
            }

            while (true) {

                KeyMap<Binding> local = null;
                if (isInViCmdMode() && regionActive != RegionType.NONE) {
                    local = keyMaps.get(VISUAL);
                }
                Binding o = readBinding(getKeys(), local);
                if (o == null) {
                    throw new EndOfFileException();
                }
                Log.trace("Binding: ", o);
                if (buf.length() == 0 && getLastBinding().charAt(0) == originalAttributes.getControlChar(ControlChar.VEOF)) {
                    throw new EndOfFileException();
                }

                // If this is still false after handling the binding, then
                // we reset our repeatCount to 0.
                isArgDigit = false;
                // Every command that can be repeated a specified number
                // of times, needs to know how many times to repeat, so
                // we figure that out here.
                count = ((repeatCount == 0) ? 1 : repeatCount) * mult;
                // Reset undo/redo flag
                isUndo = false;
                // Reset region after a paste
                if (regionActive == RegionType.PASTE) {
                    regionActive = RegionType.NONE;
                }

                synchronized (this) {
                    // Get executable widget
                    Buffer copy = buf.copy();
                    Widget w = getWidget(o);
                    if (!w.apply()) {
                        beep();
                    }
                    if (!isUndo && !copy.toString().equals(buf.toString())) {
                        undo.newState(buf.copy());
                    }

                    switch (state) {
                        case DONE:
                            return finishBuffer();
                        case EOF:
                            throw new EndOfFileException();
                        case INTERRUPT:
                            throw new UserInterruptException(buf.toString());
                    }

                    if (!isArgDigit) {
                        /*
                         * If the operation performed wasn't a vi argument
                         * digit, then clear out the current repeatCount;
                         */
                        repeatCount = 0;
                        mult = 1;
                    }

                    if (!dumb) {
                        redisplay();
                    }
                }
            }
        } catch (IOError e) {
            if (e.getCause() instanceof InterruptedIOException) {
                throw new UserInterruptException(buf.toString());
            } else {
                throw e;
            }
        }
        finally {
            synchronized (this) {
                this.reading = false;

                cleanup();
                if (originalAttributes != null) {
                    terminal.setAttributes(originalAttributes);
                }
                if (previousIntrHandler != null) {
                    terminal.handle(Signal.INT, previousIntrHandler);
                }
                if (previousWinchHandler != null) {
                    terminal.handle(Signal.WINCH, previousWinchHandler);
                }
                if (previousContHandler != null) {
                    terminal.handle(Signal.CONT, previousContHandler);
                }
            }
            startedReading.set(false);
        }
    }

    @Override
    public synchronized void printAbove(String str) {
        boolean reading = this.reading;
        if (reading) {
            display.update(Collections.emptyList(), 0);
        }
        if (str.endsWith("\n")) {
            terminal.writer().print(str);
        } else {
            terminal.writer().println(str);
        }
        if (reading) {
            redisplay(false);
        }
        terminal.flush();
    }

    @Override
    public void printAbove(AttributedString str) {
        printAbove(str.toAnsi(terminal));
    }

    @Override
    public synchronized boolean isReading() {
        return reading;
    }

    /* Make sure we position the cursor on column 0 */
    protected boolean freshLine() {
        boolean wrapAtEol = terminal.getBooleanCapability(Capability.auto_right_margin);
        boolean delayedWrapAtEol = wrapAtEol && terminal.getBooleanCapability(Capability.eat_newline_glitch);
        AttributedStringBuilder sb = new AttributedStringBuilder();
        sb.style(AttributedStyle.DEFAULT.foreground(AttributedStyle.BLACK + AttributedStyle.BRIGHT));
        sb.append("~");
        sb.style(AttributedStyle.DEFAULT);
        if (!wrapAtEol || delayedWrapAtEol) {
            for (int i = 0; i < size.getColumns() - 1; i++) {
                sb.append(" ");
            }
            sb.append(KeyMap.key(terminal, Capability.carriage_return));
            sb.append(" ");
            sb.append(KeyMap.key(terminal, Capability.carriage_return));
        } else {
            // Given the terminal will wrap automatically,
            // we need to print one less than needed.
            // This means that the last character will not
            // be overwritten, and that's why we're using
            // a clr_eol first if possible.
            String el = terminal.getStringCapability(Capability.clr_eol);
            if (el != null) {
                Curses.tputs(sb, el);
            }
            for (int i = 0; i < size.getColumns() - 2; i++) {
                sb.append(" ");
            }
            sb.append(KeyMap.key(terminal, Capability.carriage_return));
            sb.append(" ");
            sb.append(KeyMap.key(terminal, Capability.carriage_return));
        }
        print(sb.toAnsi(terminal));
        return true;
    }

    @Override
    public synchronized void callWidget(String name) {
        if (!reading) {
            throw new IllegalStateException("Widgets can only be called during a `readLine` call");
        }
        try {
            Widget w;
            if (name.startsWith(".")) {
                w = builtinWidgets.get(name.substring(1));
            } else {
                w = widgets.get(name);
            }
            if (w != null) {
                w.apply();
            }
        } catch (Throwable t) {
            Log.debug("Error executing widget '", name, "'", t);
        }
    }

    
Clear the line and redraw it.
Returns:
true/**
     * Clear the line and redraw it.
     * @return <code>true</code>
     */
    public boolean redrawLine() {
        display.reset();
        return true;
    }

    
Write out the specified string to the buffer and the output stream.
Params:
str – the char sequence to write in the buffer/**
     * Write out the specified string to the buffer and the output stream.
     * @param str the char sequence to write in the buffer
     */
    public void putString(final CharSequence str) {
        buf.write(str, overTyping);
    }

    
Flush the terminal output stream. This is important for printout out single
characters (like a buf.backspace or keyboard) that we want the terminal to
handle immediately.
/**
     * Flush the terminal output stream. This is important for printout out single
     * characters (like a buf.backspace or keyboard) that we want the terminal to
     * handle immediately.
     */
    public void flush() {
        terminal.flush();
    }

    public boolean isKeyMap(String name) {
        return keyMap.equals(name);
    }

    
Read a character from the terminal.
Returns:
the character, or -1 if an EOF is received./**
     * Read a character from the terminal.
     *
     * @return the character, or -1 if an EOF is received.
     */
    public int readCharacter() {
        return bindingReader.readCharacter();
    }

    public int peekCharacter(long timeout) {
        return bindingReader.peekCharacter(timeout);
    }

    
Read from the input stream and decode an operation from the key map.
The input stream will be read character by character until a matching
binding can be found.  Characters that can't possibly be matched to
any binding will be discarded.
Params:
keys – the KeyMap to use for decoding the input stream
Returns:
the decoded binding or null if the end of
        stream has been reached/**
     * Read from the input stream and decode an operation from the key map.
     *
     * The input stream will be read character by character until a matching
     * binding can be found.  Characters that can't possibly be matched to
     * any binding will be discarded.
     *
     * @param keys the KeyMap to use for decoding the input stream
     * @return the decoded binding or <code>null</code> if the end of
     *         stream has been reached
     */
    public Binding readBinding(KeyMap<Binding> keys) {
        return readBinding(keys, null);
    }

    public Binding readBinding(KeyMap<Binding> keys, KeyMap<Binding> local) {
        Binding o = bindingReader.readBinding(keys, local);
        /*
         * The kill ring keeps record of whether or not the
         * previous command was a yank or a kill. We reset
         * that state here if needed.
         */
        if (o instanceof Reference) {
            String ref = ((Reference) o).name();
            if (!YANK_POP.equals(ref) && !YANK.equals(ref)) {
                killRing.resetLastYank();
            }
            if (!KILL_LINE.equals(ref) && !KILL_WHOLE_LINE.equals(ref)
                    && !BACKWARD_KILL_WORD.equals(ref) && !KILL_WORD.equals(ref)) {
                killRing.resetLastKill();
            }
        }
        return o;
    }

    @Override
    public ParsedLine getParsedLine() {
        return parsedLine;
    }

    public String getLastBinding() {
        return bindingReader.getLastBinding();
    }

    public String getSearchTerm() {
        return searchTerm != null ? searchTerm.toString() : null;
    }

    @Override
    public RegionType getRegionActive() {
        return regionActive;
    }

    @Override
    public int getRegionMark() {
        return regionMark;
    }

    //
    // Key Bindings
    //

    
Sets the current keymap by name. Supported keymaps are "emacs",
"viins", "vicmd".
Params:
name – The name of the keymap to switch to
Returns:
true if the keymap was set, or false if the keymap is
   not recognized./**
     * Sets the current keymap by name. Supported keymaps are "emacs",
     * "viins", "vicmd".
     * @param name The name of the keymap to switch to
     * @return true if the keymap was set, or false if the keymap is
     *    not recognized.
     */
    public boolean setKeyMap(String name) {
        KeyMap<Binding> map = keyMaps.get(name);
        if (map == null) {
            return false;
        }
        this.keyMap = name;
        if (reading) {
            callWidget(CALLBACK_KEYMAP);
        }
        return true;
    }

    
Returns the name of the current key mapping.
Returns:
the name of the key mapping. This will be the canonical name of the current mode of the key map and may not reflect the name that was used with setKeyMap(String)./**
     * Returns the name of the current key mapping.
     * @return the name of the key mapping. This will be the canonical name
     *   of the current mode of the key map and may not reflect the name that
     *   was used with {@link #setKeyMap(String)}.
     */
    public String getKeyMap() {
        return keyMap;
    }

    @Override
    public LineReader variable(String name, Object value) {
        variables.put(name, value);
        return this;
    }

    @Override
    public Map<String, Object> getVariables() {
        return variables;
    }

    @Override
    public Object getVariable(String name) {
        return variables.get(name);
    }

    @Override
    public void setVariable(String name, Object value) {
        variables.put(name, value);
    }

    @Override
    public LineReader option(Option option, boolean value) {
        options.put(option, value);
        return this;
    }

    @Override
    public boolean isSet(Option option) {
        Boolean b = options.get(option);
        return b != null ? b : option.isDef();
    }

    @Override
    public void setOpt(Option option) {
        options.put(option, Boolean.TRUE);
    }

    @Override
    public void unsetOpt(Option option) {
        options.put(option, Boolean.FALSE);
    }



    //
    // Widget implementation
    //

    
Clear the buffer and add its contents to the history.
Returns:
the former contents of the buffer./**
     * Clear the buffer and add its contents to the history.
     *
     * @return the former contents of the buffer.
     */
    protected String finishBuffer() {
        String str = buf.toString();
        String historyLine = str;

        if (!isSet(Option.DISABLE_EVENT_EXPANSION)) {
            StringBuilder sb = new StringBuilder();
            boolean escaped = false;
            for (int i = 0; i < str.length(); i++) {
                char ch = str.charAt(i);
                if (escaped) {
                    escaped = false;
                    if (ch != '\n') {
                        sb.append(ch);
                    }
                } else if (ch == '\\') {
                    escaped = true;
                } else {
                    sb.append(ch);
                }
            }
            str = sb.toString();
        }

        if (maskingCallback != null) {
            historyLine = maskingCallback.history(historyLine);
        }

        // we only add it to the history if the buffer is not empty
        if (historyLine != null && historyLine.length() > 0 ) {
            history.add(Instant.now(), historyLine);
        }
        return str;
    }

    protected void handleSignal(Signal signal) {
        if (signal == Signal.WINCH) {
            size.copy(terminal.getSize());
            display.resize(size.getRows(), size.getColumns());
            redisplay();
        }
        else if (signal == Signal.CONT) {
            terminal.enterRawMode();
            size.copy(terminal.getSize());
            display.resize(size.getRows(), size.getColumns());
            terminal.puts(Capability.keypad_xmit);
            redrawLine();
            redisplay();
        }
    }

    @SuppressWarnings("unchecked")
    protected Widget getWidget(Object binding) {
        Widget w;
        if (binding instanceof Widget) {
            w = (Widget) binding;
        } else if (binding instanceof Macro) {
            String macro = ((Macro) binding).getSequence();
            w = () -> {
                bindingReader.runMacro(macro);
                return true;
            };
        } else if (binding instanceof Reference) {
            String name = ((Reference) binding).name();
            w = widgets.get(name);
            if (w == null) {
                w = () -> {
                    post = () -> new AttributedString("No such widget `" + name + "'");
                    return false;
                };
            }
        } else {
            w = () -> {
                post = () -> new AttributedString("Unsupported widget");
                return false;
            };
        }
        return w;
    }

    //
    // Helper methods
    //

    public void setPrompt(final String prompt) {
        this.prompt = (prompt == null ? AttributedString.EMPTY
                       : expandPromptPattern(prompt, 0, "", 0));
    }

    public void setRightPrompt(final String rightPrompt) {
        this.rightPrompt = (rightPrompt == null ? AttributedString.EMPTY
                            : expandPromptPattern(rightPrompt, 0, "", 0));
    }

    protected void setBuffer(Buffer buffer) {
        buf.copyFrom(buffer);
    }

    
Set the current buffer's content to the specified String. The visual terminal will be modified to show the current buffer. 
Params:
buffer – the new contents of the buffer./**
     * Set the current buffer's content to the specified {@link String}. The
     * visual terminal will be modified to show the current buffer.
     *
     * @param buffer the new contents of the buffer.
     */
    protected void setBuffer(final String buffer) {
        buf.clear();
        buf.write(buffer);
    }

    
This method is calling while doing a delete-to ("d"), change-to ("c"),
or yank-to ("y") and it filters out only those movement operations
that are allowable during those operations. Any operation that isn't
allow drops you back into movement mode.
Params:
op – The incoming operation to remap
Returns:
The remaped operation/**
     * This method is calling while doing a delete-to ("d"), change-to ("c"),
     * or yank-to ("y") and it filters out only those movement operations
     * that are allowable during those operations. Any operation that isn't
     * allow drops you back into movement mode.
     *
     * @param op The incoming operation to remap
     * @return The remaped operation
     */
    protected String viDeleteChangeYankToRemap (String op) {
        switch (op) {
            case SEND_BREAK:
            case BACKWARD_CHAR:
            case FORWARD_CHAR:
            case END_OF_LINE:
            case VI_MATCH_BRACKET:
            case VI_DIGIT_OR_BEGINNING_OF_LINE:
            case NEG_ARGUMENT:
            case DIGIT_ARGUMENT:
            case VI_BACKWARD_CHAR:
            case VI_BACKWARD_WORD:
            case VI_FORWARD_CHAR:
            case VI_FORWARD_WORD:
            case VI_FORWARD_WORD_END:
            case VI_FIRST_NON_BLANK:
            case VI_GOTO_COLUMN:
            case VI_DELETE:
            case VI_YANK:
            case VI_CHANGE:
            case VI_FIND_NEXT_CHAR:
            case VI_FIND_NEXT_CHAR_SKIP:
            case VI_FIND_PREV_CHAR:
            case VI_FIND_PREV_CHAR_SKIP:
            case VI_REPEAT_FIND:
            case VI_REV_REPEAT_FIND:
                return op;

            default:
                return VI_CMD_MODE;
        }
    }

    protected int switchCase(int ch) {
        if (Character.isUpperCase(ch)) {
            return Character.toLowerCase(ch);
        } else if (Character.isLowerCase(ch)) {
            return Character.toUpperCase(ch);
        } else {
            return ch;
        }
    }

    
Returns:
true if line reader is in the middle of doing a change-to
  delete-to or yank-to./**
     * @return true if line reader is in the middle of doing a change-to
     *   delete-to or yank-to.
     */
    protected boolean isInViMoveOperation() {
        return viMoveMode != ViMoveMode.NORMAL;
    }

    protected boolean isInViChangeOperation() {
        return viMoveMode == ViMoveMode.CHANGE;
    }

    protected boolean isInViCmdMode() {
        return VICMD.equals(keyMap);
    }


    //
    // Movement
    //

    protected boolean viForwardChar() {
        if (count < 0) {
            return callNeg(this::viBackwardChar);
        }
        int lim = findeol();
        if (isInViCmdMode() && !isInViMoveOperation()) {
            lim--;
        }
        if (buf.cursor() >= lim) {
            return false;
        }
        while (count-- > 0 && buf.cursor() < lim) {
            buf.move(1);
        }
        return true;
    }

    protected boolean viBackwardChar() {
        if (count < 0) {
            return callNeg(this::viForwardChar);
        }
        int lim = findbol();
        if (buf.cursor() == lim) {
            return false;
        }
        while (count-- > 0 && buf.cursor() > 0) {
            buf.move(-1);
            if (buf.currChar() == '\n') {
                buf.move(1);
                break;
            }
        }
        return true;
    }


    //
    // Word movement
    //

    protected boolean forwardWord() {
        if (count < 0) {
            return callNeg(this::backwardWord);
        }
        while (count-- > 0) {
            while (buf.cursor() < buf.length() && isWord(buf.currChar())) {
                buf.move(1);
            }
            if (isInViChangeOperation() && count == 0) {
                break;
            }
            while (buf.cursor() < buf.length() && !isWord(buf.currChar())) {
                buf.move(1);
            }
        }
        return true;
    }

    protected boolean viForwardWord() {
        if (count < 0) {
            return callNeg(this::backwardWord);
        }
        while (count-- > 0) {
            if (isViAlphaNum(buf.currChar())) {
                while (buf.cursor() < buf.length() && isViAlphaNum(buf.currChar())) {
                    buf.move(1);
                }
            } else {
                while (buf.cursor() < buf.length()
                        && !isViAlphaNum(buf.currChar())
                        && !isWhitespace(buf.currChar())) {
                    buf.move(1);
                }
            }
            if (isInViChangeOperation() && count == 0) {
                return true;
            }
            int nl = buf.currChar() == '\n' ? 1 : 0;
            while (buf.cursor() < buf.length()
                    && nl < 2
                    && isWhitespace(buf.currChar())) {
                buf.move(1);
                nl += buf.currChar() == '\n' ? 1 : 0;
            }
        }
        return true;
    }

    protected boolean viForwardBlankWord() {
        if (count < 0) {
            return callNeg(this::viBackwardBlankWord);
        }
        while (count-- > 0) {
            while (buf.cursor() < buf.length() && !isWhitespace(buf.currChar())) {
                buf.move(1);
            }
            if (isInViChangeOperation() && count == 0) {
                return true;
            }
            int nl = buf.currChar() == '\n' ? 1 : 0;
            while (buf.cursor() < buf.length()
                    && nl < 2
                    && isWhitespace(buf.currChar())) {
                buf.move(1);
                nl += buf.currChar() == '\n' ? 1 : 0;
            }
        }
        return true;
    }

    protected boolean emacsForwardWord() {
        if (count < 0) {
            return callNeg(this::emacsBackwardWord);
        }
        while (count-- > 0) {
            while (buf.cursor() < buf.length() && !isWord(buf.currChar())) {
                buf.move(1);
            }
            if (isInViChangeOperation() && count == 0) {
                return true;
            }
            while (buf.cursor() < buf.length() && isWord(buf.currChar())) {
                buf.move(1);
            }
        }
        return true;
    }

    protected boolean viForwardBlankWordEnd() {
        if (count < 0) {
            return false;
        }
        while (count-- > 0) {
            while (buf.cursor() < buf.length()) {
                buf.move(1);
                if (!isWhitespace(buf.currChar())) {
                    break;
                }
            }
            while (buf.cursor() < buf.length()) {
                buf.move(1);
                if (isWhitespace(buf.currChar())) {
                    break;
                }
            }
        }
        return true;
    }

    protected boolean viForwardWordEnd() {
        if (count < 0) {
            return callNeg(this::backwardWord);
        }
        while (count-- > 0) {
            while (buf.cursor() < buf.length()) {
                if (!isWhitespace(buf.nextChar())) {
                    break;
                }
                buf.move(1);
            }
            if (buf.cursor() < buf.length()) {
                if (isViAlphaNum(buf.nextChar())) {
                    buf.move(1);
                    while (buf.cursor() < buf.length() && isViAlphaNum(buf.nextChar())) {
                        buf.move(1);
                    }
                } else {
                    buf.move(1);
                    while (buf.cursor() < buf.length() && !isViAlphaNum(buf.nextChar()) && !isWhitespace(buf.nextChar())) {
                        buf.move(1);
                    }
                }
            }
        }
        if (buf.cursor() < buf.length() && isInViMoveOperation()) {
            buf.move(1);
        }
        return true;
    }

    protected boolean backwardWord() {
        if (count < 0) {
            return callNeg(this::forwardWord);
        }
        while (count-- > 0) {
            while (buf.cursor() > 0 && !isWord(buf.atChar(buf.cursor() - 1))) {
                buf.move(-1);
            }
            while (buf.cursor() > 0 && isWord(buf.atChar(buf.cursor() - 1))) {
                buf.move(-1);
            }
        }
        return true;
    }

    protected boolean viBackwardWord() {
        if (count < 0) {
            return callNeg(this::backwardWord);
        }
        while (count-- > 0) {
            int nl = 0;
            while (buf.cursor() > 0) {
                buf.move(-1);
                if (!isWhitespace(buf.currChar())) {
                    break;
                }
                nl += buf.currChar() == '\n' ? 1 : 0;
                if (nl == 2) {
                    buf.move(1);
                    break;
                }
            }
            if (buf.cursor() > 0) {
                if (isViAlphaNum(buf.currChar())) {
                    while (buf.cursor() > 0) {
                        if (!isViAlphaNum(buf.prevChar())) {
                            break;
                        }
                        buf.move(-1);
                    }
                } else {
                    while (buf.cursor() > 0) {
                        if (isViAlphaNum(buf.prevChar()) || isWhitespace(buf.prevChar())) {
                            break;
                        }
                        buf.move(-1);
                    }
                }
            }
        }
        return true;
    }

    protected boolean viBackwardBlankWord() {
        if (count < 0) {
            return callNeg(this::viForwardBlankWord);
        }
        while (count-- > 0) {
            while (buf.cursor() > 0) {
                buf.move(-1);
                if (!isWhitespace(buf.currChar())) {
                    break;
                }
            }
            while (buf.cursor() > 0) {
                buf.move(-1);
                if (isWhitespace(buf.currChar())) {
                    break;
                }
            }
        }
        return true;
    }

    protected boolean viBackwardWordEnd() {
        if (count < 0) {
            return callNeg(this::viForwardWordEnd);
        }
        while (count-- > 0 && buf.cursor() > 1) {
            int start;
            if (isViAlphaNum(buf.currChar())) {
                start = 1;
            } else if (!isWhitespace(buf.currChar())) {
                start = 2;
            } else {
                start = 0;
            }
            while (buf.cursor() > 0) {
                boolean same = (start != 1) && isWhitespace(buf.currChar());
                if (start != 0) {
                    same |= isViAlphaNum(buf.currChar());
                }
                if (same == (start == 2)) {
                    break;
                }
                buf.move(-1);
            }
            while (buf.cursor() > 0 && isWhitespace(buf.currChar())) {
                buf.move(-1);
            }
        }
        return true;
    }

    protected boolean viBackwardBlankWordEnd() {
        if (count < 0) {
            return callNeg(this::viForwardBlankWordEnd);
        }
        while (count-- > 0) {
            while (buf.cursor() > 0 && !isWhitespace(buf.currChar())) {
                buf.move(-1);
            }
            while (buf.cursor() > 0 && isWhitespace(buf.currChar())) {
                buf.move(-1);
            }
        }
        return true;
    }

    protected boolean emacsBackwardWord() {
        if (count < 0) {
            return callNeg(this::emacsForwardWord);
        }
        while (count-- > 0) {
            while (buf.cursor() > 0) {
                buf.move(-1);
                if (isWord(buf.currChar())) {
                    break;
                }
            }
            while (buf.cursor() > 0) {
                buf.move(-1);
                if (!isWord(buf.currChar())) {
                    break;
                }
            }
        }
        return true;
    }

    protected boolean backwardDeleteWord() {
        if (count < 0) {
            return callNeg(this::deleteWord);
        }
        int cursor = buf.cursor();
        while (count-- > 0) {
            while (cursor > 0 && !isWord(buf.atChar(cursor - 1))) {
                cursor--;
            }
            while (cursor > 0 && isWord(buf.atChar(cursor - 1))) {
                cursor--;
            }
        }
        buf.backspace(buf.cursor() - cursor);
        return true;
    }

    protected boolean viBackwardKillWord() {
        if (count < 0) {
            return false;
        }
        int lim = findbol();
        int x = buf.cursor();
        while (count-- > 0) {
            while (x > lim && isWhitespace(buf.atChar(x - 1))) {
                x--;
            }
            if (x > lim) {
                if (isViAlphaNum(buf.atChar(x - 1))) {
                    while (x > lim && isViAlphaNum(buf.atChar(x - 1))) {
                        x--;
                    }
                } else {
                    while (x > lim && !isViAlphaNum(buf.atChar(x - 1)) && !isWhitespace(buf.atChar(x - 1))) {
                        x--;
                    }
                }
            }
        }
        killRing.addBackwards(buf.substring(x, buf.cursor()));
        buf.backspace(buf.cursor() - x);
        return true;
    }

    protected boolean backwardKillWord() {
        if (count < 0) {
            return callNeg(this::killWord);
        }
        int x = buf.cursor();
        while (count-- > 0) {
            while (x > 0 && !isWord(buf.atChar(x - 1))) {
                x--;
            }
            while (x > 0 && isWord(buf.atChar(x - 1))) {
                x--;
            }
        }
        killRing.addBackwards(buf.substring(x, buf.cursor()));
        buf.backspace(buf.cursor() - x);
        return true;
    }

    protected boolean copyPrevWord() {
        if (count <= 0) {
            return false;
        }
        int t1, t0 = buf.cursor();
        while (true) {
            t1 = t0;
            while (t0 > 0 && !isWord(buf.atChar(t0 - 1))) {
                t0--;
            }
            while (t0 > 0 && isWord(buf.atChar(t0 - 1))) {
                t0--;
            }
            if (--count == 0) {
                break;
            }
            if (t0 == 0) {
                return false;
            }
        }
        buf.write(buf.substring(t0, t1));
        return true;
    }

    protected boolean upCaseWord() {
        int count = Math.abs(this.count);
        int cursor = buf.cursor();
        while (count-- > 0) {
            while (buf.cursor() < buf.length() && !isWord(buf.currChar())) {
                buf.move(1);
            }
            while (buf.cursor() < buf.length() && isWord(buf.currChar())) {
                buf.currChar(Character.toUpperCase(buf.currChar()));
                buf.move(1);
            }
        }
        if (this.count < 0) {
            buf.cursor(cursor);
        }
        return true;
    }

    protected boolean downCaseWord() {
        int count = Math.abs(this.count);
        int cursor = buf.cursor();
        while (count-- > 0) {
            while (buf.cursor() < buf.length() && !isWord(buf.currChar())) {
                buf.move(1);
            }
            while (buf.cursor() < buf.length() && isWord(buf.currChar())) {
                buf.currChar(Character.toLowerCase(buf.currChar()));
                buf.move(1);
            }
        }
        if (this.count < 0) {
            buf.cursor(cursor);
        }
        return true;
    }

    protected boolean capitalizeWord() {
        int count = Math.abs(this.count);
        int cursor = buf.cursor();
        while (count-- > 0) {
            boolean first = true;
            while (buf.cursor() < buf.length() && !isWord(buf.currChar())) {
                buf.move(1);
            }
            while (buf.cursor() < buf.length() && isWord(buf.currChar()) && !isAlpha(buf.currChar())) {
                buf.move(1);
            }
            while (buf.cursor() < buf.length() && isWord(buf.currChar())) {
                buf.currChar(first
                        ? Character.toUpperCase(buf.currChar())
                        : Character.toLowerCase(buf.currChar()));
                buf.move(1);
                first = false;
            }
        }
        if (this.count < 0) {
            buf.cursor(cursor);
        }
        return true;
    }

    protected boolean deleteWord() {
        if (count < 0) {
            return callNeg(this::backwardDeleteWord);
        }
        int x = buf.cursor();
        while (count-- > 0) {
            while (x < buf.length() && !isWord(buf.atChar(x))) {
                x++;
            }
            while (x < buf.length() && isWord(buf.atChar(x))) {
                x++;
            }
        }
        buf.delete(x - buf.cursor());
        return true;
    }

    protected boolean killWord() {
        if (count < 0) {
            return callNeg(this::backwardKillWord);
        }
        int x = buf.cursor();
        while (count-- > 0) {
            while (x < buf.length() && !isWord(buf.atChar(x))) {
                x++;
            }
            while (x < buf.length() && isWord(buf.atChar(x))) {
                x++;
            }
        }
        killRing.add(buf.substring(buf.cursor(), x));
        buf.delete(x - buf.cursor());
        return true;
    }

    protected boolean transposeWords() {
        int lstart = buf.cursor() - 1;
        int lend = buf.cursor();
        while (buf.atChar(lstart) != 0 && buf.atChar(lstart) != '\n') {
            lstart--;
        }
        lstart++;
        while (buf.atChar(lend) != 0 && buf.atChar(lend) != '\n') {
            lend++;
        }
        if (lend - lstart < 2) {
            return false;
        }
        int words = 0;
        boolean inWord = false;
        if (!isDelimiter(buf.atChar(lstart))) {
            words++;
            inWord = true;
        }
        for (int i = lstart; i < lend; i++) {
            if (isDelimiter(buf.atChar(i))) {
                inWord = false;
            } else {
                if (!inWord) {
                    words++;
                }
                inWord = true;
            }
        }
        if (words < 2) {
            return false;
        }
        // TODO: use isWord instead of isDelimiter
        boolean neg = this.count < 0;
        for (int count = Math.max(this.count, -this.count); count > 0; --count) {
            int sta1, end1, sta2, end2;
            // Compute current word boundaries
            sta1 = buf.cursor();
            while (sta1 > lstart && !isDelimiter(buf.atChar(sta1 - 1))) {
                sta1--;
            }
            end1 = sta1;
            while (end1 < lend && !isDelimiter(buf.atChar(++end1)));
            if (neg) {
                end2 = sta1 - 1;
                while (end2 > lstart && isDelimiter(buf.atChar(end2 - 1))) {
                    end2--;
                }
                if (end2 < lstart) {
                    // No word before, use the word after
                    sta2 = end1;
                    while (isDelimiter(buf.atChar(++sta2)));
                    end2 = sta2;
                    while (end2 < lend && !isDelimiter(buf.atChar(++end2)));
                } else {
                    sta2 = end2;
                    while (sta2 > lstart && !isDelimiter(buf.atChar(sta2 - 1))) {
                        sta2--;
                    }
                }
            } else {
                sta2 = end1;
                while (sta2 < lend && isDelimiter(buf.atChar(++sta2)));
                if (sta2 == lend) {
                    // No word after, use the word before
                    end2 = sta1;
                    while (isDelimiter(buf.atChar(end2 - 1))) {
                        end2--;
                    }
                    sta2 = end2;
                    while (sta2 > lstart && !isDelimiter(buf.atChar(sta2 - 1))) {
                        sta2--;
                    }
                } else {
                    end2 = sta2;
                    while (end2 < lend && !isDelimiter(buf.atChar(++end2))) ;
                }
            }
            if (sta1 < sta2) {
                String res = buf.substring(0, sta1) + buf.substring(sta2, end2)
                        + buf.substring(end1, sta2) + buf.substring(sta1, end1)
                        + buf.substring(end2);
                buf.clear();
                buf.write(res);
                buf.cursor(neg ? end1 : end2);
            } else {
                String res = buf.substring(0, sta2) + buf.substring(sta1, end1)
                        + buf.substring(end2, sta1) + buf.substring(sta2, end2)
                        + buf.substring(end1);
                buf.clear();
                buf.write(res);
                buf.cursor(neg ? end2 : end1);
            }
        }
        return true;
    }

    private int findbol() {
        int x = buf.cursor();
        while (x > 0 && buf.atChar(x - 1) != '\n') {
            x--;
        }
        return x;
    }

    private int findeol() {
        int x = buf.cursor();
        while (x < buf.length() && buf.atChar(x) != '\n') {
            x++;
        }
        return x;
    }

    protected boolean insertComment() {
        return doInsertComment(false);
    }

    protected boolean viInsertComment() {
        return doInsertComment(true);
    }

    protected boolean doInsertComment(boolean isViMode) {
        String comment = getString(COMMENT_BEGIN, DEFAULT_COMMENT_BEGIN);
        beginningOfLine();
        putString(comment);
        if (isViMode) {
            setKeyMap(VIINS);
        }
        return acceptLine();
    }

    protected boolean viFindNextChar() {
        if ((findChar = vigetkey()) > 0) {
            findDir = 1;
            findTailAdd = 0;
            return vifindchar(false);
        }
        return false;
    }

    protected boolean viFindPrevChar() {
        if ((findChar = vigetkey()) > 0) {
            findDir = -1;
            findTailAdd = 0;
            return vifindchar(false);
        }
        return false;
    }

    protected boolean viFindNextCharSkip() {
        if ((findChar = vigetkey()) > 0) {
            findDir = 1;
            findTailAdd = -1;
            return vifindchar(false);
        }
        return false;
    }

    protected boolean viFindPrevCharSkip() {
        if ((findChar = vigetkey()) > 0) {
            findDir = -1;
            findTailAdd = 1;
            return vifindchar(false);
        }
        return false;
    }

    protected boolean viRepeatFind() {
        return vifindchar(true);
    }

    protected boolean viRevRepeatFind() {
        if (count < 0) {
            return callNeg(() -> vifindchar(true));
        }
        findTailAdd = -findTailAdd;
        findDir = -findDir;
        boolean ret = vifindchar(true);
        findTailAdd = -findTailAdd;
        findDir = -findDir;
        return ret;
    }

    private int vigetkey() {
        int ch = readCharacter();
        KeyMap<Binding> km = keyMaps.get(MAIN);
        if (km != null) {
            Binding b = km.getBound(new String(Character.toChars(ch)));
            if (b instanceof Reference) {
                String func = ((Reference) b).name();
                if (SEND_BREAK.equals(func)) {
                    return -1;
                }
            }
        }
        return ch;
    }

    private boolean vifindchar(boolean repeat) {
        if (findDir == 0) {
            return false;
        }
        if (count < 0) {
            return callNeg(this::viRevRepeatFind);
        }
        if (repeat && findTailAdd != 0) {
            if (findDir > 0) {
                if (buf.cursor() < buf.length() && buf.nextChar() == findChar) {
                    buf.move(1);
                }
            } else {
                if (buf.cursor() > 0 && buf.prevChar() == findChar) {
                    buf.move(-1);
                }
            }
        }
        int cursor = buf.cursor();
        while (count-- > 0) {
            do {
                buf.move(findDir);
            } while (buf.cursor() > 0 && buf.cursor() < buf.length()
                    && buf.currChar() != findChar
                    && buf.currChar() != '\n');
            if (buf.cursor() <= 0 || buf.cursor() >= buf.length()
                    || buf.currChar() == '\n') {
                buf.cursor(cursor);
                return false;
            }
        }
        if (findTailAdd != 0) {
            buf.move(findTailAdd);
        }
        if (findDir == 1 && isInViMoveOperation()) {
            buf.move(1);
        }
        return true;
    }

    private boolean callNeg(Widget widget) {
        this.count = -this.count;
        boolean ret = widget.apply();
        this.count = -this.count;
        return ret;
    }

    
Implements vi search ("/" or "?").
Returns:
true if the search was successful/**
     * Implements vi search ("/" or "?").
     *
     * @return <code>true</code> if the search was successful
     */
    protected boolean viHistorySearchForward() {
        searchDir = 1;
        searchIndex = 0;
        return getViSearchString() && viRepeatSearch();
    }

    protected boolean viHistorySearchBackward() {
        searchDir = -1;
        searchIndex = history.size() - 1;
        return getViSearchString() && viRepeatSearch();
    }

    protected boolean viRepeatSearch() {
        if (searchDir == 0) {
            return false;
        }
        int si = searchDir < 0
                ? searchBackwards(searchString, searchIndex, false)
                : searchForwards(searchString, searchIndex, false);
        if (si == -1 || si == history.index()) {
            return false;
        }
        searchIndex = si;

        /*
         * Show the match.
         */
        buf.clear();
        history.moveTo(searchIndex);
        buf.write(history.get(searchIndex));
        if (VICMD.equals(keyMap)) {
            buf.move(-1);
        }
        return true;
    }

    protected boolean viRevRepeatSearch() {
        boolean ret;
        searchDir = -searchDir;
        ret = viRepeatSearch();
        searchDir = -searchDir;
        return ret;
    }

    private boolean getViSearchString() {
        if (searchDir == 0) {
            return false;
        }
        String searchPrompt = searchDir < 0 ? "?" : "/";
        Buffer searchBuffer = new BufferImpl();

        KeyMap<Binding> keyMap = keyMaps.get(MAIN);
        if (keyMap == null) {
            keyMap = keyMaps.get(SAFE);
        }
        while (true) {
            post = () -> new AttributedString(searchPrompt + searchBuffer.toString() + "_");
            redisplay();
            Binding b = bindingReader.readBinding(keyMap);
            if (b instanceof Reference) {
                String func = ((Reference) b).name();
                switch (func) {
                    case SEND_BREAK:
                        post = null;
                        return false;
                    case ACCEPT_LINE:
                    case VI_CMD_MODE:
                        searchString = searchBuffer.toString();
                        post = null;
                        return true;
                    case MAGIC_SPACE:
                        searchBuffer.write(' ');
                        break;
                    case REDISPLAY:
                        redisplay();
                        break;
                    case CLEAR_SCREEN:
                        clearScreen();
                        break;
                    case SELF_INSERT:
                        searchBuffer.write(getLastBinding());
                        break;
                    case SELF_INSERT_UNMETA:
                        if (getLastBinding().charAt(0) == '\u001b') {
                            String s = getLastBinding().substring(1);
                            if ("\r".equals(s)) {
                                s = "\n";
                            }
                            searchBuffer.write(s);
                        }
                        break;
                    case BACKWARD_DELETE_CHAR:
                    case VI_BACKWARD_DELETE_CHAR:
                        if (searchBuffer.length() > 0) {
                            searchBuffer.backspace();
                        }
                        break;
                    case BACKWARD_KILL_WORD:
                    case VI_BACKWARD_KILL_WORD:
                        if (searchBuffer.length() > 0 && !isWhitespace(searchBuffer.prevChar())) {
                            searchBuffer.backspace();
                        }
                        if (searchBuffer.length() > 0 && isWhitespace(searchBuffer.prevChar())) {
                            searchBuffer.backspace();
                        }
                        break;
                    case QUOTED_INSERT:
                    case VI_QUOTED_INSERT:
                        int c = readCharacter();
                        if (c >= 0) {
                            searchBuffer.write(c);
                        } else {
                            beep();
                        }
                        break;
                    default:
                        beep();
                        break;
                }
            }
        }
    }

    protected boolean insertCloseCurly() {
        return insertClose("}");
    }

    protected boolean insertCloseParen() {
        return insertClose(")");
    }

    protected boolean insertCloseSquare() {
        return insertClose("]");
    }

    protected boolean insertClose(String s) {
        putString(s);

        long blink = getLong(BLINK_MATCHING_PAREN, DEFAULT_BLINK_MATCHING_PAREN);
        if (blink <= 0) {
            return true;
        }

        int closePosition = buf.cursor();

        buf.move(-1);
        doViMatchBracket();
        redisplay();

        peekCharacter(blink);

        buf.cursor(closePosition);
        return true;
    }

    protected boolean viMatchBracket() {
        return doViMatchBracket();
    }

    protected boolean undefinedKey() {
        return false;
    }

    
Implements vi style bracket matching ("%" command). The matching
bracket for the current bracket type that you are sitting on is matched.
Returns:
true if it worked, false if the cursor was not on a bracket
  character or if there was no matching bracket./**
     * Implements vi style bracket matching ("%" command). The matching
     * bracket for the current bracket type that you are sitting on is matched.
     *
     * @return true if it worked, false if the cursor was not on a bracket
     *   character or if there was no matching bracket.
     */
    protected boolean doViMatchBracket() {
        int pos        = buf.cursor();

        if (pos == buf.length()) {
            return false;
        }

        int type       = getBracketType(buf.atChar(pos));
        int move       = (type < 0) ? -1 : 1;
        int count      = 1;

        if (type == 0)
            return false;

        while (count > 0) {
            pos += move;

            // Fell off the start or end.
            if (pos < 0 || pos >= buf.length()) {
                return false;
            }

            int curType = getBracketType(buf.atChar(pos));
            if (curType == type) {
                ++count;
            }
            else if (curType == -type) {
                --count;
            }
        }

        /*
         * Slight adjustment for delete-to, yank-to, change-to to ensure
         * that the matching paren is consumed
         */
        if (move > 0 && isInViMoveOperation())
            ++pos;

        buf.cursor(pos);
        return true;
    }

    
Given a character determines what type of bracket it is (paren,
square, curly, or none).
Params:
ch – The character to check
Returns:
1 is square, 2 curly, 3 parent, or zero for none.  The value
  will be negated if it is the closing form of the bracket./**
     * Given a character determines what type of bracket it is (paren,
     * square, curly, or none).
     * @param ch The character to check
     * @return 1 is square, 2 curly, 3 parent, or zero for none.  The value
     *   will be negated if it is the closing form of the bracket.
     */
    protected int getBracketType (int ch) {
        switch (ch) {
            case '[': return  1;
            case ']': return -1;
            case '{': return  2;
            case '}': return -2;
            case '(': return  3;
            case ')': return -3;
            default:
                return 0;
        }
    }

    
Performs character transpose. The character prior to the cursor and the
character under the cursor are swapped and the cursor is advanced one.
Do not cross line breaks.
Returns:
true/**
     * Performs character transpose. The character prior to the cursor and the
     * character under the cursor are swapped and the cursor is advanced one.
     * Do not cross line breaks.
     * @return true
     */
    protected boolean transposeChars() {
        int lstart = buf.cursor() - 1;
        int lend = buf.cursor();
        while (buf.atChar(lstart) != 0 && buf.atChar(lstart) != '\n') {
            lstart--;
        }
        lstart++;
        while (buf.atChar(lend) != 0 && buf.atChar(lend) != '\n') {
            lend++;
        }
        if (lend - lstart < 2) {
            return false;
        }
        boolean neg = this.count < 0;
        for (int count = Math.max(this.count, -this.count); count > 0; --count) {
            while (buf.cursor() <= lstart) {
                buf.move(1);
            }
            while (buf.cursor() >= lend) {
                buf.move(-1);
            }
            int c = buf.currChar();
            buf.currChar(buf.prevChar());
            buf.move(-1);
            buf.currChar(c);
            buf.move(neg ? 0 : 2);
        }
        return true;
    }

    protected boolean undo() {
        isUndo = true;
        if (undo.canUndo()) {
            undo.undo();
            return true;
        }
        return false;
    }

    protected boolean redo() {
        isUndo = true;
        if (undo.canRedo()) {
            undo.redo();
            return true;
        }
        return false;
    }

    protected boolean sendBreak() {
        if (searchTerm == null) {
            buf.clear();
            println();
            redrawLine();
//            state = State.INTERRUPT;
            return false;
        }
        return true;
    }

    protected boolean backwardChar() {
        return buf.move(-count) != 0;
    }

    protected boolean forwardChar() {
        return buf.move(count) != 0;
    }

    protected boolean viDigitOrBeginningOfLine() {
        if (repeatCount > 0) {
            return digitArgument();
        } else {
            return beginningOfLine();
        }
    }

    protected boolean universalArgument() {
        mult *= universal;
        isArgDigit = true;
        return true;
    }

    protected boolean argumentBase() {
        if (repeatCount > 0 && repeatCount < 32) {
            universal = repeatCount;
            isArgDigit = true;
            return true;
        } else {
            return false;
        }
    }

    protected boolean negArgument() {
        mult *= -1;
        isArgDigit = true;
        return true;
    }

    protected boolean digitArgument() {
        String s = getLastBinding();
        repeatCount = (repeatCount * 10) + s.charAt(s.length() - 1) - '0';
        isArgDigit = true;
        return true;
    }

    protected boolean viDelete() {
        int cursorStart = buf.cursor();
        Binding o = readBinding(getKeys());
        if (o instanceof Reference) {
            // TODO: be smarter on how to get the vi range
            String op = viDeleteChangeYankToRemap(((Reference) o).name());
            // This is a weird special case. In vi
            // "dd" deletes the current line. So if we
            // get a delete-to, followed by a delete-to,
            // we delete the line.
            if (VI_DELETE.equals(op)) {
                killWholeLine();
            } else {
                viMoveMode = ViMoveMode.DELETE;
                Widget widget = widgets.get(op);
                if (widget != null && !widget.apply()) {
                    viMoveMode = ViMoveMode.NORMAL;
                    return false;
                }
                viMoveMode = ViMoveMode.NORMAL;
            }
            return viDeleteTo(cursorStart, buf.cursor());
        } else {
            pushBackBinding();
            return false;
        }
    }

    protected boolean viYankTo() {
        int cursorStart = buf.cursor();
        Binding o = readBinding(getKeys());
        if (o instanceof Reference) {
            // TODO: be smarter on how to get the vi range
            String op = viDeleteChangeYankToRemap(((Reference) o).name());
            // Similar to delete-to, a "yy" yanks the whole line.
            if (VI_YANK.equals(op)) {
                yankBuffer = buf.toString();
                return true;
            } else {
                viMoveMode = ViMoveMode.YANK;
                Widget widget = widgets.get(op);
                if (widget != null && !widget.apply()) {
                    return false;
                }
                viMoveMode = ViMoveMode.NORMAL;
            }
            return viYankTo(cursorStart, buf.cursor());
        } else {
            pushBackBinding();
            return false;
        }
    }

    protected boolean viYankWholeLine() {
        int s, e;
        int p = buf.cursor();
        while (buf.move(-1) == -1 && buf.prevChar() != '\n') ;
        s = buf.cursor();
        for (int i = 0; i < repeatCount; i++) {
            while (buf.move(1) == 1 && buf.prevChar() != '\n') ;
        }
        e = buf.cursor();
        yankBuffer = buf.substring(s, e);
        if (!yankBuffer.endsWith("\n")) {
            yankBuffer += "\n";
        }
        buf.cursor(p);
        return true;
    }

    protected boolean viChange() {
        int cursorStart = buf.cursor();
        Binding o = readBinding(getKeys());
        if (o instanceof Reference) {
            // TODO: be smarter on how to get the vi range
            String op = viDeleteChangeYankToRemap(((Reference) o).name());
            // change whole line
            if (VI_CHANGE.equals(op)) {
                killWholeLine();
            } else {
                viMoveMode = ViMoveMode.CHANGE;
                Widget widget = widgets.get(op);
                if (widget != null && !widget.apply()) {
                    viMoveMode = ViMoveMode.NORMAL;
                    return false;
                }
                viMoveMode = ViMoveMode.NORMAL;
            }
            boolean res = viChange(cursorStart, buf.cursor());
            setKeyMap(VIINS);
            return res;
        } else {
            pushBackBinding();
            return false;
        }
    }

    /*
    protected int getViRange(Reference cmd, ViMoveMode mode) {
        Buffer buffer = buf.copy();
        int oldMark = mark;
        int pos = buf.cursor();
        String bind = getLastBinding();

        if (visual != 0) {
            if (buf.length() == 0) {
                return -1;
            }
            pos = mark;
            v
        } else {
            viMoveMode = mode;
            mark = -1;
            Binding b = bindingReader.readBinding(getKeys(), keyMaps.get(VIOPP));
            if (b == null || new Reference(SEND_BREAK).equals(b)) {
                viMoveMode = ViMoveMode.NORMAL;
                mark = oldMark;
                return -1;
            }
            if (cmd.equals(b)) {
                doViLineRange();
            }
            Widget w = getWidget(b);
            if (w )
            if (b instanceof Reference) {

            }
        }

    }
    */

    protected void cleanup() {
        if (isSet(Option.ERASE_LINE_ON_FINISH)) {
            Buffer oldBuffer = buf.copy();
            AttributedString oldPrompt = prompt;
            buf.clear();
            prompt = new AttributedString("");
            doCleanup(false);
            prompt = oldPrompt;
            buf.copyFrom(oldBuffer);
        } else {
            doCleanup(true);
        }
    }

    protected void doCleanup(boolean nl) {
        buf.cursor(buf.length());
        post = null;
        if (size.getColumns() > 0 || size.getRows() > 0) {
            redisplay(false);
            if (nl) {
                println();
            }
            terminal.puts(Capability.keypad_local);
            terminal.trackMouse(Terminal.MouseTracking.Off);
            if (isSet(Option.BRACKETED_PASTE))
                terminal.writer().write(BRACKETED_PASTE_OFF);
            flush();
        }
        history.moveToEnd();
    }

    protected boolean historyIncrementalSearchForward() {
        return doSearchHistory(false);
    }

    protected boolean historyIncrementalSearchBackward() {
        return doSearchHistory(true);
    }

    static class Pair<U,V> {
        final U u; final V v;
        public Pair(U u, V v) {
            this.u = u;
            this.v = v;
        }
        public U getU() {
            return u;
        }
        public V getV() {
            return v;
        }
    }

    protected boolean doSearchHistory(boolean backward) {
        if (history.isEmpty()) {
            return false;
        }

        KeyMap<Binding> terminators = new KeyMap<>();
        getString(SEARCH_TERMINATORS, DEFAULT_SEARCH_TERMINATORS)
                .codePoints().forEach(c -> bind(terminators, ACCEPT_LINE, new String(Character.toChars(c))));

        Buffer originalBuffer = buf.copy();
        searchIndex = -1;
        searchTerm = new StringBuffer();
        searchBackward = backward;
        searchFailing = false;
        post = () -> new AttributedString((searchFailing ? "failing" + " " : "")
                        + (searchBackward ? "bck-i-search" : "fwd-i-search")
                        + ": " + searchTerm + "_");

        redisplay();
        try {
            while (true) {
                int prevSearchIndex = searchIndex;
                Binding operation = readBinding(getKeys(), terminators);
                String ref = (operation instanceof Reference) ? ((Reference) operation).name() : "";
                boolean next = false;
                switch (ref) {
                    case SEND_BREAK:
                        beep();
                        buf.copyFrom(originalBuffer);
                        return true;
                    case HISTORY_INCREMENTAL_SEARCH_BACKWARD:
                        searchBackward = true;
                        next = true;
                        break;
                    case HISTORY_INCREMENTAL_SEARCH_FORWARD:
                        searchBackward = false;
                        next = true;
                        break;
                    case BACKWARD_DELETE_CHAR:
                        if (searchTerm.length() > 0) {
                            searchTerm.deleteCharAt(searchTerm.length() - 1);
                        }
                        break;
                    case SELF_INSERT:
                        searchTerm.append(getLastBinding());
                        break;
                    default:
                        // Set buffer and cursor position to the found string.
                        if (searchIndex != -1) {
                            history.moveTo(searchIndex);
                        }
                        pushBackBinding();
                        return true;
                }

                // print the search status
                String pattern = doGetSearchPattern();
                if (pattern.length() == 0) {
                    buf.copyFrom(originalBuffer);
                    searchFailing = false;
                } else {
                    boolean caseInsensitive = isSet(Option.CASE_INSENSITIVE_SEARCH);
                    Pattern pat = Pattern.compile(pattern, caseInsensitive ? Pattern.CASE_INSENSITIVE | Pattern.UNICODE_CASE
                                                                           : Pattern.UNICODE_CASE);
                    Pair<Integer, Integer> pair = null;
                    if (searchBackward) {
                        boolean nextOnly = next;
                        pair = matches(pat, buf.toString(), searchIndex).stream()
                                .filter(p -> nextOnly ? p.v < buf.cursor() : p.v <= buf.cursor())
                                .max(Comparator.comparing(Pair::getV))
                                .orElse(null);
                        if (pair == null) {
                            pair = StreamSupport.stream(
                                    Spliterators.spliteratorUnknownSize(history.reverseIterator(searchIndex < 0 ? history.last() : searchIndex - 1), Spliterator.ORDERED), false)
                                    .flatMap(e -> matches(pat, e.line(), e.index()).stream())
                                    .findFirst()
                                    .orElse(null);
                        }
                    } else {
                        boolean nextOnly = next;
                        pair = matches(pat, buf.toString(), searchIndex).stream()
                                .filter(p -> nextOnly ? p.v > buf.cursor() : p.v >= buf.cursor())
                                .min(Comparator.comparing(Pair::getV))
                                .orElse(null);
                        if (pair == null) {
                            pair = StreamSupport.stream(
                                    Spliterators.spliteratorUnknownSize(history.iterator((searchIndex < 0 ? history.last() : searchIndex) + 1), Spliterator.ORDERED), false)
                                    .flatMap(e -> matches(pat, e.line(), e.index()).stream())
                                    .findFirst()
                                    .orElse(null);
                            if (pair == null && searchIndex >= 0) {
                                pair = matches(pat, originalBuffer.toString(), -1).stream()
                                        .min(Comparator.comparing(Pair::getV))
                                        .orElse(null);
                            }
                        }
                    }
                    if (pair != null) {
                        searchIndex = pair.u;
                        buf.clear();
                        if (searchIndex >= 0) {
                            buf.write(history.get(searchIndex));
                        } else {
                            buf.write(originalBuffer.toString());
                        }
                        buf.cursor(pair.v);
                        searchFailing = false;
                    } else {
                        searchFailing = true;
                        beep();
                    }
                }
                redisplay();
            }
        } catch (IOError e) {
            // Ignore Ctrl+C interrupts and just exit the loop
            if (!(e.getCause() instanceof InterruptedException)) {
                throw e;
            }
            return true;
        } finally {
            searchTerm = null;
            searchIndex = -1;
            post = null;
        }
    }

    private List<Pair<Integer, Integer>> matches(Pattern p, String line, int index) {
        List<Pair<Integer, Integer>> starts = new ArrayList<>();
        Matcher m = p.matcher(line);
        while (m.find()) {
            starts.add(new Pair<>(index, m.start()));
        }
        return starts;
   }

    private String doGetSearchPattern() {
        StringBuilder sb = new StringBuilder();
        boolean inQuote = false;
        for (int i = 0; i < searchTerm.length(); i++) {
            char c = searchTerm.charAt(i);
            if (Character.isLowerCase(c)) {
                if (inQuote) {
                    sb.append("\\E");
                    inQuote = false;
                }
                sb.append("[").append(Character.toLowerCase(c)).append(Character.toUpperCase(c)).append("]");
            } else {
                if (!inQuote) {
                    sb.append("\\Q");
                    inQuote = true;
                }
                sb.append(c);
            }
        }
        if (inQuote) {
            sb.append("\\E");
        }
        return sb.toString();
    }

    private void pushBackBinding() {
        pushBackBinding(false);
    }

    private void pushBackBinding(boolean skip) {
        String s = getLastBinding();
        if (s != null) {
            bindingReader.runMacro(s);
            skipRedisplay = skip;
        }
    }

    protected boolean historySearchForward() {
        if (historyBuffer == null || buf.length() == 0
                || !buf.toString().equals(history.current())) {
            historyBuffer = buf.copy();
            searchBuffer = getFirstWord();
        }
        int index = history.index() + 1;

        if (index < history.last() + 1) {
            int searchIndex = searchForwards(searchBuffer.toString(), index, true);
            if (searchIndex == -1) {
                history.moveToEnd();
                if (!buf.toString().equals(historyBuffer.toString())) {
                    setBuffer(historyBuffer.toString());
                    historyBuffer = null;
                } else {
                    return false;
                }
            } else {
                // Maintain cursor position while searching.
                if (history.moveTo(searchIndex)) {
                    setBuffer(history.current());
                } else {
                    history.moveToEnd();
                    setBuffer(historyBuffer.toString());
                    return false;
                }
            }
        } else {
            history.moveToEnd();
            if (!buf.toString().equals(historyBuffer.toString())) {
                setBuffer(historyBuffer.toString());
                historyBuffer = null;
            } else {
                return false;
            }
        }
        return true;
    }

    private CharSequence getFirstWord() {
        String s = buf.toString();
        int i = 0;
        while (i < s.length() && !Character.isWhitespace(s.charAt(i))) {
            i++;
        }
        return s.substring(0, i);
    }

    protected boolean historySearchBackward() {
        if (historyBuffer == null || buf.length() == 0
                || !buf.toString().equals(history.current())) {
            historyBuffer = buf.copy();
            searchBuffer = getFirstWord();
        }
        int searchIndex = searchBackwards(searchBuffer.toString(), history.index(), true);

        if (searchIndex == -1) {
            return false;
        } else {
            // Maintain cursor position while searching.
            if (history.moveTo(searchIndex)) {
                setBuffer(history.current());
            } else {
                return false;
            }
        }
        return true;
    }

    //
    // History search
    //
    
Search backward in history from a given position.
Params:
searchTerm – substring to search for.
startIndex – the index from which on to search
Returns:
index where this substring has been found, or -1 else./**
     * Search backward in history from a given position.
     *
     * @param searchTerm substring to search for.
     * @param startIndex the index from which on to search
     * @return index where this substring has been found, or -1 else.
     */
    public int searchBackwards(String searchTerm, int startIndex) {
        return searchBackwards(searchTerm, startIndex, false);
    }

    
Search backwards in history from the current position.
Params:
searchTerm – substring to search for.
Returns:
index where the substring has been found, or -1 else./**
     * Search backwards in history from the current position.
     *
     * @param searchTerm substring to search for.
     * @return index where the substring has been found, or -1 else.
     */
    public int searchBackwards(String searchTerm) {
        return searchBackwards(searchTerm, history.index(), false);
    }

    public int searchBackwards(String searchTerm, int startIndex, boolean startsWith) {
        boolean caseInsensitive = isSet(Option.CASE_INSENSITIVE_SEARCH);
        if (caseInsensitive) {
            searchTerm = searchTerm.toLowerCase();
        }
        ListIterator<History.Entry> it = history.iterator(startIndex);
        while (it.hasPrevious()) {
            History.Entry e = it.previous();
            String line = e.line();
            if (caseInsensitive) {
                line = line.toLowerCase();
            }
            int idx = line.indexOf(searchTerm);
            if ((startsWith && idx == 0) || (!startsWith && idx >= 0)) {
                return e.index();
            }
        }
        return -1;
    }

    public int searchForwards(String searchTerm, int startIndex, boolean startsWith) {
        boolean caseInsensitive = isSet(Option.CASE_INSENSITIVE_SEARCH);
        if (caseInsensitive) {
            searchTerm = searchTerm.toLowerCase();
        }
        if (startIndex > history.last()) {
            startIndex = history.last();
        }
        ListIterator<History.Entry> it = history.iterator(startIndex);
        if (searchIndex != -1 && it.hasNext()) {
            it.next();
        }
        while (it.hasNext()) {
            History.Entry e = it.next();
            String line = e.line();
            if (caseInsensitive) {
                line = line.toLowerCase();
            }
            int idx = line.indexOf(searchTerm);
            if ((startsWith && idx == 0) || (!startsWith && idx >= 0)) {
                return e.index();
            }
        }
        return -1;
    }

    
Search forward in history from a given position.
Params:
searchTerm – substring to search for.
startIndex – the index from which on to search
Returns:
index where this substring has been found, or -1 else./**
     * Search forward in history from a given position.
     *
     * @param searchTerm substring to search for.
     * @param startIndex the index from which on to search
     * @return index where this substring has been found, or -1 else.
     */
    public int searchForwards(String searchTerm, int startIndex) {
        return searchForwards(searchTerm, startIndex, false);
    }
    
Search forwards in history from the current position.
Params:
searchTerm – substring to search for.
Returns:
index where the substring has been found, or -1 else./**
     * Search forwards in history from the current position.
     *
     * @param searchTerm substring to search for.
     * @return index where the substring has been found, or -1 else.
     */
    public int searchForwards(String searchTerm) {
        return searchForwards(searchTerm, history.index());
    }

    protected boolean quit() {
        getBuffer().clear();
        return acceptLine();
    }

    protected boolean acceptLine() {
        parsedLine = null;
        if (!isSet(Option.DISABLE_EVENT_EXPANSION)) {
            try {
                String str = buf.toString();
                String exp = expander.expandHistory(history, str);
                if (!exp.equals(str)) {
                    buf.clear();
                    buf.write(exp);
                    if (isSet(Option.HISTORY_VERIFY)) {
                        return true;
                    }
                }
            } catch (IllegalArgumentException e) {
                // Ignore
            }
        }
        try {
            parsedLine = parser.parse(buf.toString(), buf.cursor(), ParseContext.ACCEPT_LINE);
        } catch (EOFError e) {
            buf.write("\n");
            return true;
        } catch (SyntaxError e) {
            // do nothing
        }
        callWidget(CALLBACK_FINISH);
        state = State.DONE;
        return true;
    }

    protected boolean selfInsert() {
        for (int count = this.count; count > 0; count--) {
            putString(getLastBinding());
        }
        return true;
    }

    protected boolean selfInsertUnmeta() {
        if (getLastBinding().charAt(0) == '\u001b') {
            String s = getLastBinding().substring(1);
            if ("\r".equals(s)) {
                s = "\n";
            }
            for (int count = this.count; count > 0; count--) {
                putString(s);
            }
            return true;
        } else {
            return false;
        }
    }

    protected boolean overwriteMode() {
        overTyping = !overTyping;
        return true;
    }


    //
    // History Control
    //

    protected boolean beginningOfBufferOrHistory() {
        if (findbol() != 0) {
            buf.cursor(0);
            return true;
        } else {
            return beginningOfHistory();
        }
    }

    protected boolean beginningOfHistory() {
        if (history.moveToFirst()) {
            setBuffer(history.current());
            return true;
        } else {
            return false;
        }
    }

    protected boolean endOfBufferOrHistory() {
        if (findeol() != buf.length()) {
            buf.cursor(buf.length());
            return true;
        } else {
            return endOfHistory();
        }
    }

    protected boolean endOfHistory() {
        if (history.moveToLast()) {
            setBuffer(history.current());
            return true;
        } else {
            return false;
        }
    }

    protected boolean beginningOfLineHist() {
        if (count < 0) {
            return callNeg(this::endOfLineHist);
        }
        while (count-- > 0) {
            int bol = findbol();
            if (bol != buf.cursor()) {
                buf.cursor(bol);
            } else {
                moveHistory(false);
                buf.cursor(0);
            }
        }
        return true;
    }

    protected boolean endOfLineHist() {
        if (count < 0) {
            return callNeg(this::beginningOfLineHist);
        }
        while (count-- > 0) {
            int eol = findeol();
            if (eol != buf.cursor()) {
                buf.cursor(eol);
            } else {
                moveHistory(true);
            }
        }
        return true;
    }

    protected boolean upHistory() {
        while (count-- > 0) {
            if (!moveHistory(false)) {
                return !isSet(Option.HISTORY_BEEP);
            }
        }
        return true;
    }

    protected boolean downHistory() {
        while (count-- > 0) {
            if (!moveHistory(true)) {
                return !isSet(Option.HISTORY_BEEP);
            }
        }
        return true;
    }

    protected boolean viUpLineOrHistory() {
        return upLine()
                || upHistory() && viFirstNonBlank();
    }

    protected boolean viDownLineOrHistory() {
        return downLine()
                || downHistory() && viFirstNonBlank();
    }

    protected boolean upLine() {
        return buf.up();
    }

    protected boolean downLine() {
        return buf.down();
    }

    protected boolean upLineOrHistory() {
        return upLine() || upHistory();
    }

    protected boolean upLineOrSearch() {
        return upLine() || historySearchBackward();
    }

    protected boolean downLineOrHistory() {
        return downLine() || downHistory();
    }

    protected boolean downLineOrSearch() {
        return downLine() || historySearchForward();
    }

    protected boolean viCmdMode() {
        // If we are re-entering move mode from an
        // aborted yank-to, delete-to, change-to then
        // don't move the cursor back. The cursor is
        // only move on an explicit entry to movement
        // mode.
        if (state == State.NORMAL) {
            buf.move(-1);
        }
        return setKeyMap(VICMD);
    }

    protected boolean viInsert() {
        return setKeyMap(VIINS);
    }

    protected boolean viAddNext() {
        buf.move(1);
        return setKeyMap(VIINS);
    }

    protected boolean viAddEol() {
        return endOfLine() && setKeyMap(VIINS);
    }

    protected boolean emacsEditingMode() {
        return setKeyMap(EMACS);
    }

    protected boolean viChangeWholeLine() {
        return viFirstNonBlank() && viChangeEol();
    }

    protected boolean viChangeEol() {
        return viChange(buf.cursor(), buf.length())
                && setKeyMap(VIINS);
    }

    protected boolean viKillEol() {
        int eol = findeol();
        if (buf.cursor() == eol) {
            return false;
        }
        killRing.add(buf.substring(buf.cursor(), eol));
        buf.delete(eol - buf.cursor());
        return true;
    }

    protected boolean quotedInsert() {
        int c = readCharacter();
        while (count-- > 0) {
            putString(new String(Character.toChars(c)));
        }
        return true;
    }

    protected boolean viJoin() {
        if (buf.down()) {
            while (buf.move(-1) == -1 && buf.prevChar() != '\n') ;
            buf.backspace();
            buf.write(' ');
            buf.move(-1);
            return true;
        }
        return false;
    }

    protected boolean viKillWholeLine() {
        return killWholeLine() && setKeyMap(VIINS);
    }

    protected boolean viInsertBol() {
        return beginningOfLine() && setKeyMap(VIINS);
    }

    protected boolean backwardDeleteChar() {
        if (count < 0) {
            return callNeg(this::deleteChar);
        }
        if (buf.cursor() == 0) {
            return false;
        }
        buf.backspace(count);
        return true;
    }

    protected boolean viFirstNonBlank() {
        beginningOfLine();
        while (buf.cursor() < buf.length() && isWhitespace(buf.currChar())) {
            buf.move(1);
        }
        return true;
    }

    protected boolean viBeginningOfLine() {
        buf.cursor(findbol());
        return true;
    }

    protected boolean viEndOfLine() {
        if (count < 0) {
            return false;
        }
        while (count-- > 0) {
            buf.cursor(findeol() + 1);
        }
        buf.move(-1);
        return true;
    }

    protected boolean beginningOfLine() {
        while (count-- > 0) {
            while (buf.move(-1) == -1 && buf.prevChar() != '\n') ;
        }
        return true;
    }

    protected boolean endOfLine() {
        while (count-- > 0) {
            while (buf.move(1) == 1 && buf.currChar() != '\n') ;
        }
        return true;
    }

    protected boolean deleteChar() {
        if (count < 0) {
            return callNeg(this::backwardDeleteChar);
        }
        if (buf.cursor() == buf.length()) {
            return false;
        }
        buf.delete(count);
        return true;
    }

    
Deletes the previous character from the cursor position
Returns:
true if it succeeded, false otherwise/**
     * Deletes the previous character from the cursor position
     * @return <code>true</code> if it succeeded, <code>false</code> otherwise
     */
    protected boolean viBackwardDeleteChar() {
        for (int i = 0; i < count; i++) {
            if (!buf.backspace()) {
                return false;
            }
        }
        return true;
    }

    
Deletes the character you are sitting on and sucks the rest of
the line in from the right.
Returns:
true if it succeeded, false otherwise/**
     * Deletes the character you are sitting on and sucks the rest of
     * the line in from the right.
     * @return <code>true</code> if it succeeded, <code>false</code> otherwise
     */
    protected boolean viDeleteChar() {
        for (int i = 0; i < count; i++) {
            if (!buf.delete()) {
                return false;
            }
        }
        return true;
    }

    
Switches the case of the current character from upper to lower
or lower to upper as necessary and advances the cursor one
position to the right.
Returns:
true if it succeeded, false otherwise/**
     * Switches the case of the current character from upper to lower
     * or lower to upper as necessary and advances the cursor one
     * position to the right.
     * @return <code>true</code> if it succeeded, <code>false</code> otherwise
     */
    protected boolean viSwapCase() {
        for (int i = 0; i < count; i++) {
            if (buf.cursor() < buf.length()) {
                int ch = buf.atChar(buf.cursor());
                ch = switchCase(ch);
                buf.currChar(ch);
                buf.move(1);
            } else {
                return false;
            }
        }
        return true;
    }

    
Implements the vi change character command (in move-mode "r"
followed by the character to change to).
Returns:
true if it succeeded, false otherwise/**
     * Implements the vi change character command (in move-mode "r"
     * followed by the character to change to).
     * @return <code>true</code> if it succeeded, <code>false</code> otherwise
     */
    protected boolean viReplaceChars() {
        int c = readCharacter();
        // EOF, ESC, or CTRL-C aborts.
        if (c < 0 || c == '\033' || c == '\003') {
            return true;
        }

        for (int i = 0; i < count; i++) {
            if (buf.currChar((char) c)) {
                if (i < count - 1) {
                    buf.move(1);
                }
            } else {
                return false;
            }
        }
        return true;
    }

    protected boolean viChange(int startPos, int endPos) {
        return doViDeleteOrChange(startPos, endPos, true);
    }

    protected boolean viDeleteTo(int startPos, int endPos) {
        return doViDeleteOrChange(startPos, endPos, false);
    }

    
Performs the vi "delete-to" action, deleting characters between a given
span of the input line.
Params:
startPos – The start position
endPos – The end position.
isChange – If true, then the delete is part of a change operationg
   (e.g. "c$" is change-to-end-of line, so we first must delete to end
   of line to start the change
Returns:
true if it succeeded, false otherwise/**
     * Performs the vi "delete-to" action, deleting characters between a given
     * span of the input line.
     * @param startPos The start position
     * @param endPos The end position.
     * @param isChange If true, then the delete is part of a change operationg
     *    (e.g. "c$" is change-to-end-of line, so we first must delete to end
     *    of line to start the change
     * @return <code>true</code> if it succeeded, <code>false</code> otherwise
     */
    protected boolean doViDeleteOrChange(int startPos, int endPos, boolean isChange) {
        if (startPos == endPos) {
            return true;
        }

        if (endPos < startPos) {
            int tmp = endPos;
            endPos = startPos;
            startPos = tmp;
        }

        buf.cursor(startPos);
        buf.delete(endPos - startPos);

        // If we are doing a delete operation (e.g. "d$") then don't leave the
        // cursor dangling off the end. In reality the "isChange" flag is silly
        // what is really happening is that if we are in "move-mode" then the
        // cursor can't be moved off the end of the line, but in "edit-mode" it
        // is ok, but I have no easy way of knowing which mode we are in.
        if (! isChange && startPos > 0 && startPos == buf.length()) {
            buf.move(-1);
        }
        return true;
    }

    
Implement the "vi" yank-to operation.  This operation allows you
to yank the contents of the current line based upon a move operation,
for example "yw" yanks the current word, "3yw" yanks 3 words, etc.
Params:
startPos – The starting position from which to yank
endPos – The ending position to which to yank
Returns:
true if the yank succeeded/**
     * Implement the "vi" yank-to operation.  This operation allows you
     * to yank the contents of the current line based upon a move operation,
     * for example "yw" yanks the current word, "3yw" yanks 3 words, etc.
     *
     * @param startPos The starting position from which to yank
     * @param endPos The ending position to which to yank
     * @return <code>true</code> if the yank succeeded
     */
    protected boolean viYankTo(int startPos, int endPos) {
        int cursorPos = startPos;

        if (endPos < startPos) {
            int tmp = endPos;
            endPos = startPos;
            startPos = tmp;
        }

        if (startPos == endPos) {
            yankBuffer = "";
            return true;
        }

        yankBuffer = buf.substring(startPos, endPos);

        /*
         * It was a movement command that moved the cursor to find the
         * end position, so put the cursor back where it started.
         */
        buf.cursor(cursorPos);
        return true;
    }

    protected boolean viOpenLineAbove() {
        while (buf.move(-1) == -1 && buf.prevChar() != '\n') ;
        buf.write('\n');
        buf.move(-1);
        return setKeyMap(VIINS);
    }

    protected boolean viOpenLineBelow() {
        while (buf.move(1) == 1 && buf.currChar() != '\n') ;
        buf.write('\n');
        return setKeyMap(VIINS);
    }

    
Pasts the yank buffer to the right of the current cursor position
and moves the cursor to the end of the pasted region.
Returns:
true/**
     * Pasts the yank buffer to the right of the current cursor position
     * and moves the cursor to the end of the pasted region.
     * @return <code>true</code>
     */
    protected boolean viPutAfter() {
        if (yankBuffer.indexOf('\n') >= 0) {
            while (buf.move(1) == 1 && buf.currChar() != '\n');
            buf.move(1);
            putString(yankBuffer);
            buf.move(- yankBuffer.length());
        } else if (yankBuffer.length () != 0) {
            if (buf.cursor() < buf.length()) {
                buf.move(1);
            }
            for (int i = 0; i < count; i++) {
                putString(yankBuffer);
            }
            buf.move(-1);
        }
        return true;
    }

    protected boolean viPutBefore() {
        if (yankBuffer.indexOf('\n') >= 0) {
            while (buf.move(-1) == -1 && buf.prevChar() != '\n');
            putString(yankBuffer);
            buf.move(- yankBuffer.length());
        } else if (yankBuffer.length () != 0) {
            if (buf.cursor() > 0) {
                buf.move(-1);
            }
            for (int i = 0; i < count; i++) {
                putString(yankBuffer);
            }
            buf.move(-1);
        }
        return true;
    }

    protected boolean doLowercaseVersion() {
        bindingReader.runMacro(getLastBinding().toLowerCase());
        return true;
    }

    protected boolean setMarkCommand() {
        if (count < 0) {
            regionActive = RegionType.NONE;
            return true;
        }
        regionMark = buf.cursor();
        regionActive = RegionType.CHAR;
        return true;
    }

    protected boolean exchangePointAndMark() {
        if (count == 0) {
            regionActive = RegionType.CHAR;
            return true;
        }
        int x = regionMark;
        regionMark = buf.cursor();
        buf.cursor(x);
        if (buf.cursor() > buf.length()) {
            buf.cursor(buf.length());
        }
        if (count > 0) {
            regionActive = RegionType.CHAR;
        }
        return true;
    }

    protected boolean visualMode() {
        if (isInViMoveOperation()) {
            isArgDigit = true;
            forceLine = false;
            forceChar = true;
            return true;
        }
        if (regionActive == RegionType.NONE) {
            regionMark = buf.cursor();
            regionActive = RegionType.CHAR;
        } else if (regionActive == RegionType.CHAR) {
            regionActive = RegionType.NONE;
        } else if (regionActive == RegionType.LINE) {
            regionActive = RegionType.CHAR;
        }
        return true;
    }

    protected boolean visualLineMode() {
        if (isInViMoveOperation()) {
            isArgDigit = true;
            forceLine = true;
            forceChar = false;
            return true;
        }
        if (regionActive == RegionType.NONE) {
            regionMark = buf.cursor();
            regionActive = RegionType.LINE;
        } else if (regionActive == RegionType.CHAR) {
            regionActive = RegionType.LINE;
        } else if (regionActive == RegionType.LINE) {
            regionActive = RegionType.NONE;
        }
        return true;
    }

    protected boolean deactivateRegion() {
        regionActive = RegionType.NONE;
        return true;
    }

    protected boolean whatCursorPosition() {
        post = () -> {
            AttributedStringBuilder sb = new AttributedStringBuilder();
            if (buf.cursor() < buf.length()) {
                int c = buf.currChar();
                sb.append("Char: ");
                if (c == ' ') {
                    sb.append("SPC");
                } else if (c == '\n') {
                    sb.append("LFD");
                } else if (c < 32) {
                    sb.append('^');
                    sb.append((char) (c + 'A' - 1));
                } else if (c == 127) {
                    sb.append("^?");
                } else {
                    sb.append((char) c);
                }
                sb.append(" (");
                sb.append("0").append(Integer.toOctalString(c)).append(" ");
                sb.append(Integer.toString(c)).append(" ");
                sb.append("0x").append(Integer.toHexString(c)).append(" ");
                sb.append(")");
            } else {
                sb.append("EOF");
            }
            sb.append("   ");
            sb.append("point ");
            sb.append(Integer.toString(buf.cursor() + 1));
            sb.append(" of ");
            sb.append(Integer.toString(buf.length() + 1));
            sb.append(" (");
            sb.append(Integer.toString(buf.length() == 0 ? 100 : ((100 * buf.cursor()) / buf.length())));
            sb.append("%)");
            sb.append("   ");
            sb.append("column ");
            sb.append(Integer.toString(buf.cursor() - findbol()));
            return sb.toAttributedString();
        };
        return true;
    }

    protected Map<String, Widget> builtinWidgets() {
        Map<String, Widget> widgets = new HashMap<>();
        widgets.put(ACCEPT_LINE, this::acceptLine);
        widgets.put(ARGUMENT_BASE, this::argumentBase);
        widgets.put(BACKWARD_CHAR, this::backwardChar);
        widgets.put(BACKWARD_DELETE_CHAR, this::backwardDeleteChar);
        widgets.put(BACKWARD_DELETE_WORD, this::backwardDeleteWord);
        widgets.put(BACKWARD_KILL_LINE, this::backwardKillLine);
        widgets.put(BACKWARD_KILL_WORD, this::backwardKillWord);
        widgets.put(BACKWARD_WORD, this::backwardWord);
        widgets.put(BEEP, this::beep);
        widgets.put(BEGINNING_OF_BUFFER_OR_HISTORY, this::beginningOfBufferOrHistory);
        widgets.put(BEGINNING_OF_HISTORY, this::beginningOfHistory);
        widgets.put(BEGINNING_OF_LINE, this::beginningOfLine);
        widgets.put(BEGINNING_OF_LINE_HIST, this::beginningOfLineHist);
        widgets.put(CAPITALIZE_WORD, this::capitalizeWord);
        widgets.put(CLEAR, this::clear);
        widgets.put(CLEAR_SCREEN, this::clearScreen);
        widgets.put(COMPLETE_PREFIX, this::completePrefix);
        widgets.put(COMPLETE_WORD, this::completeWord);
        widgets.put(COPY_PREV_WORD, this::copyPrevWord);
        widgets.put(COPY_REGION_AS_KILL, this::copyRegionAsKill);
        widgets.put(DELETE_CHAR, this::deleteChar);
        widgets.put(DELETE_CHAR_OR_LIST, this::deleteCharOrList);
        widgets.put(DELETE_WORD, this::deleteWord);
        widgets.put(DIGIT_ARGUMENT, this::digitArgument);
        widgets.put(DO_LOWERCASE_VERSION, this::doLowercaseVersion);
        widgets.put(DOWN_CASE_WORD, this::downCaseWord);
        widgets.put(DOWN_LINE, this::downLine);
        widgets.put(DOWN_LINE_OR_HISTORY, this::downLineOrHistory);
        widgets.put(DOWN_LINE_OR_SEARCH, this::downLineOrSearch);
        widgets.put(DOWN_HISTORY, this::downHistory);
        widgets.put(EMACS_EDITING_MODE, this::emacsEditingMode);
        widgets.put(EMACS_BACKWARD_WORD, this::emacsBackwardWord);
        widgets.put(EMACS_FORWARD_WORD, this::emacsForwardWord);
        widgets.put(END_OF_BUFFER_OR_HISTORY, this::endOfBufferOrHistory);
        widgets.put(END_OF_HISTORY, this::endOfHistory);
        widgets.put(END_OF_LINE, this::endOfLine);
        widgets.put(END_OF_LINE_HIST, this::endOfLineHist);
        widgets.put(EXCHANGE_POINT_AND_MARK, this::exchangePointAndMark);
        widgets.put(EXPAND_HISTORY, this::expandHistory);
        widgets.put(EXPAND_OR_COMPLETE, this::expandOrComplete);
        widgets.put(EXPAND_OR_COMPLETE_PREFIX, this::expandOrCompletePrefix);
        widgets.put(EXPAND_WORD, this::expandWord);
        widgets.put(FRESH_LINE, this::freshLine);
        widgets.put(FORWARD_CHAR, this::forwardChar);
        widgets.put(FORWARD_WORD, this::forwardWord);
        widgets.put(HISTORY_INCREMENTAL_SEARCH_BACKWARD, this::historyIncrementalSearchBackward);
        widgets.put(HISTORY_INCREMENTAL_SEARCH_FORWARD, this::historyIncrementalSearchForward);
        widgets.put(HISTORY_SEARCH_BACKWARD, this::historySearchBackward);
        widgets.put(HISTORY_SEARCH_FORWARD, this::historySearchForward);
        widgets.put(INSERT_CLOSE_CURLY, this::insertCloseCurly);
        widgets.put(INSERT_CLOSE_PAREN, this::insertCloseParen);
        widgets.put(INSERT_CLOSE_SQUARE, this::insertCloseSquare);
        widgets.put(INSERT_COMMENT, this::insertComment);
        widgets.put(KILL_BUFFER, this::killBuffer);
        widgets.put(KILL_LINE, this::killLine);
        widgets.put(KILL_REGION, this::killRegion);
        widgets.put(KILL_WHOLE_LINE, this::killWholeLine);
        widgets.put(KILL_WORD, this::killWord);
        widgets.put(LIST_CHOICES, this::listChoices);
        widgets.put(MENU_COMPLETE, this::menuComplete);
        widgets.put(MENU_EXPAND_OR_COMPLETE, this::menuExpandOrComplete);
        widgets.put(NEG_ARGUMENT, this::negArgument);
        widgets.put(OVERWRITE_MODE, this::overwriteMode);
//        widgets.put(QUIT, this::quit);
        widgets.put(QUOTED_INSERT, this::quotedInsert);
        widgets.put(REDISPLAY, this::redisplay);
        widgets.put(REDRAW_LINE, this::redrawLine);
        widgets.put(REDO, this::redo);
        widgets.put(SELF_INSERT, this::selfInsert);
        widgets.put(SELF_INSERT_UNMETA, this::selfInsertUnmeta);
        widgets.put(SEND_BREAK, this::sendBreak);
        widgets.put(SET_MARK_COMMAND, this::setMarkCommand);
        widgets.put(TRANSPOSE_CHARS, this::transposeChars);
        widgets.put(TRANSPOSE_WORDS, this::transposeWords);
        widgets.put(UNDEFINED_KEY, this::undefinedKey);
        widgets.put(UNIVERSAL_ARGUMENT, this::universalArgument);
        widgets.put(UNDO, this::undo);
        widgets.put(UP_CASE_WORD, this::upCaseWord);
        widgets.put(UP_HISTORY, this::upHistory);
        widgets.put(UP_LINE, this::upLine);
        widgets.put(UP_LINE_OR_HISTORY, this::upLineOrHistory);
        widgets.put(UP_LINE_OR_SEARCH, this::upLineOrSearch);
        widgets.put(VI_ADD_EOL, this::viAddEol);
        widgets.put(VI_ADD_NEXT, this::viAddNext);
        widgets.put(VI_BACKWARD_CHAR, this::viBackwardChar);
        widgets.put(VI_BACKWARD_DELETE_CHAR, this::viBackwardDeleteChar);
        widgets.put(VI_BACKWARD_BLANK_WORD, this::viBackwardBlankWord);
        widgets.put(VI_BACKWARD_BLANK_WORD_END, this::viBackwardBlankWordEnd);
        widgets.put(VI_BACKWARD_KILL_WORD, this::viBackwardKillWord);
        widgets.put(VI_BACKWARD_WORD, this::viBackwardWord);
        widgets.put(VI_BACKWARD_WORD_END, this::viBackwardWordEnd);
        widgets.put(VI_BEGINNING_OF_LINE, this::viBeginningOfLine);
        widgets.put(VI_CMD_MODE, this::viCmdMode);
        widgets.put(VI_DIGIT_OR_BEGINNING_OF_LINE, this::viDigitOrBeginningOfLine);
        widgets.put(VI_DOWN_LINE_OR_HISTORY, this::viDownLineOrHistory);
        widgets.put(VI_CHANGE, this::viChange);
        widgets.put(VI_CHANGE_EOL, this::viChangeEol);
        widgets.put(VI_CHANGE_WHOLE_LINE, this::viChangeWholeLine);
        widgets.put(VI_DELETE_CHAR, this::viDeleteChar);
        widgets.put(VI_DELETE, this::viDelete);
        widgets.put(VI_END_OF_LINE, this::viEndOfLine);
        widgets.put(VI_KILL_EOL, this::viKillEol);
        widgets.put(VI_FIRST_NON_BLANK, this::viFirstNonBlank);
        widgets.put(VI_FIND_NEXT_CHAR, this::viFindNextChar);
        widgets.put(VI_FIND_NEXT_CHAR_SKIP, this::viFindNextCharSkip);
        widgets.put(VI_FIND_PREV_CHAR, this::viFindPrevChar);
        widgets.put(VI_FIND_PREV_CHAR_SKIP, this::viFindPrevCharSkip);
        widgets.put(VI_FORWARD_BLANK_WORD, this::viForwardBlankWord);
        widgets.put(VI_FORWARD_BLANK_WORD_END, this::viForwardBlankWordEnd);
        widgets.put(VI_FORWARD_CHAR, this::viForwardChar);
        widgets.put(VI_FORWARD_WORD, this::viForwardWord);
        widgets.put(VI_FORWARD_WORD, this::viForwardWord);
        widgets.put(VI_FORWARD_WORD_END, this::viForwardWordEnd);
        widgets.put(VI_HISTORY_SEARCH_BACKWARD, this::viHistorySearchBackward);
        widgets.put(VI_HISTORY_SEARCH_FORWARD, this::viHistorySearchForward);
        widgets.put(VI_INSERT, this::viInsert);
        widgets.put(VI_INSERT_BOL, this::viInsertBol);
        widgets.put(VI_INSERT_COMMENT, this::viInsertComment);
        widgets.put(VI_JOIN, this::viJoin);
        widgets.put(VI_KILL_LINE, this::viKillWholeLine);
        widgets.put(VI_MATCH_BRACKET, this::viMatchBracket);
        widgets.put(VI_OPEN_LINE_ABOVE, this::viOpenLineAbove);
        widgets.put(VI_OPEN_LINE_BELOW, this::viOpenLineBelow);
        widgets.put(VI_PUT_AFTER, this::viPutAfter);
        widgets.put(VI_PUT_BEFORE, this::viPutBefore);
        widgets.put(VI_REPEAT_FIND, this::viRepeatFind);
        widgets.put(VI_REPEAT_SEARCH, this::viRepeatSearch);
        widgets.put(VI_REPLACE_CHARS, this::viReplaceChars);
        widgets.put(VI_REV_REPEAT_FIND, this::viRevRepeatFind);
        widgets.put(VI_REV_REPEAT_SEARCH, this::viRevRepeatSearch);
        widgets.put(VI_SWAP_CASE, this::viSwapCase);
        widgets.put(VI_UP_LINE_OR_HISTORY, this::viUpLineOrHistory);
        widgets.put(VI_YANK, this::viYankTo);
        widgets.put(VI_YANK_WHOLE_LINE, this::viYankWholeLine);
        widgets.put(VISUAL_LINE_MODE, this::visualLineMode);
        widgets.put(VISUAL_MODE, this::visualMode);
        widgets.put(WHAT_CURSOR_POSITION, this::whatCursorPosition);
        widgets.put(YANK, this::yank);
        widgets.put(YANK_POP, this::yankPop);
        widgets.put(MOUSE, this::mouse);
        widgets.put(BEGIN_PASTE, this::beginPaste);
        widgets.put(FOCUS_IN, this::focusIn);
        widgets.put(FOCUS_OUT, this::focusOut);
        return widgets;
    }

    public boolean redisplay() {
        redisplay(true);
        return true;
    }

    protected synchronized void redisplay(boolean flush) {
        if (skipRedisplay) {
            skipRedisplay = false;
            return;
        }

        Status status = Status.getStatus(terminal, false);
        if (status != null) {
            status.redraw();
        }

        if (size.getRows() > 0 && size.getRows() < MIN_ROWS) {
            AttributedStringBuilder sb = new AttributedStringBuilder().tabs(TAB_WIDTH);

            sb.append(prompt);
            concat(getHighlightedBuffer(buf.toString()).columnSplitLength(Integer.MAX_VALUE), sb);
            AttributedString full = sb.toAttributedString();

            sb.setLength(0);
            sb.append(prompt);
            String line = buf.upToCursor();
            if(maskingCallback != null) {
                line = maskingCallback.display(line);
            }

            concat(new AttributedString(line).columnSplitLength(Integer.MAX_VALUE), sb);
            AttributedString toCursor = sb.toAttributedString();

            int w = WCWidth.wcwidth('\u2026');
            int width = size.getColumns();
            int cursor = toCursor.columnLength();
            int inc = width /2 + 1;
            while (cursor <= smallTerminalOffset + w) {
                smallTerminalOffset -= inc;
            }
            while (cursor >= smallTerminalOffset + width - w) {
                smallTerminalOffset += inc;
            }
            if (smallTerminalOffset > 0) {
                sb.setLength(0);
                sb.append("\u2026");
                sb.append(full.columnSubSequence(smallTerminalOffset + w, Integer.MAX_VALUE));
                full = sb.toAttributedString();
            }
            int length = full.columnLength();
            if (length >= smallTerminalOffset + width) {
                sb.setLength(0);
                sb.append(full.columnSubSequence(0, width - w));
                sb.append("\u2026");
                full = sb.toAttributedString();
            }

            display.update(Collections.singletonList(full), cursor - smallTerminalOffset, flush);
            return;
        }

        List<AttributedString> secondaryPrompts = new ArrayList<>();
        AttributedString full = getDisplayedBufferWithPrompts(secondaryPrompts);

        List<AttributedString> newLines;
        if (size.getColumns() <= 0) {
            newLines = new ArrayList<>();
            newLines.add(full);
        } else {
            newLines = full.columnSplitLength(size.getColumns(), true, display.delayLineWrap());
        }

        List<AttributedString> rightPromptLines;
        if (rightPrompt.length() == 0 || size.getColumns() <= 0) {
            rightPromptLines = new ArrayList<>();
        } else {
            rightPromptLines = rightPrompt.columnSplitLength(size.getColumns());
        }
        while (newLines.size() < rightPromptLines.size()) {
            newLines.add(new AttributedString(""));
        }
        for (int i = 0; i < rightPromptLines.size(); i++) {
            AttributedString line = rightPromptLines.get(i);
            newLines.set(i, addRightPrompt(line, newLines.get(i)));
        }

        int cursorPos = -1;
        if (size.getColumns() > 0) {
            AttributedStringBuilder sb = new AttributedStringBuilder().tabs(TAB_WIDTH);
            sb.append(prompt);
            String buffer = buf.upToCursor();
            if (maskingCallback != null) {
                buffer = maskingCallback.display(buffer);
            }
            sb.append(insertSecondaryPrompts(new AttributedString(buffer), secondaryPrompts, false));
            List<AttributedString> promptLines = sb.columnSplitLength(size.getColumns(), false, display.delayLineWrap());
            if (!promptLines.isEmpty()) {
                cursorPos = size.cursorPos(promptLines.size() - 1,
                                           promptLines.get(promptLines.size() - 1).columnLength());
            }
        }

        display.update(newLines, cursorPos, flush);
    }

    private void concat(List<AttributedString> lines, AttributedStringBuilder sb) {
        if (lines.size() > 1) {
            for (int i = 0; i < lines.size() - 1; i++) {
                sb.append(lines.get(i));
                sb.style(sb.style().inverse());
                sb.append("\\n");
                sb.style(sb.style().inverseOff());
            }
        }
        sb.append(lines.get(lines.size() - 1));
    }

    
Compute the full string to be displayed with the left, right and secondary prompts
Params:
secondaryPrompts – a list to store the secondary prompts
Returns:
the displayed string including the buffer, left prompts and the help below/**
     * Compute the full string to be displayed with the left, right and secondary prompts
     * @param secondaryPrompts a list to store the secondary prompts
     * @return the displayed string including the buffer, left prompts and the help below
     */
    public AttributedString getDisplayedBufferWithPrompts(List<AttributedString> secondaryPrompts) {
        AttributedString attBuf = getHighlightedBuffer(buf.toString());

        AttributedString tNewBuf = insertSecondaryPrompts(attBuf, secondaryPrompts);
        AttributedStringBuilder full = new AttributedStringBuilder().tabs(TAB_WIDTH);
        full.append(prompt);
        full.append(tNewBuf);
        if (post != null) {
            full.append("\n");
            full.append(post.get());
        }
        return full.toAttributedString();
    }

    private AttributedString getHighlightedBuffer(String buffer) {
        if (maskingCallback != null) {
            buffer = maskingCallback.display(buffer);
        }
        if (highlighter != null && !isSet(Option.DISABLE_HIGHLIGHTER)) {
            return highlighter.highlight(this, buffer);
        }
        return new AttributedString(buffer);
    }

    private AttributedString expandPromptPattern(String pattern, int padToWidth,
                                                 String message, int line) {
        ArrayList<AttributedString> parts = new ArrayList<>();
        boolean isHidden = false;
        int padPartIndex = -1;
        StringBuilder padPartString = null;
        StringBuilder sb = new StringBuilder();
        // Add "%{" to avoid special case for end of string.
        pattern = pattern + "%{";
        int plen = pattern.length();
        int padChar = -1;
        int padPos = -1;
        int cols = 0;
        for (int i = 0; i < plen; ) {
            char ch = pattern.charAt(i++);
            if (ch == '%' && i < plen) {
                int count = 0;
                boolean countSeen = false;
                decode: while (true) {
                    ch = pattern.charAt(i++);
                    switch (ch) {
                       case '{':
                       case '}':
                           String str = sb.toString();
                           AttributedString astr;
                           if (!isHidden) {
                               astr = AttributedString.fromAnsi(str);
                               cols += astr.columnLength();
                           } else {
                               astr = new AttributedString(str, AttributedStyle.HIDDEN);
                           }
                           if (padPartIndex == parts.size()) {
                               padPartString = sb;
                               if (i < plen) {
                                   sb = new StringBuilder();
                               }
                           } else {
                               sb.setLength(0);
                           }
                           parts.add(astr);
                           isHidden = ch == '{';
                            break decode;
                        case '%':
                            sb.append(ch);
                            break decode;
                        case 'N':
                            sb.append(getInt(LINE_OFFSET, 0) + line);
                            break decode;
                        case 'M':
                            if (message != null)
                                sb.append(message);
                            break decode;
                        case 'P':
                            if (countSeen && count >= 0)
                                padToWidth = count;
                            if (i < plen) {
                                padChar = pattern.charAt(i++);
                                // FIXME check surrogate
                            }
                            padPos = sb.length();
                            padPartIndex = parts.size();
                            break decode;
                        case '-':
                        case '0':
                        case '1':
                        case '2':
                        case '3':
                        case '4':
                        case '5':
                        case '6':
                        case '7':
                        case '8':
                        case '9':
                            boolean neg = false;
                            if (ch == '-') {
                                neg = true;
                                ch = pattern.charAt(i++);
                            }
                            countSeen = true;
                            count = 0;
                            while (ch >= '0' && ch <= '9') {
                                count = (count < 0 ? 0 : 10 * count) + (ch - '0');
                                ch = pattern.charAt(i++);
                            }
                            if (neg) {
                                count = -count;
                            }
                            i--;
                            break;
                        default:
                            break decode;
                    }
                }
            } else
                sb.append(ch);
        }
        if (padToWidth > cols) {
            int padCharCols = WCWidth.wcwidth(padChar);
            int padCount = (padToWidth - cols) / padCharCols;
            sb = padPartString;
            while (--padCount >= 0)
                sb.insert(padPos, (char) padChar); // FIXME if wide
            parts.set(padPartIndex, AttributedString.fromAnsi(sb.toString()));
        }
        return AttributedString.join(null, parts);
    }

    private AttributedString insertSecondaryPrompts(AttributedString str, List<AttributedString> prompts) {
        return insertSecondaryPrompts(str, prompts, true);
    }

    private AttributedString insertSecondaryPrompts(AttributedString strAtt, List<AttributedString> prompts, boolean computePrompts) {
        Objects.requireNonNull(prompts);
        List<AttributedString> lines = strAtt.columnSplitLength(Integer.MAX_VALUE);
        AttributedStringBuilder sb = new AttributedStringBuilder();
        String secondaryPromptPattern = getString(SECONDARY_PROMPT_PATTERN, DEFAULT_SECONDARY_PROMPT_PATTERN);
        boolean needsMessage = secondaryPromptPattern.contains("%M");
        AttributedStringBuilder buf = new AttributedStringBuilder();
        int width = 0;
        List<String> missings = new ArrayList<>();
        if (computePrompts && secondaryPromptPattern.contains("%P")) {
            width = prompt.columnLength();
            for (int line = 0; line < lines.size() - 1; line++) {
                AttributedString prompt;
                buf.append(lines.get(line)).append("\n");
                String missing = "";
                if (needsMessage) {
                    try {
                        parser.parse(buf.toString(), buf.length(), ParseContext.SECONDARY_PROMPT);
                    } catch (EOFError e) {
                        missing = e.getMissing();
                    } catch (SyntaxError e) {
                        // Ignore
                    }
                }
                missings.add(missing);
                prompt = expandPromptPattern(secondaryPromptPattern, 0, missing, line + 1);
                width = Math.max(width, prompt.columnLength());
            }
            buf.setLength(0);
        }
        int line = 0;
        while (line < lines.size() - 1) {
            sb.append(lines.get(line)).append("\n");
            buf.append(lines.get(line)).append("\n");
            AttributedString prompt;
            if (computePrompts) {
                String missing = "";
                if (needsMessage) {
                    if (missings.isEmpty()) {
                        try {
                            parser.parse(buf.toString(), buf.length(), ParseContext.SECONDARY_PROMPT);
                        } catch (EOFError e) {
                            missing = e.getMissing();
                        } catch (SyntaxError e) {
                            // Ignore
                        }
                    } else {
                        missing = missings.get(line);
                    }
                }
                prompt = expandPromptPattern(secondaryPromptPattern, width, missing, line + 1);
            } else {
                prompt = prompts.get(line);
            }
            prompts.add(prompt);
            sb.append(prompt);
            line++;
        }
        sb.append(lines.get(line));
        buf.append(lines.get(line));
        return sb.toAttributedString();
    }

    private AttributedString addRightPrompt(AttributedString prompt, AttributedString line) {
        int width = prompt.columnLength();
        boolean endsWithNl = line.length() > 0
            && line.charAt(line.length() - 1) == '\n';
        // columnLength counts -1 for the final newline; adjust for that
        int nb = size.getColumns() - width
            - (line.columnLength() + (endsWithNl ? 1 : 0));
        if (nb >= 3) {
            AttributedStringBuilder sb = new AttributedStringBuilder(size.getColumns());
            sb.append(line, 0, endsWithNl ? line.length() - 1 : line.length());
            for (int j = 0; j < nb; j++) {
                sb.append(' ');
            }
            sb.append(prompt);
            if (endsWithNl) {
                sb.append('\n');
            }
            line = sb.toAttributedString();
        }
        return line;
    }

    //
    // Completion
    //

    protected boolean insertTab() {
        return isSet(Option.INSERT_TAB)
                    && getLastBinding().equals("\t")
                    && buf.toString().matches("(^|[\\s\\S]*\n)[\r\n\t ]*");
    }

    protected boolean expandHistory() {
        String str = buf.toString();
        String exp = expander.expandHistory(history, str);
        if (!exp.equals(str)) {
            buf.clear();
            buf.write(exp);
            return true;
        } else {
            return false;
        }
    }

    protected enum CompletionType {
        Expand,
        ExpandComplete,
        Complete,
        List,
    }

    protected boolean expandWord() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.Expand, isSet(Option.MENU_COMPLETE), false);
        }
    }

    protected boolean expandOrComplete() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.ExpandComplete, isSet(Option.MENU_COMPLETE), false);
        }
    }

    protected boolean expandOrCompletePrefix() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.ExpandComplete, isSet(Option.MENU_COMPLETE), true);
        }
    }

    protected boolean completeWord() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.Complete, isSet(Option.MENU_COMPLETE), false);
        }
    }

    protected boolean menuComplete() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.Complete, true, false);
        }
    }

    protected boolean menuExpandOrComplete() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.ExpandComplete, true, false);
        }
    }

    protected boolean completePrefix() {
        if (insertTab()) {
            return selfInsert();
        } else {
            return doComplete(CompletionType.Complete, isSet(Option.MENU_COMPLETE), true);
        }
    }

    protected boolean listChoices() {
        return doComplete(CompletionType.List, isSet(Option.MENU_COMPLETE), false);
    }

    protected boolean deleteCharOrList() {
        if (buf.cursor() != buf.length() || buf.length() == 0) {
            return deleteChar();
        } else {
            return doComplete(CompletionType.List, isSet(Option.MENU_COMPLETE), false);
        }
    }

    protected boolean doComplete(CompletionType lst, boolean useMenu, boolean prefix) {
        // If completion is disabled, just bail out
        if (getBoolean(DISABLE_COMPLETION, false)) {
            return true;
        }
        // Try to expand history first
        // If there is actually an expansion, bail out now
        if (!isSet(Option.DISABLE_EVENT_EXPANSION)) {
            try {
                if (expandHistory()) {
                    return true;
                }
            } catch (Exception e) {
                Log.info("Error while expanding history", e);
                return false;
            }
        }

        // Parse the command line
        CompletingParsedLine line;
        try {
            line = wrap(parser.parse(buf.toString(), buf.cursor(), ParseContext.COMPLETE));
        } catch (Exception e) {
            Log.info("Error while parsing line", e);
            return false;
        }

        // Find completion candidates
        List<Candidate> candidates = new ArrayList<>();
        try {
            if (completer != null) {
                completer.complete(this, line, candidates);
            }
        } catch (Exception e) {
            Log.info("Error while finding completion candidates", e);
            return false;
        }

        if (lst == CompletionType.ExpandComplete || lst == CompletionType.Expand) {
            String w = expander.expandVar(line.word());
            if (!line.word().equals(w)) {
                if (prefix) {
                    buf.backspace(line.wordCursor());
                } else {
                    buf.move(line.word().length() - line.wordCursor());
                    buf.backspace(line.word().length());
                }
                buf.write(w);
                return true;
            }
            if (lst == CompletionType.Expand) {
                return false;
            } else {
                lst = CompletionType.Complete;
            }
        }

        boolean caseInsensitive = isSet(Option.CASE_INSENSITIVE);
        int errors = getInt(ERRORS, DEFAULT_ERRORS);

        // Build a list of sorted candidates
        Map<String, List<Candidate>> sortedCandidates = new HashMap<>();
        for (Candidate cand : candidates) {
            sortedCandidates
                    .computeIfAbsent(AttributedString.fromAnsi(cand.value()).toString(), s -> new ArrayList<>())
                    .add(cand);
        }

        // Find matchers
        // TODO: glob completion
        List<Function<Map<String, List<Candidate>>,
                      Map<String, List<Candidate>>>> matchers;
        Predicate<String> exact;
        if (prefix) {
            String wd = line.word();
            String wdi = caseInsensitive ? wd.toLowerCase() : wd;
            String wp = wdi.substring(0, line.wordCursor());
            matchers = Arrays.asList(
                    simpleMatcher(s -> (caseInsensitive ? s.toLowerCase() : s).startsWith(wp)),
                    simpleMatcher(s -> (caseInsensitive ? s.toLowerCase() : s).contains(wp)),
                    typoMatcher(wp, errors, caseInsensitive)
            );
            exact = s -> caseInsensitive ? s.equalsIgnoreCase(wp) : s.equals(wp);
        } else if (isSet(Option.COMPLETE_IN_WORD)) {
            String wd = line.word();
            String wdi = caseInsensitive ? wd.toLowerCase() : wd;
            String wp = wdi.substring(0, line.wordCursor());
            String ws = wdi.substring(line.wordCursor());
            Pattern p1 = Pattern.compile(Pattern.quote(wp) + ".*" + Pattern.quote(ws) + ".*");
            Pattern p2 = Pattern.compile(".*" + Pattern.quote(wp) + ".*" + Pattern.quote(ws) + ".*");
            matchers = Arrays.asList(
                    simpleMatcher(s -> p1.matcher(caseInsensitive ? s.toLowerCase() : s).matches()),
                    simpleMatcher(s -> p2.matcher(caseInsensitive ? s.toLowerCase() : s).matches()),
                    typoMatcher(wdi, errors, caseInsensitive)
            );
            exact = s -> caseInsensitive ? s.equalsIgnoreCase(wd) : s.equals(wd);
        } else {
            String wd = line.word();
            String wdi = caseInsensitive ? wd.toLowerCase() : wd;
            matchers = Arrays.asList(
                    simpleMatcher(s -> (caseInsensitive ? s.toLowerCase() : s).startsWith(wdi)),
                    simpleMatcher(s -> (caseInsensitive ? s.toLowerCase() : s).contains(wdi)),
                    typoMatcher(wdi, errors, caseInsensitive)
            );
            exact = s -> caseInsensitive ? s.equalsIgnoreCase(wd) : s.equals(wd);
        }
        // Find matching candidates
        Map<String, List<Candidate>> matching = Collections.emptyMap();
        for (Function<Map<String, List<Candidate>>,
                      Map<String, List<Candidate>>> matcher : matchers) {
            matching = matcher.apply(sortedCandidates);
            if (!matching.isEmpty()) {
                break;
            }
        }

        // If we have no matches, bail out
        if (matching.isEmpty()) {
            return false;
        }

        // If we only need to display the list, do it now
        if (lst == CompletionType.List) {
            List<Candidate> possible = matching.entrySet().stream()
                    .flatMap(e -> e.getValue().stream())
                    .collect(Collectors.toList());
            doList(possible, line.word(), false, line::escape);
            return !possible.isEmpty();
        }

        // Check if there's a single possible match
        Candidate completion = null;
        // If there's a single possible completion
        if (matching.size() == 1) {
            completion = matching.values().stream().flatMap(Collection::stream)
                    .findFirst().orElse(null);
        }
        // Or if RECOGNIZE_EXACT is set, try to find an exact match
        else if (isSet(Option.RECOGNIZE_EXACT)) {
            completion = matching.values().stream().flatMap(Collection::stream)
                    .filter(Candidate::complete)
                    .filter(c -> exact.test(c.value()))
                    .findFirst().orElse(null);
        }
        // Complete and exit
        if (completion != null && !completion.value().isEmpty()) {
            if (prefix) {
                buf.backspace(line.rawWordCursor());
            } else {
                buf.move(line.rawWordLength() - line.rawWordCursor());
                buf.backspace(line.rawWordLength());
            }
            buf.write(line.escape(completion.value(), completion.complete()));
            if (completion.complete()) {
                if (buf.currChar() != ' ') {
                    buf.write(" ");
                } else {
                    buf.move(1);
                }
            }
            if (completion.suffix() != null) {
                redisplay();
                Binding op = readBinding(getKeys());
                if (op != null) {
                    String chars = getString(REMOVE_SUFFIX_CHARS, DEFAULT_REMOVE_SUFFIX_CHARS);
                    String ref = op instanceof Reference ? ((Reference) op).name() : null;
                    if (SELF_INSERT.equals(ref) && chars.indexOf(getLastBinding().charAt(0)) >= 0
                            || ACCEPT_LINE.equals(ref)) {
                        buf.backspace(completion.suffix().length());
                        if (getLastBinding().charAt(0) != ' ') {
                            buf.write(' ');
                        }
                    }
                    pushBackBinding(true);
                }
            }
            return true;
        }

        List<Candidate> possible = matching.entrySet().stream()
                .flatMap(e -> e.getValue().stream())
                .collect(Collectors.toList());

        if (useMenu) {
            buf.move(line.word().length() - line.wordCursor());
            buf.backspace(line.word().length());
            doMenu(possible, line.word(), line::escape);
            return true;
        }

        // Find current word and move to end
        String current;
        if (prefix) {
            current = line.word().substring(0, line.wordCursor());
        } else {
            current = line.word();
            buf.move(line.rawWordLength() - line.rawWordCursor());
        }
        // Now, we need to find the unambiguous completion
        // TODO: need to find common suffix
        String commonPrefix = null;
        for (String key : matching.keySet()) {
            commonPrefix = commonPrefix == null ? key : getCommonStart(commonPrefix, key, caseInsensitive);
        }
        boolean hasUnambiguous = commonPrefix.startsWith(current) && !commonPrefix.equals(current);

        if (hasUnambiguous) {
            buf.backspace(line.rawWordLength());
            buf.write(line.escape(commonPrefix, false));
            current = commonPrefix;
            if ((!isSet(Option.AUTO_LIST) && isSet(Option.AUTO_MENU))
                    || (isSet(Option.AUTO_LIST) && isSet(Option.LIST_AMBIGUOUS))) {
                if (!nextBindingIsComplete()) {
                    return true;
                }
            }
        }
        if (isSet(Option.AUTO_LIST)) {
            if (!doList(possible, current, true, line::escape)) {
                return true;
            }
        }
        if (isSet(Option.AUTO_MENU)) {
            buf.backspace(current.length());
            doMenu(possible, line.word(), line::escape);
        }
        return true;
    }

    private CompletingParsedLine wrap(ParsedLine line) {
        if (line instanceof CompletingParsedLine) {
            return (CompletingParsedLine) line;
        } else {
            return new CompletingParsedLine() {
                public String word() {
                    return line.word();
                }
                public int wordCursor() {
                    return line.wordCursor();
                }
                public int wordIndex() {
                    return line.wordIndex();
                }
                public List<String> words() {
                    return line.words();
                }
                public String line() {
                    return line.line();
                }
                public int cursor() {
                    return line.cursor();
                }
                public CharSequence escape(CharSequence candidate, boolean complete) {
                    return candidate;
                }
                public int rawWordCursor() {
                    return wordCursor();
                }
                public int rawWordLength() {
                    return word().length();
                }
            };
        }
    }

    protected Comparator<Candidate> getCandidateComparator(boolean caseInsensitive, String word) {
        String wdi = caseInsensitive ? word.toLowerCase() : word;
        ToIntFunction<String> wordDistance = w -> distance(wdi, caseInsensitive ? w.toLowerCase() : w);
        return Comparator
                .comparing(Candidate::value, Comparator.comparingInt(wordDistance))
                .thenComparing(Candidate::value, Comparator.comparingInt(String::length))
                .thenComparing(Comparator.naturalOrder());
    }

    protected String getOthersGroupName() {
        return getString(OTHERS_GROUP_NAME, DEFAULT_OTHERS_GROUP_NAME);
    }

    protected String getOriginalGroupName() {
        return getString(ORIGINAL_GROUP_NAME, DEFAULT_ORIGINAL_GROUP_NAME);
    }


    protected Comparator<String> getGroupComparator() {
        return Comparator.<String>comparingInt(s -> getOthersGroupName().equals(s) ? 1 : getOriginalGroupName().equals(s) ? -1 : 0)
                .thenComparing(String::toLowerCase, Comparator.naturalOrder());
    }

    private void mergeCandidates(List<Candidate> possible) {
        // Merge candidates if the have the same key
        Map<String, List<Candidate>> keyedCandidates = new HashMap<>();
        for (Candidate candidate : possible) {
            if (candidate.key() != null) {
                List<Candidate> cands = keyedCandidates.computeIfAbsent(candidate.key(), s -> new ArrayList<>());
                cands.add(candidate);
            }
        }
        if (!keyedCandidates.isEmpty()) {
            for (List<Candidate> candidates : keyedCandidates.values()) {
                if (candidates.size() >= 1) {
                    possible.removeAll(candidates);
                    // Candidates with the same key are supposed to have
                    // the same description
                    candidates.sort(Comparator.comparing(Candidate::value));
                    Candidate first = candidates.get(0);
                    String disp = candidates.stream()
                            .map(Candidate::displ)
                            .collect(Collectors.joining(" "));
                    possible.add(new Candidate(first.value(), disp, first.group(),
                            first.descr(), first.suffix(), null, first.complete()));
                }
            }
        }
    }

    private Function<Map<String, List<Candidate>>,
                     Map<String, List<Candidate>>> simpleMatcher(Predicate<String> pred) {
        return m -> m.entrySet().stream()
                .filter(e -> pred.test(e.getKey()))
                .collect(Collectors.toMap(Entry::getKey, Entry::getValue));
    }

    private Function<Map<String, List<Candidate>>,
                     Map<String, List<Candidate>>> typoMatcher(String word, int errors, boolean caseInsensitive) {
        return m -> {
            Map<String, List<Candidate>> map = m.entrySet().stream()
                    .filter(e -> distance(word, caseInsensitive ? e.getKey() : e.getKey().toLowerCase()) < errors)
                    .collect(Collectors.toMap(Entry::getKey, Entry::getValue));
            if (map.size() > 1) {
                map.computeIfAbsent(word, w -> new ArrayList<>())
                        .add(new Candidate(word, word, getOriginalGroupName(), null, null, null, false));
            }
            return map;
        };
    }

    private int distance(String word, String cand) {
        if (word.length() < cand.length()) {
            int d1 = Levenshtein.distance(word, cand.substring(0, Math.min(cand.length(), word.length())));
            int d2 = Levenshtein.distance(word, cand);
            return Math.min(d1, d2);
        } else {
            return Levenshtein.distance(word, cand);
        }
    }

    protected boolean nextBindingIsComplete() {
        redisplay();
        KeyMap<Binding> keyMap = keyMaps.get(MENU);
        Binding operation = readBinding(getKeys(), keyMap);
        if (operation instanceof Reference && MENU_COMPLETE.equals(((Reference) operation).name())) {
            return true;
        } else {
            pushBackBinding();
            return false;
        }
    }

    private class MenuSupport implements Supplier<AttributedString> {
        final List<Candidate> possible;
        final BiFunction<CharSequence, Boolean, CharSequence> escaper;
        int selection;
        int topLine;
        String word;
        AttributedString computed;
        int lines;
        int columns;
        String completed;

        public MenuSupport(List<Candidate> original, String completed, BiFunction<CharSequence, Boolean, CharSequence> escaper) {
            this.possible = new ArrayList<>();
            this.escaper = escaper;
            this.selection = -1;
            this.topLine = 0;
            this.word = "";
            this.completed = completed;
            computePost(original, null, possible, completed);
            next();
        }

        public Candidate completion() {
            return possible.get(selection);
        }

        public void next() {
            selection = (selection + 1) % possible.size();
            update();
        }

        public void previous() {
            selection = (selection + possible.size() - 1) % possible.size();
            update();
        }

        
Move 'step' options along the major axis of the menu.

ie. if the menu is listing rows first, change row (up/down);
otherwise move column (left/right)
Params:
step – number of options to move by/**
         * Move 'step' options along the major axis of the menu.<p>
         * ie. if the menu is listing rows first, change row (up/down);
         * otherwise move column (left/right)
         *
         * @param step number of options to move by
         */
        private void major(int step) {
            int axis = isSet(Option.LIST_ROWS_FIRST) ? columns : lines;
            int sel = selection + step * axis;
            if (sel < 0) {
                int pos = (sel + axis) % axis; // needs +axis as (-1)%x == -1
                int remainders = possible.size() % axis;
                sel = possible.size() - remainders + pos;
                if (sel >= possible.size()) {
                    sel -= axis;
                }
            } else if (sel >= possible.size()) {
                sel = sel % axis;
            }
            selection = sel;
            update();
        }

        
Move 'step' options along the minor axis of the menu.

ie. if the menu is listing rows first, move along the row (left/right);
otherwise move along the column (up/down)
Params:
step – number of options to move by/**
         * Move 'step' options along the minor axis of the menu.<p>
         * ie. if the menu is listing rows first, move along the row (left/right);
         * otherwise move along the column (up/down)
         *
         * @param step number of options to move by
         */
        private void minor(int step) {
            int axis = isSet(Option.LIST_ROWS_FIRST) ? columns : lines;
            int row = selection % axis;
            int options = possible.size();
            if (selection - row + axis > options) {
                // selection is the last row/column
                // so there are fewer options than other rows
                axis = options%axis;
            }
            selection = selection - row + ((axis + row + step) % axis);
            update();
        }

        public void up() {
            if (isSet(Option.LIST_ROWS_FIRST)) {
                major(-1);
            } else {
                minor(-1);
            }
        }

        public void down() {
            if (isSet(Option.LIST_ROWS_FIRST)) {
                major(1);
            } else {
                minor(1);
            }
        }

        public void left() {
            if (isSet(Option.LIST_ROWS_FIRST)) {
                minor(-1);
            } else {
                major(-1);
            }
        }

        public void right() {
            if (isSet(Option.LIST_ROWS_FIRST)) {
                minor(1);
            } else {
                major(1);
            }
        }

        private void update() {
            buf.backspace(word.length());
            word = escaper.apply(completion().value(), true).toString();
            buf.write(word);

            // Compute displayed prompt
            PostResult pr = computePost(possible, completion(), null, completed);
            AttributedString text = insertSecondaryPrompts(AttributedStringBuilder.append(prompt, buf.toString()), new ArrayList<>());
            int promptLines = text.columnSplitLength(size.getColumns(), false, display.delayLineWrap()).size();
            if (pr.lines > size.getRows() - promptLines) {
                int displayed = size.getRows() - promptLines - 1;
                if (pr.selectedLine >= 0) {
                    if (pr.selectedLine < topLine) {
                        topLine = pr.selectedLine;
                    } else if (pr.selectedLine >= topLine + displayed) {
                        topLine = pr.selectedLine - displayed + 1;
                    }
                }
                AttributedString post = pr.post;
                if (post.length() > 0 && post.charAt(post.length() - 1) != '\n') {
                    post = new AttributedStringBuilder(post.length() + 1)
                            .append(post).append("\n").toAttributedString();
                }
                List<AttributedString> lines = post.columnSplitLength(size.getColumns(), true, display.delayLineWrap());
                List<AttributedString> sub = new ArrayList<>(lines.subList(topLine, topLine + displayed));
                sub.add(new AttributedStringBuilder()
                        .style(AttributedStyle.DEFAULT.foreground(AttributedStyle.CYAN))
                        .append("rows ")
                        .append(Integer.toString(topLine + 1))
                        .append(" to ")
                        .append(Integer.toString(topLine + displayed))
                        .append(" of ")
                        .append(Integer.toString(lines.size()))
                        .append("\n")
                        .style(AttributedStyle.DEFAULT).toAttributedString());
                computed = AttributedString.join(AttributedString.EMPTY, sub);
            } else {
                computed = pr.post;
            }
            lines = pr.lines;
            columns = (possible.size() + lines - 1) / lines;
        }

        @Override
        public AttributedString get() {
            return computed;
        }

    }

    protected boolean doMenu(List<Candidate> original, String completed, BiFunction<CharSequence, Boolean, CharSequence> escaper) {
        // Reorder candidates according to display order
        final List<Candidate> possible = new ArrayList<>();
        boolean caseInsensitive = isSet(Option.CASE_INSENSITIVE);
        original.sort(getCandidateComparator(caseInsensitive, completed));
        mergeCandidates(original);
        computePost(original, null, possible, completed);

        // Build menu support
        MenuSupport menuSupport = new MenuSupport(original, completed, escaper);
        post = menuSupport;
        redisplay();

        // Loop
        KeyMap<Binding> keyMap = keyMaps.get(MENU);
        Binding operation;
        while ((operation = readBinding(getKeys(), keyMap)) != null) {
            String ref = (operation instanceof Reference) ? ((Reference) operation).name() : "";
            switch (ref) {
                case MENU_COMPLETE:
                    menuSupport.next();
                    break;
                case REVERSE_MENU_COMPLETE:
                    menuSupport.previous();
                    break;
                case UP_LINE_OR_HISTORY:
                case UP_LINE_OR_SEARCH:
                    menuSupport.up();
                    break;
                case DOWN_LINE_OR_HISTORY:
                case DOWN_LINE_OR_SEARCH:
                    menuSupport.down();
                    break;
                case FORWARD_CHAR:
                    menuSupport.right();
                    break;
                case BACKWARD_CHAR:
                    menuSupport.left();
                    break;
                case CLEAR_SCREEN:
                    clearScreen();
                    break;
                default: {
                    Candidate completion = menuSupport.completion();
                    if (completion.suffix() != null) {
                        String chars = getString(REMOVE_SUFFIX_CHARS, DEFAULT_REMOVE_SUFFIX_CHARS);
                        if (SELF_INSERT.equals(ref)
                                && chars.indexOf(getLastBinding().charAt(0)) >= 0
                                || BACKWARD_DELETE_CHAR.equals(ref)) {
                            buf.backspace(completion.suffix().length());
                        }
                    }
                    if (completion.complete()
                            && getLastBinding().charAt(0) != ' '
                            && (SELF_INSERT.equals(ref) || getLastBinding().charAt(0) != ' ')) {
                        buf.write(' ');
                    }
                    if (!ACCEPT_LINE.equals(ref)
                            && !(SELF_INSERT.equals(ref)
                                && completion.suffix() != null
                                && completion.suffix().startsWith(getLastBinding()))) {
                        pushBackBinding(true);
                    }
                    post = null;
                    return true;
                }
            }
            redisplay();
        }
        return false;
    }

    protected boolean doList(List<Candidate> possible, String completed, boolean runLoop, BiFunction<CharSequence, Boolean, CharSequence> escaper) {
        // If we list only and if there's a big
        // number of items, we should ask the user
        // for confirmation, display the list
        // and redraw the line at the bottom
        mergeCandidates(possible);
        AttributedString text = insertSecondaryPrompts(AttributedStringBuilder.append(prompt, buf.toString()), new ArrayList<>());
        int promptLines = text.columnSplitLength(size.getColumns(), false, display.delayLineWrap()).size();
        PostResult postResult = computePost(possible, null, null, completed);
        int lines = postResult.lines;
        int listMax = getInt(LIST_MAX, DEFAULT_LIST_MAX);
        if (listMax > 0 && possible.size() >= listMax
                || lines >= size.getRows() - promptLines) {
            // prompt
            post = () -> new AttributedString(getAppName() + ": do you wish to see to see all " + possible.size()
                    + " possibilities (" + lines + " lines)?");
            redisplay(true);
            int c = readCharacter();
            if (c != 'y' && c != 'Y' && c != '\t') {
                post = null;
                return false;
            }
        }

        boolean caseInsensitive = isSet(Option.CASE_INSENSITIVE);
        StringBuilder sb = new StringBuilder();
        while (true) {
            String current = completed + sb.toString();
            List<Candidate> cands;
            if (sb.length() > 0) {
                cands = possible.stream()
                        .filter(c -> caseInsensitive
                                    ? c.value().toLowerCase().startsWith(current.toLowerCase())
                                    : c.value().startsWith(current))
                        .sorted(getCandidateComparator(caseInsensitive, current))
                        .collect(Collectors.toList());
            } else {
                cands = possible.stream()
                        .sorted(getCandidateComparator(caseInsensitive, current))
                        .collect(Collectors.toList());
            }
            post = () -> {
                AttributedString t = insertSecondaryPrompts(AttributedStringBuilder.append(prompt, buf.toString()), new ArrayList<>());
                int pl = t.columnSplitLength(size.getColumns(), false, display.delayLineWrap()).size();
                PostResult pr = computePost(cands, null, null, current);
                if (pr.lines >= size.getRows() - pl) {
                    post = null;
                    int oldCursor = buf.cursor();
                    buf.cursor(buf.length());
                    redisplay(false);
                    buf.cursor(oldCursor);
                    println();
                    List<AttributedString> ls = postResult.post.columnSplitLength(size.getColumns(), false, display.delayLineWrap());
                    Display d = new Display(terminal, false);
                    d.resize(size.getRows(), size.getColumns());
                    d.update(ls, -1);
                    redrawLine();
                    return new AttributedString("");
                }
                return pr.post;
            };
            if (!runLoop) {
                return false;
            }
            redisplay();
            // TODO: use a different keyMap ?
            Binding b = bindingReader.readBinding(getKeys());
            if (b instanceof Reference) {
                String name = ((Reference) b).name();
                if (BACKWARD_DELETE_CHAR.equals(name) || VI_BACKWARD_DELETE_CHAR.equals(name)) {
                    if (sb.length() == 0) {
                        pushBackBinding();
                        post = null;
                        return false;
                    } else {
                        sb.setLength(sb.length() - 1);
                        buf.backspace();
                    }
                } else if (SELF_INSERT.equals(name)) {
                    sb.append(getLastBinding());
                    buf.write(getLastBinding());
                    if (cands.isEmpty()) {
                        post = null;
                        return false;
                    }
                } else if ("\t".equals(getLastBinding())) {
                    if (cands.size() == 1 || sb.length() > 0) {
                        post = null;
                        pushBackBinding();
                    } else if (isSet(Option.AUTO_MENU)) {
                        buf.backspace(escaper.apply(current, false).length());
                        doMenu(cands, current, escaper);
                    }
                    return false;
                } else {
                    pushBackBinding();
                    post = null;
                    return false;
                }
            } else if (b == null) {
                post = null;
                return false;
            }
        }
    }

    protected static class PostResult {
        final AttributedString post;
        final int lines;
        final int selectedLine;

        public PostResult(AttributedString post, int lines, int selectedLine) {
            this.post = post;
            this.lines = lines;
            this.selectedLine = selectedLine;
        }
    }

    protected PostResult computePost(List<Candidate> possible, Candidate selection, List<Candidate> ordered, String completed) {
        return computePost(possible, selection, ordered, completed, display::wcwidth, size.getColumns(), isSet(Option.AUTO_GROUP), isSet(Option.GROUP), isSet(Option.LIST_ROWS_FIRST));
    }

    protected PostResult computePost(List<Candidate> possible, Candidate selection, List<Candidate> ordered, String completed, Function<String, Integer> wcwidth, int width, boolean autoGroup, boolean groupName, boolean rowsFirst) {
        List<Object> strings = new ArrayList<>();
        if (groupName) {
            Comparator<String> groupComparator = getGroupComparator();
            Map<String, Map<String, Candidate>> sorted;
            sorted = groupComparator != null
                        ? new TreeMap<>(groupComparator)
                        : new LinkedHashMap<>();
            for (Candidate cand : possible) {
                String group = cand.group();
                sorted.computeIfAbsent(group != null ? group : "", s -> new LinkedHashMap<>())
                        .put(cand.value(), cand);
            }
            for (Map.Entry<String, Map<String, Candidate>> entry : sorted.entrySet()) {
                String group = entry.getKey();
                if (group.isEmpty() && sorted.size() > 1) {
                    group = getOthersGroupName();
                }
                if (!group.isEmpty() && autoGroup) {
                    strings.add(group);
                }
                strings.add(new ArrayList<>(entry.getValue().values()));
                if (ordered != null) {
                    ordered.addAll(entry.getValue().values());
                }
            }
        } else {
            Set<String> groups = new LinkedHashSet<>();
            TreeMap<String, Candidate> sorted = new TreeMap<>();
            for (Candidate cand : possible) {
                String group = cand.group();
                if (group != null) {
                    groups.add(group);
                }
                sorted.put(cand.value(), cand);
            }
            if (autoGroup) {
                strings.addAll(groups);
            }
            strings.add(new ArrayList<>(sorted.values()));
            if (ordered != null) {
                ordered.addAll(sorted.values());
            }
        }
        return toColumns(strings, selection, completed, wcwidth, width, rowsFirst);
    }

    private static final String DESC_PREFIX = "(";
    private static final String DESC_SUFFIX = ")";
    private static final int MARGIN_BETWEEN_DISPLAY_AND_DESC = 1;
    private static final int MARGIN_BETWEEN_COLUMNS = 3;

    @SuppressWarnings("unchecked")
    protected PostResult toColumns(List<Object> items, Candidate selection, String completed, Function<String, Integer> wcwidth, int width, boolean rowsFirst) {
        int[] out = new int[2];
        // TODO: support Option.LIST_PACKED
        // Compute column width
        int maxWidth = 0;
        for (Object item : items) {
            if (item instanceof String) {
                int len = wcwidth.apply((String) item);
                maxWidth = Math.max(maxWidth, len);
            }
            else if (item instanceof List) {
                for (Candidate cand : (List<Candidate>) item) {
                    int len = wcwidth.apply(cand.displ());
                    if (cand.descr() != null) {
                        len += MARGIN_BETWEEN_DISPLAY_AND_DESC;
                        len += DESC_PREFIX.length();
                        len += wcwidth.apply(cand.descr());
                        len += DESC_SUFFIX.length();
                    }
                    maxWidth = Math.max(maxWidth, len);
                }
            }
        }
        // Build columns
        AttributedStringBuilder sb = new AttributedStringBuilder();
        for (Object list : items) {
            toColumns(list, width, maxWidth, sb, selection, completed, rowsFirst, out);
        }
        if (sb.length() > 0 && sb.charAt(sb.length() - 1) == '\n') {
            sb.setLength(sb.length() - 1);
        }
        return new PostResult(sb.toAttributedString(), out[0], out[1]);
    }

    @SuppressWarnings("unchecked")
    protected void toColumns(Object items, int width, int maxWidth, AttributedStringBuilder sb, Candidate selection, String completed, boolean rowsFirst, int[] out) {
        if (maxWidth <= 0) {
            return;
        }
        // This is a group
        if (items instanceof String) {
            sb.style(getCompletionStyleGroup())
                    .append((String) items)
                    .style(AttributedStyle.DEFAULT)
                    .append("\n");
            out[0]++;
        }
        // This is a Candidate list
        else if (items instanceof List) {
            List<Candidate> candidates = (List<Candidate>) items;
            maxWidth = Math.min(width, maxWidth);
            int c = width / maxWidth;
            while (c > 1 && c * maxWidth + (c - 1) * MARGIN_BETWEEN_COLUMNS >= width) {
                c--;
            }
            int lines = (candidates.size() + c - 1) / c;
            // Try to minimize the number of columns for the given number of rows
            // Prevents eg 9 candiates being split 6/3 instead of 5/4.
            final int columns = (candidates.size() + lines - 1) / lines;
            IntBinaryOperator index;
            if (rowsFirst) {
                index = (i, j) -> i * columns + j;
            } else {
                index = (i, j) -> j * lines + i;
            }
            for (int i = 0; i < lines; i++) {
                for (int j = 0; j < columns; j++) {
                    int idx = index.applyAsInt(i, j);
                    if (idx < candidates.size()) {
                        Candidate cand = candidates.get(idx);
                        boolean hasRightItem = j < columns - 1 && index.applyAsInt(i, j + 1) < candidates.size();
                        AttributedString left = AttributedString.fromAnsi(cand.displ());
                        AttributedString right = AttributedString.fromAnsi(cand.descr());
                        int lw = left.columnLength();
                        int rw = 0;
                        if (right != null) {
                            int rem = maxWidth - (lw + MARGIN_BETWEEN_DISPLAY_AND_DESC
                                    + DESC_PREFIX.length() + DESC_SUFFIX.length());
                            rw = right.columnLength();
                            if (rw > rem) {
                                right = AttributedStringBuilder.append(
                                            right.columnSubSequence(0, rem - WCWidth.wcwidth('\u2026')),
                                            "\u2026");
                                rw = right.columnLength();
                            }
                            right = AttributedStringBuilder.append(DESC_PREFIX, right, DESC_SUFFIX);
                            rw += DESC_PREFIX.length() + DESC_SUFFIX.length();
                        }
                        if (cand == selection) {
                            out[1] = i;
                            sb.style(getCompletionStyleSelection());
                            if (left.toString().regionMatches(
                                    isSet(Option.CASE_INSENSITIVE), 0, completed, 0, completed.length())) {
                                sb.append(left.toString(), 0, completed.length());
                                sb.append(left.toString(), completed.length(), left.length());
                            } else {
                                sb.append(left.toString());
                            }
                            for (int k = 0; k < maxWidth - lw - rw; k++) {
                                sb.append(' ');
                            }
                            if (right != null) {
                                sb.append(right);
                            }
                            sb.style(AttributedStyle.DEFAULT);
                        } else {
                            if (left.toString().regionMatches(
                                    isSet(Option.CASE_INSENSITIVE), 0, completed, 0, completed.length())) {
                                sb.style(getCompletionStyleStarting());
                                sb.append(left, 0, completed.length());
                                sb.style(AttributedStyle.DEFAULT);
                                sb.append(left, completed.length(), left.length());
                            } else {
                                sb.append(left);
                            }
                            if (right != null || hasRightItem) {
                                for (int k = 0; k < maxWidth - lw - rw; k++) {
                                    sb.append(' ');
                                }
                            }
                            if (right != null) {
                                sb.style(getCompletionStyleDescription());
                                sb.append(right);
                                sb.style(AttributedStyle.DEFAULT);
                            }
                        }
                        if (hasRightItem) {
                            for (int k = 0; k < MARGIN_BETWEEN_COLUMNS; k++) {
                                sb.append(' ');
                            }
                        }
                    }
                }
                sb.append('\n');
            }
            out[0] += lines;
        }
    }

    private AttributedStyle getCompletionStyleStarting() {
        return getCompletionStyle(COMPLETION_STYLE_STARTING, DEFAULT_COMPLETION_STYLE_STARTING);
    }

    protected AttributedStyle getCompletionStyleDescription() {
        return getCompletionStyle(COMPLETION_STYLE_DESCRIPTION, DEFAULT_COMPLETION_STYLE_DESCRIPTION);
    }

    protected AttributedStyle getCompletionStyleGroup() {
        return getCompletionStyle(COMPLETION_STYLE_GROUP, DEFAULT_COMPLETION_STYLE_GROUP);
    }

    protected AttributedStyle getCompletionStyleSelection() {
        return getCompletionStyle(COMPLETION_STYLE_SELECTION, DEFAULT_COMPLETION_STYLE_SELECTION);
    }

    protected AttributedStyle getCompletionStyle(String name, String value) {
        return buildStyle(getString(name, value));
    }

    protected AttributedStyle buildStyle(String str) {
        return AttributedString.fromAnsi("\u001b[" + str + "m ").styleAt(0);
    }

    private String getCommonStart(String str1, String str2, boolean caseInsensitive) {
        int[] s1 = str1.codePoints().toArray();
        int[] s2 = str2.codePoints().toArray();
        int len = 0;
        while (len < Math.min(s1.length, s2.length)) {
            int ch1 = s1[len];
            int ch2 = s2[len];
            if (ch1 != ch2 && caseInsensitive) {
                ch1 = Character.toUpperCase(ch1);
                ch2 = Character.toUpperCase(ch2);
                if (ch1 != ch2) {
                    ch1 = Character.toLowerCase(ch1);
                    ch2 = Character.toLowerCase(ch2);
                }
            }
            if (ch1 != ch2) {
                break;
            }
            len++;
        }
        return new String(s1, 0, len);
    }

    
Used in "vi" mode for argumented history move, to move a specific
number of history entries forward or back.
Params:
next – If true, move forward
count – The number of entries to move
Returns:
true if the move was successful/**
     * Used in "vi" mode for argumented history move, to move a specific
     * number of history entries forward or back.
     *
     * @param next If true, move forward
     * @param count The number of entries to move
     * @return true if the move was successful
     */
    protected boolean moveHistory(final boolean next, int count) {
        boolean ok = true;
        for (int i = 0; i < count && (ok = moveHistory(next)); i++) {
            /* empty */
        }
        return ok;
    }

    
Move up or down the history tree.
Params:
next – true to go to the next, false for the previous.
Returns:
true if successful, false otherwise/**
     * Move up or down the history tree.
     * @param next <code>true</code> to go to the next, <code>false</code> for the previous.
     * @return <code>true</code> if successful, <code>false</code> otherwise
     */
    protected boolean moveHistory(final boolean next) {
        if (!buf.toString().equals(history.current())) {
            modifiedHistory.put(history.index(), buf.toString());
        }
        if (next && !history.next()) {
            return false;
        }
        else if (!next && !history.previous()) {
            return false;
        }

        setBuffer(modifiedHistory.containsKey(history.index())
                    ? modifiedHistory.get(history.index())
                    : history.current());

        return true;
    }

    //
    // Printing
    //

    
Raw output printing.
Params:
str – the string to print to the terminal/**
     * Raw output printing.
     * @param str the string to print to the terminal
     */
    void print(String str) {
        terminal.writer().write(str);
    }

    void println(String s) {
        print(s);
        println();
    }

    
Output a platform-dependant newline.
/**
     * Output a platform-dependant newline.
     */
    void println() {
        terminal.puts(Capability.carriage_return);
        print("\n");
        redrawLine();
    }


    //
    // Actions
    //

    protected boolean killBuffer() {
        killRing.add(buf.toString());
        buf.clear();
        return true;
    }

    protected boolean killWholeLine() {
        if (buf.length() == 0) {
            return false;
        }
        int start;
        int end;
        if (count < 0) {
            end = buf.cursor();
            while (buf.atChar(end) != 0 && buf.atChar(end) != '\n') {
                end++;
            }
            start = end;
            for (int count = -this.count; count > 0; --count) {
                while (start > 0 && buf.atChar(start - 1) != '\n') {
                    start--;
                }
                start--;
            }
        } else {
            start = buf.cursor();
            while (start > 0 && buf.atChar(start - 1) != '\n') {
                start--;
            }
            end = start;
            while (count-- > 0) {
                while (end < buf.length() && buf.atChar(end) != '\n') {
                    end++;
                }
                end++;
            }
        }
        String killed = buf.substring(start, end);
        buf.cursor(start);
        buf.delete(end - start);
        killRing.add(killed);
        return true;
    }

    
Kill the buffer ahead of the current cursor position.
Returns:
true if successful/**
     * Kill the buffer ahead of the current cursor position.
     *
     * @return true if successful
     */
    public boolean killLine() {
        if (count < 0) {
            return callNeg(this::backwardKillLine);
        }
        if (buf.cursor() == buf.length()) {
            return false;
        }
        int cp = buf.cursor();
        int len = cp;
        while (count-- > 0) {
            if (buf.atChar(len) == '\n') {
                len++;
            } else {
                while (buf.atChar(len) != 0 && buf.atChar(len) != '\n') {
                    len++;
                }
            }
        }
        int num = len - cp;
        String killed = buf.substring(cp, cp + num);
        buf.delete(num);
        killRing.add(killed);
        return true;
    }

    public boolean backwardKillLine() {
        if (count < 0) {
            return callNeg(this::killLine);
        }
        if (buf.cursor() == 0) {
            return false;
        }
        int cp = buf.cursor();
        int beg = cp;
        while (count-- > 0) {
            if (beg == 0) {
                break;
            }
            if (buf.atChar(beg - 1) == '\n') {
                beg--;
            } else {
                while (beg > 0 && buf.atChar(beg - 1) != 0 && buf.atChar(beg - 1) != '\n') {
                    beg--;
                }
            }
        }
        int num = cp - beg;
        String killed = buf.substring(cp - beg, cp);
        buf.cursor(beg);
        buf.delete(num);
        killRing.add(killed);
        return true;
    }

    public boolean killRegion() {
        return doCopyKillRegion(true);
    }

    public boolean copyRegionAsKill() {
        return doCopyKillRegion(false);
    }

    private boolean doCopyKillRegion(boolean kill) {
        if (regionMark > buf.length()) {
            regionMark = buf.length();
        }
        if (regionActive == RegionType.LINE) {
            int start = regionMark;
            int end = buf.cursor();
            if (start < end) {
                while (start > 0 && buf.atChar(start - 1) != '\n') {
                    start--;
                }
                while (end < buf.length() - 1 && buf.atChar(end + 1) != '\n') {
                    end++;
                }
                if (isInViCmdMode()) {
                    end++;
                }
                killRing.add(buf.substring(start, end));
                if (kill) {
                    buf.backspace(end - start);
                }
            } else {
                while (end > 0 && buf.atChar(end - 1) != '\n') {
                    end--;
                }
                while (start < buf.length() && buf.atChar(start) != '\n') {
                    start++;
                }
                if (isInViCmdMode()) {
                    start++;
                }
                killRing.addBackwards(buf.substring(end, start));
                if (kill) {
                    buf.cursor(end);
                    buf.delete(start - end);
                }
            }
        } else if (regionMark > buf.cursor()) {
            if (isInViCmdMode()) {
                regionMark++;
            }
            killRing.add(buf.substring(buf.cursor(), regionMark));
            if (kill) {
                buf.delete(regionMark - buf.cursor());
            }
        } else {
            if (isInViCmdMode()) {
                buf.move(1);
            }
            killRing.add(buf.substring(regionMark, buf.cursor()));
            if (kill) {
                buf.backspace(buf.cursor() - regionMark);
            }
        }
        if (kill) {
            regionActive = RegionType.NONE;
        }
        return true;
    }

    public boolean yank() {
        String yanked = killRing.yank();
        if (yanked == null) {
            return false;
        } else {
            putString(yanked);
            return true;
        }
    }

    public boolean yankPop() {
        if (!killRing.lastYank()) {
            return false;
        }
        String current = killRing.yank();
        if (current == null) {
            // This shouldn't happen.
            return false;
        }
        buf.backspace(current.length());
        String yanked = killRing.yankPop();
        if (yanked == null) {
            // This shouldn't happen.
            return false;
        }

        putString(yanked);
        return true;
    }

    public boolean mouse() {
        MouseEvent event = readMouseEvent();
        if (event.getType() == MouseEvent.Type.Released
                && event.getButton() == MouseEvent.Button.Button1) {
            StringBuilder tsb = new StringBuilder();
            Cursor cursor = terminal.getCursorPosition(c -> tsb.append((char) c));
            bindingReader.runMacro(tsb.toString());

            List<AttributedString> secondaryPrompts = new ArrayList<>();
            getDisplayedBufferWithPrompts(secondaryPrompts);

            AttributedStringBuilder sb = new AttributedStringBuilder().tabs(TAB_WIDTH);
            sb.append(prompt);
            sb.append(insertSecondaryPrompts(new AttributedString(buf.upToCursor()), secondaryPrompts, false));
            List<AttributedString> promptLines = sb.columnSplitLength(size.getColumns(), false, display.delayLineWrap());

            int currentLine = promptLines.size() - 1;
            int wantedLine = Math.max(0, Math.min(currentLine + event.getY() - cursor.getY(), secondaryPrompts.size()));
            int pl0 = currentLine == 0 ? prompt.columnLength() : secondaryPrompts.get(currentLine - 1).columnLength();
            int pl1 = wantedLine == 0 ? prompt.columnLength() : secondaryPrompts.get(wantedLine - 1).columnLength();
            int adjust = pl1 - pl0;
            buf.moveXY(event.getX() - cursor.getX() - adjust, event.getY() - cursor.getY());
        }
        return true;
    }

    public boolean beginPaste() {
        final Object SELF_INSERT = new Object();
        final Object END_PASTE = new Object();
        KeyMap<Object> keyMap = new KeyMap<>();
        keyMap.setUnicode(SELF_INSERT);
        keyMap.setNomatch(SELF_INSERT);
        keyMap.setAmbiguousTimeout(0);
        keyMap.bind(END_PASTE, BRACKETED_PASTE_END);
        StringBuilder sb = new StringBuilder();
        while (true) {
            Object b = bindingReader.readBinding(keyMap);
            if (b == END_PASTE) {
                break;
            }
            String s = getLastBinding();
            if ("\r".equals(s)) {
                s = "\n";
            }
            sb.append(s);
        }
        regionActive = RegionType.PASTE;
        regionMark = getBuffer().cursor();
        getBuffer().write(sb);
        return true;
    }

    public boolean focusIn() {
        return false;
    }

    public boolean focusOut() {
        return false;
    }

    
Clean the used display
Returns:
true/**
     * Clean the used display
     * @return <code>true</code>
     */
    public boolean clear() {
        display.update(Collections.emptyList(), 0);
        return true;
    }

    
Clear the screen by issuing the ANSI "clear screen" code.
Returns:
true/**
     * Clear the screen by issuing the ANSI "clear screen" code.
     * @return <code>true</code>
     */
    public boolean clearScreen() {
        if (terminal.puts(Capability.clear_screen)) {
            Status status = Status.getStatus(terminal, false);
            if (status != null) {
                status.reset();
            }
            redrawLine();
        } else {
            println();
        }
        return true;
    }

    
Issue an audible keyboard bell.
Returns:
true/**
     * Issue an audible keyboard bell.
     * @return <code>true</code>
     */
    public boolean beep() {
        BellType bell_preference = BellType.AUDIBLE;
        switch (getString(BELL_STYLE, DEFAULT_BELL_STYLE).toLowerCase()) {
            case "none":
            case "off":
                bell_preference = BellType.NONE;
                break;
            case "audible":
                bell_preference = BellType.AUDIBLE;
                break;
            case "visible":
                bell_preference = BellType.VISIBLE;
                break;
            case "on":
                bell_preference = getBoolean(PREFER_VISIBLE_BELL, false)
                        ? BellType.VISIBLE : BellType.AUDIBLE;
                break;
        }
        if (bell_preference == BellType.VISIBLE) {
            if (terminal.puts(Capability.flash_screen)
                    || terminal.puts(Capability.bell)) {
                flush();
            }
        } else if (bell_preference == BellType.AUDIBLE) {
            if (terminal.puts(Capability.bell)) {
                flush();
            }
        }
        return true;
    }

    //
    // Helpers
    //

    
Checks to see if the specified character is a delimiter. We consider a
character a delimiter if it is anything but a letter or digit.
Params:
c –     The character to test
Returns:
     True if it is a delimiter/**
     * Checks to see if the specified character is a delimiter. We consider a
     * character a delimiter if it is anything but a letter or digit.
     *
     * @param c     The character to test
     * @return      True if it is a delimiter
     */
    protected boolean isDelimiter(int c) {
        return !Character.isLetterOrDigit(c);
    }

    
Checks to see if a character is a whitespace character. Currently this delegates to Character.isWhitespace(char), however eventually it should be hooked up so that the definition of whitespace can be configured, as readline does. 
Params:
c – The character to check
Returns:
true if the character is a whitespace/**
     * Checks to see if a character is a whitespace character. Currently
     * this delegates to {@link Character#isWhitespace(char)}, however
     * eventually it should be hooked up so that the definition of whitespace
     * can be configured, as readline does.
     *
     * @param c The character to check
     * @return true if the character is a whitespace
     */
    protected boolean isWhitespace(int c) {
        return Character.isWhitespace(c);
    }

    protected boolean isViAlphaNum(int c) {
        return c == '_' || Character.isLetterOrDigit(c);
    }

    protected boolean isAlpha(int c) {
        return Character.isLetter(c);
    }

    protected boolean isWord(int c) {
        String wordchars = getString(WORDCHARS, DEFAULT_WORDCHARS);
        return Character.isLetterOrDigit(c)
                || (c < 128 && wordchars.indexOf((char) c) >= 0);
    }

    String getString(String name, String def) {
        return ReaderUtils.getString(this, name, def);
    }

    boolean getBoolean(String name, boolean def) {
        return ReaderUtils.getBoolean(this, name, def);
    }

    int getInt(String name, int def) {
        return ReaderUtils.getInt(this, name, def);
    }

    long getLong(String name, long def) {
        return ReaderUtils.getLong(this, name, def);
    }

    @Override
    public Map<String, KeyMap<Binding>> defaultKeyMaps() {
        Map<String, KeyMap<Binding>> keyMaps = new HashMap<>();
        keyMaps.put(EMACS, emacs());
        keyMaps.put(VICMD, viCmd());
        keyMaps.put(VIINS, viInsertion());
        keyMaps.put(MENU, menu());
        keyMaps.put(VIOPP, viOpp());
        keyMaps.put(VISUAL, visual());
        keyMaps.put(SAFE, safe());
        if (getBoolean(BIND_TTY_SPECIAL_CHARS, true)) {
            Attributes attr = terminal.getAttributes();
            bindConsoleChars(keyMaps.get(EMACS), attr);
            bindConsoleChars(keyMaps.get(VIINS), attr);
        }
        // Put default
        for (KeyMap<Binding> keyMap : keyMaps.values()) {
            keyMap.setUnicode(new Reference(SELF_INSERT));
            keyMap.setAmbiguousTimeout(getLong(AMBIGUOUS_BINDING, DEFAULT_AMBIGUOUS_BINDING));
        }
        // By default, link main to emacs
        keyMaps.put(MAIN, keyMaps.get(EMACS));
        return keyMaps;
    }

    public KeyMap<Binding> emacs() {
        KeyMap<Binding> emacs = new KeyMap<>();
        bind(emacs, SET_MARK_COMMAND,                       ctrl('@'));
        bind(emacs, BEGINNING_OF_LINE,                      ctrl('A'));
        bind(emacs, BACKWARD_CHAR,                          ctrl('B'));
        bind(emacs, DELETE_CHAR_OR_LIST,                    ctrl('D'));
        bind(emacs, END_OF_LINE,                            ctrl('E'));
        bind(emacs, FORWARD_CHAR,                           ctrl('F'));
        bind(emacs, SEND_BREAK,                             ctrl('G'));
        bind(emacs, BACKWARD_DELETE_CHAR,                   ctrl('H'));
        bind(emacs, EXPAND_OR_COMPLETE,                     ctrl('I'));
        bind(emacs, ACCEPT_LINE,                            ctrl('J'));
        bind(emacs, KILL_LINE,                              ctrl('K'));
        bind(emacs, CLEAR_SCREEN,                           ctrl('L'));
        bind(emacs, ACCEPT_LINE,                            ctrl('M'));
        bind(emacs, DOWN_LINE_OR_HISTORY,                   ctrl('N'));
        bind(emacs, UP_LINE_OR_HISTORY,                     ctrl('P'));
        bind(emacs, HISTORY_INCREMENTAL_SEARCH_BACKWARD,    ctrl('R'));
        bind(emacs, HISTORY_INCREMENTAL_SEARCH_FORWARD,     ctrl('S'));
        bind(emacs, TRANSPOSE_CHARS,                        ctrl('T'));
        bind(emacs, KILL_WHOLE_LINE,                        ctrl('U'));
        bind(emacs, QUOTED_INSERT,                          ctrl('V'));
        bind(emacs, BACKWARD_KILL_WORD,                     ctrl('W'));
        bind(emacs, YANK,                                   ctrl('Y'));
        bind(emacs, CHARACTER_SEARCH,                       ctrl(']'));
        bind(emacs, UNDO,                                   ctrl('_'));
        bind(emacs, SELF_INSERT,                            range(" -~"));
        bind(emacs, INSERT_CLOSE_PAREN,                     ")");
        bind(emacs, INSERT_CLOSE_SQUARE,                    "]");
        bind(emacs, INSERT_CLOSE_CURLY,                     "}");
        bind(emacs, BACKWARD_DELETE_CHAR,                   del());
        bind(emacs, VI_MATCH_BRACKET,                       translate("^X^B"));
        bind(emacs, SEND_BREAK,                             translate("^X^G"));
        bind(emacs, VI_FIND_NEXT_CHAR,                      translate("^X^F"));
        bind(emacs, VI_JOIN,                                translate("^X^J"));
        bind(emacs, KILL_BUFFER,                            translate("^X^K"));
        bind(emacs, INFER_NEXT_HISTORY,                     translate("^X^N"));
        bind(emacs, OVERWRITE_MODE,                         translate("^X^O"));
        bind(emacs, REDO,                                   translate("^X^R"));
        bind(emacs, UNDO,                                   translate("^X^U"));
        bind(emacs, VI_CMD_MODE,                            translate("^X^V"));
        bind(emacs, EXCHANGE_POINT_AND_MARK,                translate("^X^X"));
        bind(emacs, DO_LOWERCASE_VERSION,                   translate("^XA-^XZ"));
        bind(emacs, WHAT_CURSOR_POSITION,                   translate("^X="));
        bind(emacs, KILL_LINE,                              translate("^X^?"));
        bind(emacs, SEND_BREAK,                             alt(ctrl('G')));
        bind(emacs, BACKWARD_KILL_WORD,                     alt(ctrl('H')));
        bind(emacs, SELF_INSERT_UNMETA,                     alt(ctrl('M')));
        bind(emacs, COMPLETE_WORD,                          alt(esc()));
        bind(emacs, CHARACTER_SEARCH_BACKWARD,              alt(ctrl(']')));
        bind(emacs, COPY_PREV_WORD,                         alt(ctrl('_')));
        bind(emacs, SET_MARK_COMMAND,                       alt(' '));
        bind(emacs, NEG_ARGUMENT,                           alt('-'));
        bind(emacs, DIGIT_ARGUMENT,                         range("\\E0-\\E9"));
        bind(emacs, BEGINNING_OF_HISTORY,                   alt('<'));
        bind(emacs, LIST_CHOICES,                           alt('='));
        bind(emacs, END_OF_HISTORY,                         alt('>'));
        bind(emacs, LIST_CHOICES,                           alt('?'));
        bind(emacs, DO_LOWERCASE_VERSION,                   range("^[A-^[Z"));
        bind(emacs, BACKWARD_WORD,                          alt('b'));
        bind(emacs, CAPITALIZE_WORD,                        alt('c'));
        bind(emacs, KILL_WORD,                              alt('d'));
        bind(emacs, KILL_WORD,                              translate("^[[3;5~")); // ctrl-delete
        bind(emacs, FORWARD_WORD,                           alt('f'));
        bind(emacs, DOWN_CASE_WORD,                         alt('l'));
        bind(emacs, HISTORY_SEARCH_FORWARD,                 alt('n'));
        bind(emacs, HISTORY_SEARCH_BACKWARD,                alt('p'));
        bind(emacs, TRANSPOSE_WORDS,                        alt('t'));
        bind(emacs, UP_CASE_WORD,                           alt('u'));
        bind(emacs, YANK_POP,                               alt('y'));
        bind(emacs, BACKWARD_KILL_WORD,                     alt(del()));
        bindArrowKeys(emacs);
        bind(emacs, FORWARD_WORD,                           translate("^[[1;5C")); // ctrl-left
        bind(emacs, BACKWARD_WORD,                          translate("^[[1;5D")); // ctrl-right
        bind(emacs, FORWARD_WORD,                           alt(key(Capability.key_right)));
        bind(emacs, BACKWARD_WORD,                          alt(key(Capability.key_left)));
        bind(emacs, FORWARD_WORD,                           alt(translate("^[[C")));
        bind(emacs, BACKWARD_WORD,                          alt(translate("^[[D")));
        return emacs;
    }

    public KeyMap<Binding> viInsertion() {
        KeyMap<Binding> viins = new KeyMap<>();
        bind(viins, SELF_INSERT,                            range("^@-^_"));
        bind(viins, LIST_CHOICES,                           ctrl('D'));
        bind(viins, SEND_BREAK,                             ctrl('G'));
        bind(viins, BACKWARD_DELETE_CHAR,                   ctrl('H'));
        bind(viins, EXPAND_OR_COMPLETE,                     ctrl('I'));
        bind(viins, ACCEPT_LINE,                            ctrl('J'));
        bind(viins, CLEAR_SCREEN,                           ctrl('L'));
        bind(viins, ACCEPT_LINE,                            ctrl('M'));
        bind(viins, MENU_COMPLETE,                          ctrl('N'));
        bind(viins, REVERSE_MENU_COMPLETE,                  ctrl('P'));
        bind(viins, HISTORY_INCREMENTAL_SEARCH_BACKWARD,    ctrl('R'));
        bind(viins, HISTORY_INCREMENTAL_SEARCH_FORWARD,     ctrl('S'));
        bind(viins, TRANSPOSE_CHARS,                        ctrl('T'));
        bind(viins, KILL_WHOLE_LINE,                        ctrl('U'));
        bind(viins, QUOTED_INSERT,                          ctrl('V'));
        bind(viins, BACKWARD_KILL_WORD,                     ctrl('W'));
        bind(viins, YANK,                                   ctrl('Y'));
        bind(viins, VI_CMD_MODE,                            ctrl('['));
        bind(viins, UNDO,                                   ctrl('_'));
        bind(viins, HISTORY_INCREMENTAL_SEARCH_BACKWARD,    ctrl('X') + "r");
        bind(viins, HISTORY_INCREMENTAL_SEARCH_FORWARD,     ctrl('X') + "s");
        bind(viins, SELF_INSERT,                            range(" -~"));
        bind(viins, INSERT_CLOSE_PAREN,                     ")");
        bind(viins, INSERT_CLOSE_SQUARE,                    "]");
        bind(viins, INSERT_CLOSE_CURLY,                     "}");
        bind(viins, BACKWARD_DELETE_CHAR,                   del());
        bindArrowKeys(viins);
        return viins;
    }

    public KeyMap<Binding> viCmd() {
        KeyMap<Binding> vicmd = new KeyMap<>();
        bind(vicmd, LIST_CHOICES,                           ctrl('D'));
        bind(vicmd, EMACS_EDITING_MODE,                     ctrl('E'));
        bind(vicmd, SEND_BREAK,                             ctrl('G'));
        bind(vicmd, VI_BACKWARD_CHAR,                       ctrl('H'));
        bind(vicmd, ACCEPT_LINE,                            ctrl('J'));
        bind(vicmd, KILL_LINE,                              ctrl('K'));
        bind(vicmd, CLEAR_SCREEN,                           ctrl('L'));
        bind(vicmd, ACCEPT_LINE,                            ctrl('M'));
        bind(vicmd, VI_DOWN_LINE_OR_HISTORY,                ctrl('N'));
        bind(vicmd, VI_UP_LINE_OR_HISTORY,                  ctrl('P'));
        bind(vicmd, QUOTED_INSERT,                          ctrl('Q'));
        bind(vicmd, HISTORY_INCREMENTAL_SEARCH_BACKWARD,    ctrl('R'));
        bind(vicmd, HISTORY_INCREMENTAL_SEARCH_FORWARD,     ctrl('S'));
        bind(vicmd, TRANSPOSE_CHARS,                        ctrl('T'));
        bind(vicmd, KILL_WHOLE_LINE,                        ctrl('U'));
        bind(vicmd, QUOTED_INSERT,                          ctrl('V'));
        bind(vicmd, BACKWARD_KILL_WORD,                     ctrl('W'));
        bind(vicmd, YANK,                                   ctrl('Y'));
        bind(vicmd, HISTORY_INCREMENTAL_SEARCH_BACKWARD,    ctrl('X') + "r");
        bind(vicmd, HISTORY_INCREMENTAL_SEARCH_FORWARD,     ctrl('X') + "s");
        bind(vicmd, SEND_BREAK,                             alt(ctrl('G')));
        bind(vicmd, BACKWARD_KILL_WORD,                     alt(ctrl('H')));
        bind(vicmd, SELF_INSERT_UNMETA,                     alt(ctrl('M')));
        bind(vicmd, COMPLETE_WORD,                          alt(esc()));
        bind(vicmd, CHARACTER_SEARCH_BACKWARD,              alt(ctrl(']')));
        bind(vicmd, SET_MARK_COMMAND,                       alt(' '));
//        bind(vicmd, INSERT_COMMENT,                         alt('#'));
//        bind(vicmd, INSERT_COMPLETIONS,                     alt('*'));
        bind(vicmd, DIGIT_ARGUMENT,                         alt('-'));
        bind(vicmd, BEGINNING_OF_HISTORY,                   alt('<'));
        bind(vicmd, LIST_CHOICES,                           alt('='));
        bind(vicmd, END_OF_HISTORY,                         alt('>'));
        bind(vicmd, LIST_CHOICES,                           alt('?'));
        bind(vicmd, DO_LOWERCASE_VERSION,                   range("^[A-^[Z"));
        bind(vicmd, BACKWARD_WORD,                          alt('b'));
        bind(vicmd, CAPITALIZE_WORD,                        alt('c'));
        bind(vicmd, KILL_WORD,                              alt('d'));
        bind(vicmd, FORWARD_WORD,                           alt('f'));
        bind(vicmd, DOWN_CASE_WORD,                         alt('l'));
        bind(vicmd, HISTORY_SEARCH_FORWARD,                 alt('n'));
        bind(vicmd, HISTORY_SEARCH_BACKWARD,                alt('p'));
        bind(vicmd, TRANSPOSE_WORDS,                        alt('t'));
        bind(vicmd, UP_CASE_WORD,                           alt('u'));
        bind(vicmd, YANK_POP,                               alt('y'));
        bind(vicmd, BACKWARD_KILL_WORD,                     alt(del()));

        bind(vicmd, FORWARD_CHAR,                           " ");
        bind(vicmd, VI_INSERT_COMMENT,                      "#");
        bind(vicmd, END_OF_LINE,                            "$");
        bind(vicmd, VI_MATCH_BRACKET,                       "%");
        bind(vicmd, VI_DOWN_LINE_OR_HISTORY,                "+");
        bind(vicmd, VI_REV_REPEAT_FIND,                     ",");
        bind(vicmd, VI_UP_LINE_OR_HISTORY,                  "-");
        bind(vicmd, VI_REPEAT_CHANGE,                       ".");
        bind(vicmd, VI_HISTORY_SEARCH_BACKWARD,             "/");
        bind(vicmd, VI_DIGIT_OR_BEGINNING_OF_LINE,          "0");
        bind(vicmd, DIGIT_ARGUMENT,                         range("1-9"));
        bind(vicmd, VI_REPEAT_FIND,                         ";");
        bind(vicmd, LIST_CHOICES,                           "=");
        bind(vicmd, VI_HISTORY_SEARCH_FORWARD,              "?");
        bind(vicmd, VI_ADD_EOL,                             "A");
        bind(vicmd, VI_BACKWARD_BLANK_WORD,                 "B");
        bind(vicmd, VI_CHANGE_EOL,                          "C");
        bind(vicmd, VI_KILL_EOL,                            "D");
        bind(vicmd, VI_FORWARD_BLANK_WORD_END,              "E");
        bind(vicmd, VI_FIND_PREV_CHAR,                      "F");
        bind(vicmd, VI_FETCH_HISTORY,                       "G");
        bind(vicmd, VI_INSERT_BOL,                          "I");
        bind(vicmd, VI_JOIN,                                "J");
        bind(vicmd, VI_REV_REPEAT_SEARCH,                   "N");
        bind(vicmd, VI_OPEN_LINE_ABOVE,                     "O");
        bind(vicmd, VI_PUT_BEFORE,                          "P");
        bind(vicmd, VI_REPLACE,                             "R");
        bind(vicmd, VI_KILL_LINE,                           "S");
        bind(vicmd, VI_FIND_PREV_CHAR_SKIP,                 "T");
        bind(vicmd, REDO,                                   "U");
        bind(vicmd, VISUAL_LINE_MODE,                       "V");
        bind(vicmd, VI_FORWARD_BLANK_WORD,                  "W");
        bind(vicmd, VI_BACKWARD_DELETE_CHAR,                "X");
        bind(vicmd, VI_YANK_WHOLE_LINE,                     "Y");
        bind(vicmd, VI_FIRST_NON_BLANK,                     "^");
        bind(vicmd, VI_ADD_NEXT,                            "a");
        bind(vicmd, VI_BACKWARD_WORD,                       "b");
        bind(vicmd, VI_CHANGE,                              "c");
        bind(vicmd, VI_DELETE,                              "d");
        bind(vicmd, VI_FORWARD_WORD_END,                    "e");
        bind(vicmd, VI_FIND_NEXT_CHAR,                      "f");
        bind(vicmd, WHAT_CURSOR_POSITION,                   "ga");
        bind(vicmd, VI_BACKWARD_BLANK_WORD_END,             "gE");
        bind(vicmd, VI_BACKWARD_WORD_END,                   "ge");
        bind(vicmd, VI_BACKWARD_CHAR,                       "h");
        bind(vicmd, VI_INSERT,                              "i");
        bind(vicmd, DOWN_LINE_OR_HISTORY,                   "j");
        bind(vicmd, UP_LINE_OR_HISTORY,                     "k");
        bind(vicmd, VI_FORWARD_CHAR,                        "l");
        bind(vicmd, VI_REPEAT_SEARCH,                       "n");
        bind(vicmd, VI_OPEN_LINE_BELOW,                     "o");
        bind(vicmd, VI_PUT_AFTER,                           "p");
        bind(vicmd, VI_REPLACE_CHARS,                       "r");
        bind(vicmd, VI_SUBSTITUTE,                          "s");
        bind(vicmd, VI_FIND_NEXT_CHAR_SKIP,                 "t");
        bind(vicmd, UNDO,                                   "u");
        bind(vicmd, VISUAL_MODE,                            "v");
        bind(vicmd, VI_FORWARD_WORD,                        "w");
        bind(vicmd, VI_DELETE_CHAR,                         "x");
        bind(vicmd, VI_YANK,                                "y");
        bind(vicmd, VI_GOTO_COLUMN,                         "|");
        bind(vicmd, VI_SWAP_CASE,                           "~");
        bind(vicmd, VI_BACKWARD_CHAR,                       del());

        bindArrowKeys(vicmd);
        return vicmd;
    }

    public KeyMap<Binding> menu() {
        KeyMap<Binding> menu = new KeyMap<>();
        bind(menu, MENU_COMPLETE,                     "\t");
        bind(menu, REVERSE_MENU_COMPLETE,             key(Capability.back_tab));
        bind(menu, ACCEPT_LINE,                       "\r", "\n");
        bindArrowKeys(menu);
        return menu;
    }

    public KeyMap<Binding> safe() {
        KeyMap<Binding> safe = new KeyMap<>();
        bind(safe, SELF_INSERT,                 range("^@-^?"));
        bind(safe, ACCEPT_LINE,                 "\r", "\n");
        bind(safe, SEND_BREAK,                  ctrl('G'));
        return safe;
    }

    public KeyMap<Binding> visual() {
        KeyMap<Binding> visual = new KeyMap<>();
        bind(visual, UP_LINE,                   key(Capability.key_up),     "k");
        bind(visual, DOWN_LINE,                 key(Capability.key_down),   "j");
        bind(visual, this::deactivateRegion,    esc());
        bind(visual, EXCHANGE_POINT_AND_MARK,   "o");
        bind(visual, PUT_REPLACE_SELECTION,     "p");
        bind(visual, VI_DELETE,                 "x");
        bind(visual, VI_OPER_SWAP_CASE,         "~");
        return visual;
    }

    public KeyMap<Binding> viOpp() {
        KeyMap<Binding> viOpp = new KeyMap<>();
        bind(viOpp, UP_LINE,                    key(Capability.key_up),     "k");
        bind(viOpp, DOWN_LINE,                  key(Capability.key_down),   "j");
        bind(viOpp, VI_CMD_MODE,                esc());
        return viOpp;
    }

    private void bind(KeyMap<Binding> map, String widget, Iterable<? extends CharSequence> keySeqs) {
        map.bind(new Reference(widget), keySeqs);
    }

    private void bind(KeyMap<Binding> map, String widget, CharSequence... keySeqs) {
        map.bind(new Reference(widget), keySeqs);
    }

    private void bind(KeyMap<Binding> map, Widget widget, CharSequence... keySeqs) {
        map.bind(widget, keySeqs);
    }

    private String key(Capability capability) {
        return KeyMap.key(terminal, capability);
    }

    private void bindArrowKeys(KeyMap<Binding> map) {
        bind(map, UP_LINE_OR_SEARCH,    key(Capability.key_up));
        bind(map, DOWN_LINE_OR_SEARCH,  key(Capability.key_down));
        bind(map, BACKWARD_CHAR,        key(Capability.key_left));
        bind(map, FORWARD_CHAR,         key(Capability.key_right));
        bind(map, BEGINNING_OF_LINE,    key(Capability.key_home));
        bind(map, END_OF_LINE,          key(Capability.key_end));
        bind(map, DELETE_CHAR,          key(Capability.key_dc));
        bind(map, KILL_WHOLE_LINE,      key(Capability.key_dl));
        bind(map, OVERWRITE_MODE,       key(Capability.key_ic));
        bind(map, MOUSE,                key(Capability.key_mouse));
        bind(map, BEGIN_PASTE,          BRACKETED_PASTE_BEGIN);
        bind(map, FOCUS_IN,             FOCUS_IN_SEQ);
        bind(map, FOCUS_OUT,            FOCUS_OUT_SEQ);
    }

    
Bind special chars defined by the terminal instead of
the default bindings
/**
     * Bind special chars defined by the terminal instead of
     * the default bindings
     */
    private void bindConsoleChars(KeyMap<Binding> keyMap, Attributes attr) {
        if (attr != null) {
            rebind(keyMap, BACKWARD_DELETE_CHAR,
                    del(), (char) attr.getControlChar(ControlChar.VERASE));
            rebind(keyMap, BACKWARD_KILL_WORD,
                    ctrl('W'),  (char) attr.getControlChar(ControlChar.VWERASE));
            rebind(keyMap, KILL_WHOLE_LINE,
                    ctrl('U'), (char) attr.getControlChar(ControlChar.VKILL));
            rebind(keyMap, QUOTED_INSERT,
                    ctrl('V'), (char) attr.getControlChar(ControlChar.VLNEXT));
        }
    }

    private void rebind(KeyMap<Binding> keyMap, String operation, String prevBinding, char newBinding) {
        if (newBinding > 0 && newBinding < 128) {
            Reference ref = new Reference(operation);
            bind(keyMap, SELF_INSERT, prevBinding);
            keyMap.bind(ref, Character.toString(newBinding));
        }
    }


}