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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.jshell;

import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

Within a String, mask code comments and ignored modifiers (within context).
Author:Robert Field
/** * Within a String, mask code comments and ignored modifiers (within context). * * @author Robert Field */
class MaskCommentsAndModifiers { private final static Set<String> IGNORED_MODIFIERS = Stream.of( "public", "protected", "private", "static" ) .collect( Collectors.toSet() ); private final static Set<String> OTHER_MODIFIERS = Stream.of( "abstract", "strictfp", "transient", "volatile", "synchronized", "native", "default", "final" ) .collect( Collectors.toSet() ); // Builder to accumulate non-masked characters private final StringBuilder sbCleared = new StringBuilder(); // Builder to accumulate masked characters private final StringBuilder sbMask = new StringBuilder(); // The input string private final String str; // Entire input string length private final int length; // The next character position private int next = 0; // The current character private int c; // Do we mask-off ignored modifiers? Set by parameter and turned off after // initial modifier section private boolean maskModifiers; // Does the string end with an unclosed '/*' style comment? private boolean openToken = false; MaskCommentsAndModifiers(String s, boolean maskModifiers) { this.str = s; this.length = s.length(); this.maskModifiers = maskModifiers; read(); while (c >= 0) { next(); read(); } } String cleared() { return sbCleared.toString(); } String mask() { return sbMask.toString(); } boolean endsWithOpenToken() { return openToken; } /****** private implementation methods ******/
Read the next character
/** * Read the next character */
private int read() { return c = (next >= length) ? -1 : str.charAt(next++); } private void unread() { if (c >= 0) { --next; } } private void writeTo(StringBuilder sb, int ch) { sb.append((char)ch); } private void write(int ch) { if (ch != -1) { writeTo(sbCleared, ch); writeTo(sbMask, Character.isWhitespace(ch) ? ch : ' '); } } private void writeMask(int ch) { if (ch != -1) { writeTo(sbMask, ch); writeTo(sbCleared, Character.isWhitespace(ch) ? ch : ' '); } } private void write(CharSequence s) { for (int cp : s.chars().toArray()) { write(cp); } } private void writeMask(CharSequence s) { for (int cp : s.chars().toArray()) { writeMask(cp); } } @SuppressWarnings("fallthrough") private void next() { switch (c) { case '"': { int pos = next - 1; maskModifiers = false; if (str.startsWith("\"\"\"", next - 1)) { //text block/multi-line string literal: int searchPoint = next + 2; int end; while ((end = str.indexOf("\"\"\"", searchPoint)) != (-1)) { if (str.charAt(end - 1) != '\\') break; searchPoint = end + 1; } if (end == (-1)) { openToken = true; end = str.length(); } else { end += 3; } write(c); while (next < end) { write(read()); } break; } } //intentional fall-through: case '\'': { maskModifiers = false; write(c); int match = c; while (read() >= 0 && c != match && c != '\n' && c != '\r') { write(c); if (c == '\\') { write(read()); } } write(c); // write match // line-end break; } case '/': read(); switch (c) { case '*': writeMask('/'); writeMask(c); int prevc = 0; while (read() >= 0 && (c != '/' || prevc != '*')) { writeMask(c); prevc = c; } writeMask(c); openToken = c < 0; break; case '/': writeMask('/'); writeMask(c); while (read() >= 0 && c != '\n' && c != '\r') { writeMask(c); } writeMask(c); break; default: maskModifiers = false; write('/'); unread(); break; } break; case '@': do { write(c); read(); } while (Character.isJavaIdentifierPart(c)); while (Character.isWhitespace(c)) { write(c); read(); } // if this is an annotation with arguments, process those recursively if (c == '(') { write(c); boolean prevMaskModifiers = maskModifiers; int parenCnt = 1; while (read() >= 0) { if (c == ')') { if (--parenCnt == 0) { break; } } else if (c == '(') { ++parenCnt; } next(); // recurse to handle quotes and comments } write(c); // stuff in annotation arguments doesn't effect inside determination maskModifiers = prevMaskModifiers; } else { unread(); } break; default: if (Character.isJavaIdentifierStart(c)) { StringBuilder sb = new StringBuilder(); do { writeTo(sb, c); read(); } while (Character.isJavaIdentifierPart(c)); unread(); String id = sb.toString(); if (maskModifiers && IGNORED_MODIFIERS.contains(id)) { writeMask(sb); } else { write(sb); if (maskModifiers && !OTHER_MODIFIERS.contains(id)) { maskModifiers = false; } } } else { if (!Character.isWhitespace(c)) { maskModifiers = false; } write(c); } break; } } }