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package jdk.nashorn.internal.runtime.regexp;

import static java.util.regex.Pattern.CASE_INSENSITIVE;
import static java.util.regex.Pattern.MULTILINE;
import static java.util.regex.Pattern.UNICODE_CASE;

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import jdk.nashorn.internal.runtime.ParserException;

Default regular expression implementation based on java.util.regex package. Note that this class is not thread-safe as it stores the current match result and the string being matched in instance fields.
/** * Default regular expression implementation based on java.util.regex package. * * Note that this class is not thread-safe as it stores the current match result * and the string being matched in instance fields. */
public class JdkRegExp extends RegExp {
Java regexp pattern to use for match. We compile to one of these
/** Java regexp pattern to use for match. We compile to one of these */
private Pattern pattern;
Construct a Regular expression from the given source and flags strings.
Params:
  • source – RegExp source string
  • flags – RegExp flag string
Throws:
/** * Construct a Regular expression from the given {@code source} and {@code flags} strings. * * @param source RegExp source string * @param flags RegExp flag string * @throws ParserException if flags is invalid or source string has syntax error. */
public JdkRegExp(final String source, final String flags) throws ParserException { super(source, flags); int intFlags = 0; if (isIgnoreCase()) { intFlags |= CASE_INSENSITIVE | UNICODE_CASE; } if (isMultiline()) { intFlags |= MULTILINE; } try { RegExpScanner parsed; try { parsed = RegExpScanner.scan(source); } catch (final PatternSyntaxException e) { // refine the exception with a better syntax error, if this // passes, just rethrow what we have Pattern.compile(source, intFlags); throw e; } if (parsed != null) { this.pattern = Pattern.compile(parsed.getJavaPattern(), intFlags); this.groupsInNegativeLookahead = parsed.getGroupsInNegativeLookahead(); } } catch (final PatternSyntaxException e2) { throwParserException("syntax", e2.getMessage()); } } @Override public RegExpMatcher match(final String str) { if (pattern == null) { return null; // never matches or similar, e.g. a[] } return new DefaultMatcher(str); } class DefaultMatcher implements RegExpMatcher { final String input; final Matcher defaultMatcher; DefaultMatcher(final String input) { this.input = input; this.defaultMatcher = pattern.matcher(input); } @Override public boolean search(final int start) { return defaultMatcher.find(start); } @Override public String getInput() { return input; } @Override public int start() { return defaultMatcher.start(); } @Override public int start(final int group) { return defaultMatcher.start(group); } @Override public int end() { return defaultMatcher.end(); } @Override public int end(final int group) { return defaultMatcher.end(group); } @Override public String group() { return defaultMatcher.group(); } @Override public String group(final int group) { return defaultMatcher.group(group); } @Override public int groupCount() { return defaultMatcher.groupCount(); } } }