/**
* <strong>[11.8.5] Regular Expression Literals</strong>
*
* <pre>
* RegularExpressionLiteral ::
* / RegularExpressionBody / RegularExpressionFlags
* RegularExpressionBody ::
* RegularExpressionFirstChar RegularExpressionChars
* RegularExpressionChars ::
* [empty]
* RegularExpressionChars RegularExpressionChar
* RegularExpressionFirstChar ::
* RegularExpressionNonTerminator but not one of * or \ or / or [
* RegularExpressionBackslashSequence
* RegularExpressionClass
* RegularExpressionChar ::
* RegularExpressionNonTerminator but not one of \ or / or [
* RegularExpressionBackslashSequence
* RegularExpressionClass
* RegularExpressionBackslashSequence ::
* \ RegularExpressionNonTerminator
* RegularExpressionNonTerminator ::
* SourceCharacter but not LineTerminator
* RegularExpressionClass ::
* [ RegularExpressionClassChars ]
* RegularExpressionClassChars ::
* [empty]
* RegularExpressionClassChars RegularExpressionClassChar
* RegularExpressionClassChar ::
* RegularExpressionNonTerminator but not one of ] or \
* RegularExpressionBackslashSequence
* RegularExpressionFlags ::
* [empty]
* RegularExpressionFlags IdentifierPart
* </pre>
*/
public String[] readRegularExpression(Token start) {
assert start == Token.DIV || start == Token.ASSIGN_DIV;
assert next == null : "regular expression in lookahead";
final int EOF = TokenStreamInput.EOF;
TokenStreamInput input = this.input;
StringBuffer buffer = buffer();
if (start == Token.ASSIGN_DIV) {
buffer.add('=');
} else {
int c = input.peek(0);
if (c == '/' || c == '*') {
throw error(Messages.Key.InvalidRegExpLiteral);
}
}
boolean inClass = false;
for (; ; ) {
int c = input.get();
if (c == '\\') {
// escape sequence
buffer.add(c);
c = input.get();
} else if (c == '[') {
inClass = true;
} else if (c == ']') {
inClass = false;
} else if (c == '/' && !inClass) {
break;
}
if (c == EOF || isLineTerminator(c)) {
throw error(Messages.Key.UnterminatedRegExpLiteral);
}
buffer.add(c);
}
String regexp = buffer.toString();
buffer.clear();
for (; ; ) {
int c = input.get();
if (!isIdentifierPart(c)) {
if (c == '\\' && match('u')) {
readUnicode();
throw error(Messages.Key.UnicodeEscapeInRegExpFlags);
}
input.unget(c);
break;
}
buffer.add(c);
}
String flags = buffer.toString();
return new String[] {regexp, flags};
}
private StringBuffer buffer() {
StringBuffer buffer = this.buffer;
buffer.clear();
return buffer;
}