/** Creates a properly-configured parser object for the E4X grammar. */
public static RegexSimpleParser parserOn(Reader in) throws IOException {
ANTLRReaderStream cs = new ANTLRReaderStream(in);
RegexSimpleLexer lexer = new RegexSimpleLexer(cs);
LinkedListTokenSource source = new LinkedListTokenSource(lexer);
LinkedListTokenStream stream = new LinkedListTokenStream(source);
RegexSimpleParser parser = new RegexSimpleParser(stream);
parser.setTreeAdaptor(TREE_ADAPTOR);
parser.setInput(lexer, cs);
return parser;
}
private static RegexSimpleParser regexpParserOn(Reader in, LinkedListTokenStream stream)
throws IOException {
ANTLRReaderStream cs = new ANTLRReaderStream(in);
RegexSimpleLexer lexer = new RegexSimpleLexer(cs);
LinkedListTokenSource source = (LinkedListTokenSource) stream.getTokenSource();
source.setDelegate(lexer);
// The AS3 grammar will see the initial '/' as an DIV (divide)
// token, and lookahead in the AS3Parser will have already
// grabbed references to that token in order to make it the
// startToken for various AST subtrees, so we can't just delete
// it. We therefore find the DIC token and change its type to
// match the regexp vocabulary, and then rewind the token stream
// so that this will be the first token that the
// SinpleRegexpParser will see.
LinkedListToken startMarker = (LinkedListToken) stream.LT(-1);
startMarker.setType(RegexSimpleParser.REGEXP_DELIMITER);
stream.seek(stream.index() - 1);
RegexSimpleParser parser = new RegexSimpleParser(stream);
parser.setTreeAdaptor(new LinkedListTreeAdaptor());
parser.setInput(lexer, cs);
return parser;
}
