parser-generator

I am attempting to get a basic ECMAScript parser working, and found a complete ANTLR grammar for ECMAScript 3 , which appears to compile ok and produces the appropriate Lexer/Parser/Walker Java files. (Running inside ANTLR IDE plugin for Eclipse 3.5) However, when actually trying to use it with some simple test code (following guide on ANTLR wiki ), it just hangs when trying to create the parser: CharStream MyChars = new ANTLRFileStream(FileName); // FileName is valid ES3Lexer MyLexer = new ES3Lexer(MyChars); CommonTokenStream MyTokens = new CommonTokenStream(MyLexer); MyTokens.setTokenSource

What is the best way to handle multiple Flex/Bison parsers inside a project? I wrote a parser and now I need a second one in the same project. So far in the third section of parser1.y I inserted the main(..) method and called yyparse from there. What I want to obtain is having two different parsers ( parser1.y and parser2.y ) and be able to use them from an external function (let's assume main in main.cpp ). Which precautions should I use to export yyparse functions outside .y files and how should I handle two parsers? PS. I'm using g++ to compile but not the C++ versions of Flex and Bison and

I'm dusting off an old project of mine which calculates a number of simple metrics about large software projects. One of the metrics is the length of files/classes/methods. Currently my code "guesses" where class/method boundaries are based on a very crude algorithm (traverse the file, maintaining a "current depth" and adjusting it whenever you encounter unquoted brackets; when you return to the level a class or method began on, consider it exited). However, there are many problems with this procedure, and a "simple" way of detecting when your depth has changed is not always effective. To make

I have seen many ANTLR grammars that use whitespace handling like this: WS: [ \n\t\r]+ -> skip; // or WS: [ \n\t\r]+ -> channel(HIDDEN); So the whitespaces are thrown away respectively send to the hidden channel. With a grammar like this: grammar Not; start: expression; expression: NOT expression | (TRUE | FALSE); NOT: 'not'; TRUE: 'true'; FALSE: 'false'; WS: [ \n\t\r]+ -> skip; valid inputs are ' not true ' or ' not false ' but also ' nottrue ' which is not a desired result. Changing the grammar to: grammar Not; start: expression; expression: NOT WS+ expression | (TRUE | FALSE); NOT: 'not';

I need to write a compiler. It's homework at the univ. The teacher told us that we can use any API we want to do the parsing of the code, as long as it is a good one. That way we can focus more on the JVM we will generate. So yes, I'll write a compiler in Java to generate Java. Do you know any good API for this? Should I use regex? I normally write my own parsers by hand, though it is not advisable in this scenario. Any help would be appreciated. Regex is good to use in a compiler, but only for recognizing tokens (i.e. no recursive structures). The classic way of writing a compiler is having a