[antlr-interest] Search free text form for special tags grammar

Gavin Lambert antlr at mirality.co.nz
Mon Sep 10 03:15:19 PDT 2007


At 21:45 10/09/2007, Ronald Haring wrote:
>Could you enlighten me a bit. What is a lexer only rules grammar? 
>And how can I filter this?

A lexer-only grammar is one that starts with "lexer grammar" 
instead of just "grammar" and contains only lexer rules (ie. start 
with a capital letter, use characters as input, and tokens as 
output).

A filtering lexer is one with "filter=true" in the options.  When 
you specify that it changes the matching rules so that it doesn't 
need to consume every input character -- if it finds something it 
can't deal with then it skips that character and tries again.

There should be some examples around in the wiki, in the examples 
zipfile, and in the book.



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