[antlr-interest] ambigous lexer tokens

[Gavin Lambert]

At 22:20 28/06/2007, Wincent Colaiuta wrote:
 >Well, here's one (untested) idea: one way might be to modify 
your
 >WS rule to increment a "column" counter whenever a run of spaces 

 >is seen; you'd have to set up the column counter in your
 >@lexer::members section (exactly how you set up and initialize
 >that variable is dependent on your target language):
 >
 >   WS : ' '+ { column++; };

Actually, I'm pretty sure that v3 tracks the column for you, so 
there's no need to do it manually.  How you get hold of it varies 
by target language, though, but it's usually a property/field of 
the lexer class, I think.

In fact I vaguely remember there being an example script for a 
column-sensitive language (Fortran, maybe?  Not sure) either in 
the v3 examples bundle or on the Wiki.

(Sorry for being so vague; it's after midnight.)