[antlr-interest] Token stream filter

[Ric Klaren]

On Wed, Jun 02, 2004 at 03:37:15PM +0100, Anthony Youngman wrote:
> If I don't want to eat up the newline at the end, is the following
> likely to be a good/sensible parser rule?
> 
> commentst : REMARK ( (LA(1) != newline) => . )* ;
> 
> in other words, having found a REMARK, eat everything up to but not
> including the next newline. Or is LA a lexer-only thing as well?

That one is a bit inefficient due to an exception per character:

This is a dirty one but it works:

comment: REMARK ( { if( LA(1) == NEWLINE ) break; } : . )* ;

Tip: read the generated code.

Cheers,

Ric
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