[antlr-interest] rule, that consider token, follow the match token

[Bart Kiers]

On Thu, Jun 28, 2012 at 1:20 PM, Andrei Plet <andrei.plet at empolis.com>wrote:

> ...
> OP_AND : ('A'|'a') ('N'|'n') ('D'|'d');
> TEXT   : ('a'..'z'|'A'..'Z')+;
> PLUS   : '+';
>
> The rule OP_AND should match only, if after the input 'and' isn't a '+', so
>
> 'and'  --> should match rule OP_AND
> 'and+' --> should match 2 rules: the rule TEXT 'and' and rule PLUS '+'
>
>
I wouldn't do that in the lexer, but something like this instead:

OP_AND : ('A'|'a') ('N'|'n') ('D'|'d');
TEXT   : ('a'..'z'|'A'..'Z')+;
PLUS   : '+';

any_text : OP_AND | TEXT;
add_expr : any_text PLUS any_text;

Regards,

Bart.