[antlr-interest] All choices need a predicate?

[James Ladd]

Hi All,

I have a rule with multiple choices.

Do I have to add a predicate to all choices or can I add just the predicates
that I want, ie: leaving the more complicated choice without a predicate?

For example:

primary returns [Primary n]
    :    ('(') => l = '(' expression {$n = new PrimaryExpression($expression.n, $l.line);} ')'
    |    (NAME) => variable {$n = $variable.n;}
    |    (OPEN_BLOCK) => block {$n = $block.n;}
    |    literal {$n = $literal.n;}
    |    ('{') => array {$n = $array.n;}
    ;


Also, is it possible to add multiple choices to a predicate?

eg: ( this | that | thing ) => xxxx

Rgs, James.