Re: question on directive <commit> and subrules

On Donnerstag, Februar 7, 2002, at 02:14  Uhr, damian wrote:

> Usually by "anchoring" the end of the match. That might be:
>
>   myrule: 'stuff' mysubrule(?) ...!ID

it seems necessary to return a { 1 } here, as the rule
fails otherwise, presumably because of the negative lookahead:

   myrule: 'stuff' mysubrule(?) ...!ID { 1 }

>   mysubrule: ID <commit> '[' ']'
>            | <error?> <reject>
>
> or
>
>   myrule: 'stuff' mysubrule(?) /\s*\Z/
>
>   mysubrule: ID <commit> '[' ']'
>            | <error?> <reject>
>
>
> or whatever addition confirms that there really wasn't anything else
> after 'stuff'.

another option would be the use of a rulevar:

   myrule : <rulevar: local $failed>
   myrule : 'stuff' mysubrule(?) <reject:$failed>

   mysubrule: ID <commit> '[' ']'
            | <error?> { $failed++ }

this way you don't have to specify a potentially complex negative
lookahead, and the method works over several levels of subrules
as well.

marcel