[antlr-interest] Automatic lists

[Jim Idle]

> -----Original Message-----
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
> bounces at antlr.org] On Behalf Of Ben Corne
> Sent: Tuesday, May 17, 2011 6:44 AM
> To: antlr-interest at antlr.org
> Subject: Re: [antlr-interest] Automatic lists
>
> Found it in the definitive antlr guide: adding a ? behind $docs did the
> trick.

Actually you need to correct the cardinality of the list, not an element:

$docs* - 0 or more docs
$docs+ - 1 ot more docs
$docs  - 1 doc (no list)
$docs? - 0 or 1 docs (no list)

So, where you are using += you need to use the list versions of the
references.

Jim

> 2011/5/17 Ben Corne <ben.corne at gmail.com>
>
> > Hi
> >
> > I'm trying to create a rule looking like this:
> > ==================================
> > statement
> >   : ( docs+=documentation )*
> >   ( def=definition -> ^(AGSTATEMENT $docs $def)  |
> tdef=typedefinition
> > -> ^(AGSTATEMENT $docs $tdef)
> > | imp=imports -> ^(AGSTATEMENT $docs $imp)
> >    // TODO: (variable EQL) => varassignment
> >    // TODO: (assignment) => assignment  | exp=expression ->
> > ^(AGSTATEMENT $exp $docs)
> >   ;
> > ==================================
> >
> > This rule should add a bunch of documentation constructs to each type
> > of statement. Testing with at least one documentation per statement,
> > everything works as expected.
> >
> > Now the problem is that when I test statements without any
> > documentation added to a statement, the ANTLRworks debugger seems to
> > stop after the first such statement, refusing to go parse the
> folowing statements.
> >
> > I suspect that it is because the $docs variable is never initialized
> > since nothing is added. How should I fix this?
> >
> > Regards
> > Ben C.
> >
>
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