[antlr-interest] Predicate Syntax Problem

[Terence Parr]

On Jan 11, 2007, at 11:34 PM, Bill Venners wrote:

> Hello,
>
> I am not sure how to add a predicate to one element of an OR  
> expression in ANLTR 3.
>
> passedDecl
>     :    'not-null'? ('byte' | 'short' | 'int' | 'long' | 'boolean'  
> | 'float' | 'double'
>          | 'char' | ID_UP )^ { isTypeName($ID_UP.getText()) }?
>          ID_DOWN { isVarName($ID_DOWN.getText()) }?
>     ;
>
> This is apparently valid grammar syntax, but the $ID_UP doesn't  
> work. I get:
>
> com/artima/view/ViewParser.java:497: cannot find symbol
> symbol  : variable $ID_UP
> location: class com.artima.view.ViewParser
>             if ( !( isTypeName($ID_UP.getText()) ) ) {
>
> I am unable to find any help in the documentation I can find. Can  
> someone help me understand what I should do here? What I'd like to  
> accomplish is to kill the parse if the ID_UP variable returns false  
> when passed to isTypeName().

Hi Bill,

Have you tried the latest jar in file sharing area?  It should fix  
lots of these.  Do you want the {...}? to validate input or  
disambiguate?  If the latter, they should go on the left edge. :)

Ter