[antlr-interest] AST for repeated occurrences of binary operators

[David-Sarah Hopwood]

Jim Idle wrote:
> David-Sarah Hopwood wrote:
>> Caetano Sauer wrote:
>>> What I want is (OR a b c).
>>
>> I think that will be produced by:
>>
>>   orExpr : andExpr (^OR andExpr (OR! andExpr)*)?;
>
> expr : ae+=andExpr (OR ae+=andExpr)* -> ^(OR $ae+) ;

That isn't what the poster asked for: it will produce '(OR a)' when
the input is an andExpr, whereas what I posted above should produce
just 'a', if I haven't made a mistake.

> But usually that isn't the best way to organize the tree and:
> 
> expr : andExpr (^OR andExpr)*;
> 
> Is what is needed.

I agree. For binary operators, a binary AST is easier to deal with.

-- 
David-Sarah Hopwood  ⚥  http://davidsarah.livejournal.com

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