[antlr-interest] Operator tree construction in rewrite syntax

[Terence Parr]

On Apr 15, 2008, at 12:41 PM, Gavin Lambert wrote:

> At 04:20 16/04/2008, Marko Simovic wrote:
>> also, while we're on the subject, what about a rewrite syntax of  
>> this one:
>>
>> unary: (UnaryOp^)? something;
>
> That one's simpler, because there aren't any loops (so no need to  
> generate multiple trees):
>
> unary
>  :  UnaryOp s1=something -> ^(UnaryOp $s1)
>  |  s2=something -> $s2
>  ;

or

unary
	: UnaryOp something -> ^(UnaryOp something)
	| something
	;

in 2nd alt, ANTLR just adds to tree.

Ter