[antlr-interest] problem with rules in tree parsers, is it a bug or is it normal ?

[Anthony Brenelière]

In a tree parser,
I have the following rules

entOrSet
	:	(entity)=> entity
	|	(set)=> set
;

entity
	:	#( R_ENT entityComponentList )
;

it compiles well, and there is no non-determinism
but it is not able to recognize the token R_ENT whereas it should.

I have the following message error :

<AST>: unexpected AST node: [entity]
..each time an entity is found. ("[entity]" is the text for the token
R_ENT)

BUT..

When I change the entOrSet rule to:

entOrSet
	:	(entity)=> entity
	//	|	(set)=> set (this alternative is suppressed)
;

then everything works fine ! Then 'entity' rule is perfectly matched.
( but of course, i cannot have 'sets' sentences in my document )

Any idea about how to solve this problem ?


Cordially,
Anthony


 

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