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Problem with multiple alternatives [message #1775888]

Tue, 07 November 2017 16:08

Pedro Sánchez

Messages: 4
Registered: October 2017

Junior Member

Hi All,

Many days struggling with an error I am not able to solve.

A simplification of my grammar where the error is:
-----------------------------------------------
Enums: name=ID '::=' (r+=EnumElem)+;

EnumElem: name=ID;

FQN: ID ("." ID)* ;

Vars: Type name=ID (':=' value=Primitive_Value)? ;

Param: name=ID ;

VarPar: Vars | Param ;

SuperVarPar:
v=[VarPar] | e=[EnumElem|FQN]
;

PerVarParam: v=SuperVarPar;
-----------------------------------------------

warning(200): ../org.xtext.example.trprograms/src-gen/org/xtext/example/mydsl/parser/antlr/internal/InternalTR.g:735:2: Decision can match input such as "RULE_ID" using multiple alternatives: 1, 2
As a result, alternative(s) 2 were disabled for that input
error(201): ../org.xtext.example.trprograms/src-gen/org/xtext/example/mydsl/parser/antlr/internal/InternalTR.g:735:2: The following alternatives can never be matched: 2

I need to have access to both Vars, Params and Enums in SuperVarPar but the part with "e=[EnumElem|FQN]" gives the previous error.

I have tried many other combinations without error but not recognizing enums elements. FQN was added to allow referencing enums elements (it works fine in other part of the grammar).

Any idea??
(enclosed also the full grammar)

I would need a good tutorial to learn the basics of xText to avoid problems like this one but reading the official documentation is not enough for me.... :(

Many thanks in advance.

Attachment: grammar org3.docx
(Size: 66.99KB, Downloaded 84 times)

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Re: Problem with multiple alternatives [message #1775896 is a reply to message #1775888]

Tue, 07 November 2017 19:58

Christian Dietrich

Messages: 14665
Registered: July 2009

Senior Member

can you please share the reproducible grammar in a usable form. docx is not

Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

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Re: Problem with multiple alternatives [message #1775907 is a reply to message #1775896]

Wed, 08 November 2017 08:01

Pedro Sánchez

Messages: 4
Registered: October 2017

Junior Member

Hi Christian,

Many thanks for your help.

Enclosed the xtext file. I am not sure if you need the whole project or not...

Look forwardyour reply.

Pedro.
Spain