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Home » Modeling » TMF (Xtext) » Xtext multiple parameter to a method possibility(Want to know is it possible to provide a production rule and a terminal rule as a possible parameter to a method together.)

Xtext multiple parameter to a method possibility [message #1758074]

Thu, 23 March 2017 05:53

Eclipse User

Please find the xtext grammar sample attached. I have a following rule.

SomeFunction:
name=('addDays' | 'addWeeks' | 'addYears') '(' value=NUMBER ')';

terminal NUMBER returns ecore::ELong:
'-'?('0'..'9')+;

All other things are defined and working fine. What I want to change is that to add a production rule as a possible alternative in the parameters of SomeFunction , which is as follows -

SomeFunction:
name=('addDays' | 'addWeeks' | 'addYears') '(' value=(NUMBER | ProductionRule_A) ')';

I'm getting an error which is as follows - Cannot find type for 'NUMBER | ProductionRule_A'.

Please guide me whether it's possible to do so. IF not why. IF yes how can i do this.

Re: Xtext multiple parameter to a method possibility [message #1758099 is a reply to message #1758074]

Thu, 23 March 2017 10:20

Eclipse User

is ProductionRule_A a parser rule. if so this makes no sense: a attribute cannot be ob a simple and a complex type at the same time.
maybe you want to

.... value=(NumberLiteral | ProductionRule_A)

NumberLiteral: number=NUMBER;

Re: Xtext multiple parameter to a method possibility [message #1758992 is a reply to message #1758099]

Wed, 05 April 2017 02:06

Eclipse User

Yes ProductionRule_A is a parser rule. Is it possible/allowed to be used like this ?
Using your suggestion, it fails in the content assist, for e.g. when I'm about to complete the ProcutionRule_A , the model comes out to be null in my custom proposal provider class, in the completeXXXXX method. How to deal with that ?
Additionally i wanted to enquire or you can guide me to some resource that clearly states that whether or not we can/cannot use simple and complex type attributes in a method parameters list in Xtext using the grammar.

[Updated on: Wed, 05 April 2017 02:08] by Moderator

Re: Xtext multiple parameter to a method possibility [message #1758995 is a reply to message #1758992]

Wed, 05 April 2017 02:47

Eclipse User

can you please give a complete hello world sample grammar with failing CA

Re: Xtext multiple parameter to a method possibility [message #1758999 is a reply to message #1758995]

Wed, 05 April 2017 03:31

Eclipse User

Yes I'll just share it in my next reply

Re: Xtext multiple parameter to a method possibility [message #1759000 is a reply to message #1758995]

Wed, 05 April 2017 03:31

Eclipse User