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xtext grammar for precision [message #1742892]

Thu, 08 September 2016 12:47

Sachin Samaram

Messages: 271
Registered: April 2016

Senior Member

Hi,

How to write xtext grammar in order to use '%' as precision?

I tried this :

Precision: precision=('%'|'%t') (int=INT|float=FLOAT);

terminal FLOAT returns ecore::EFloat: ('0'..'9')* '.' ('0'..'9')*;

terminal INT returns ecore::EInt: '0'..'9' ('0'..'9')*;

Example:
%t.2 rem = i / 7

but I am getting an error like no viable alternative at input '.2'

It works if I use terminal rules like:
Precision: (int=INT|float=FLOAT);

terminal FLOAT returns ecore::EFloat: ('%'|'%t')? ('0'..'9')* '.' ('0'..'9')*;

terminal INT returns ecore::EInt: ('%'|'%t')? '0'..'9' ('0'..'9')*;

But this is not expected because precision can be misused for normal cases also.

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