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Variable declaration [message #899570]

Wed, 01 August 2012 13:25

Laigle jérôme

Messages: 26
Registered: August 2012

Junior Member

Hi,

I'm working on a DSL where it should be possible to differ between a declaration of a element and the definition of a element. For example:

dcl a%=10
dcl b% = 42
a = 12
b=30
b=a

So, I've started with the following construct

VariableName:
name=ID type=Type
;

VariableDeclaration :
'dcl' variableName=VariableName

;
VariableReference:
variableName=[VariableName|ID]
;

VariableAssignment:
variable=[VariableReference] '=' value=VariableValue
;

VariableValue:
{VariableValue}
(variableReference =VariableReference)?
//(value=Value)?
(value=NUMBER)?
;

whereas Type refers to my defined types. I've thought it might be an idea to use cross references like in the following fragment

VariableDef:
name=[VariableDeclaration] '=' INT;

But that's not working and I doubt that this is the right way. I'm new to Xtext and so this question might be quite stupid. Maybe somebody has an idea or can point me into the right direction? Thanks in advance!

Best regards,
Jérôme

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Re: Variable declaration [message #899573 is a reply to message #899570]

Wed, 01 August 2012 13:36

Henrik Lindberg

Messages: 2509
Registered: July 2009

Senior Member

Use:

VariableDeclaration :
'dcl' name=VariableName ;

since references use the feature "name" by default.

Regards
- henrik

On 2012-01-08 15:25, Laigle jérôme wrote:
> Hi,
>
> I'm working on a DSL where it should be possible to differ between a
> declaration of a element and the definition of a element. For example:
>
> dcl a%=10 dcl b% = 42 a = 12 b=30
> b=a
>
> So, I've started with the following construct
>
> VariableName:
> name=ID type=Type
> ;
>
> VariableDeclaration :
> 'dcl' variableName=VariableName
>
> ;
> VariableReference:
> variableName=[VariableName|ID]
> ;
>
> VariableAssignment:
> variable=[VariableReference] '=' value=VariableValue ;
>
> VariableValue:
> {VariableValue}
> (variableReference =VariableReference)? //(value=Value)?
> (value=NUMBER)?
> ;
>
> whereas Type refers to my defined types. I've thought it might be an
> idea to use cross references like in the following fragment
>
> VariableDef:
> name=[VariableDeclaration] '=' INT;
>
> But that's not working and I doubt that this is the right way. I'm new
> to Xtext and so this question might be quite stupid. Maybe somebody has
> an idea or can point me into the right direction? Thanks in advance!
>
> Best regards,
> Jérôme

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Re: Variable declaration [message #899604 is a reply to message #899573]

Wed, 01 August 2012 14:46

Laigle jérôme

Messages: 26
Registered: August 2012

Junior Member

thanks for the quick reply.

VariableDeclaration :
'dcl' name=VariableName ;

this is better because it fixed my problem with generate xtext artifact

but i do test with xtend in parallel and test no working

My test:
@Test
def void testSegmentNumVariableDeclaration()
{
val compilationUnit =
'''
program MyProgramme
segment 0
dcl maVariable%
maVariable=3

eseg 0
end
'''.parse
val segment = getProgrammeSegment(compilationUnit,0)
val variableName1=getProgrammeSegmentVariableDeclaration(compilationUnit,0,0)
Assert::assertNotNull(variableName1.type)
val num= variableName1.type
Assert::assertNotNull(num)
Assert::assertTrue(num instanceof NumericType)
val numericType= num as NumericType
Assert::assertEquals("maVariable", variableName1.name)
Assert::assertNotNull(numericType)

val instruction= segment.instructions.get(1)
Assert::assertNotNull(instruction)
Assert::assertTrue(instruction instanceof VariableAssignment)
val variableAssignment=instruction as VariableAssignment
Assert::assertEquals(3, variableAssignment.value)

}
the value of variableAssignment is null i don't understand why?

eror in the test :

junit.framework.AssertionFailedError: expected:<3> but was:<abal.language.impl.VariableValueImpl@4feaf536 (value: null)>

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