Eclipse Community Forums: OCL

Help

Home

Home » Modeling » OCL » OCL and Xtext (OCL statement for primitive datatypes)

Show: Today's Messages :: Show Polls :: Message Navigator

OCL and Xtext [message #1257619]

Wed, 26 February 2014 16:30

Günther Fiedler

Messages: 21
Registered: February 2013

Junior Member

Hello!

I´m currently working on a semantic validation of my Xtext grammar by using OCL.

In my grammar i made the initialization of attributes optional.

But i still allow something like

public boolean flag = 5;

Therefore i was trying to write an OCL-Statement.

context Variable_Base inv DataTypeValueInt ('Type mismatch'):
self.param.paramType.datType.oclAsType(DataType).datType = 'int' implies self.value.val.oclIsTypeOf(IntLiteral)

This Statement works fine checking the values of the attribute. The problem now is, that the initialization of an attribute isn´t optional any more.

Thanks in advance,
Günther

Report message to a moderator

Re: OCL and Xtext [message #1257711 is a reply to message #1257619]

Wed, 26 February 2014 18:16

Ed Willink

Messages: 7655
Registered: July 2009

Senior Member

Hi

If you want it to be optional you shouldn't navigate on from the value.

You must guard it just as you would a null in Java.

.... implies self.value.val.oclIsTypeOf(IntLiteral)

should perhaps be

.... implies self.value<> null implies
self.value.val.oclIsTypeOf(IntLiteral)

It is likely that OCL 2.5 will introduce the safe navigation operator
allowing

.... implies self.value?.val.oclIsTypeOf(IntLiteral)

Regards

Ed Willink

On 26/02/2014 16:30, Günther Fiedler wrote:
> Hello!
>
> I´m currently working on a semantic validation of my Xtext grammar by
> using OCL.
>
> In my grammar i made the initialization of attributes optional.
>
> But i still allow something like
> public boolean flag = 5;
>
> Therefore i was trying to write an OCL-Statement.
> context Variable_Base inv DataTypeValueInt ('Type mismatch'):
> self.param.paramType.datType.oclAsType(DataType).datType = 'int'
> implies self.value.val.oclIsTypeOf(IntLiteral)
>
> This Statement works fine checking the values of the attribute. The
> problem now is, that the initialization of an attribute isn´t optional
> any more.
>
> Thanks in advance,
> Günther

Report message to a moderator

Re: OCL and Xtext [message #1258316 is a reply to message #1257711]

Thu, 27 February 2014 09:04

Günther Fiedler

Messages: 21
Registered: February 2013

Junior Member

Hi Ed,

thank you very much, it works perfectly fine!

I managed to find another solution:

inv DataTypeValueInt ('Assigned value is not Integer'):
if self.param.paramType.datType.oclAsType(DataType).datType = 'int' and ((self.value <> null and self.value.val.oclIsTypeOf(IntLiteral)) or self.value = null) then
true
else
if self.param.paramType.datType.oclAsType(DataType).datType <> 'int' then
true
else
false
endif
endif

But your´s is way easier, thank you again for the lesson!

Kind regards,
Günther

Report message to a moderator

Previous Topic:	USE_TYPE_CACHES and DYNAMIC_DISPATCH break basic OCL operations?
Next Topic:	Enum value not recognized?

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

]

Current Time: Fri Apr 19 03:28:16 GMT 2024

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter