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Wed, 24 February 2010 21:00

Eclipse User

Hi,

suppose I have a meta model where there are classes
B and C that extend a class A and another model with
a class D.

B has an attribute of type b and C has an attribute of type c.
Also, D has an attribute of type d.

I want to write an extension like this:

create D this AToD(A aa):
// If A is a B, set D.d to B.b,
// if A is a C, set D.d to C.c
;

At first I thought I could just write several extensions
with the same name for every class:

create D this AToD(B bb) and create D this AToD(C cc)

However, I get this exception:
org.eclipse.core.commands.common.NotDefinedException: Cannot get the
parent identifier from an undefined context.
org.eclipse.ui.edit.text.actionSet.presentation

Then I thought I could write an Extension like this:

create D this AToD(A aa):
// If A is a B, return BToD
// if A is a C, return CToD
;

and also two extensions like this:

create D this BToD(B bb):
this.setd(bb.b)
;

create D this CToD(C cc):
this.setd(cc.c)
;

Is there something like an 'instanceof' operator in xtend
so I can use the latter approach? Or maybe the first is the
right one and i'm just doing something wrong?

Regards,
Matthias

Re: [xtend] instanceof [message #516771 is a reply to message #516766]

Wed, 24 February 2010 20:06

Eclipse User

Matthias Schmeling schrieb:
> I want to write an extension like this:
>
> create D this AToD(A aa):
> // If A is a B, set D.d to B.b,
> // if A is a C, set D.d to C.c
> ;
>
> At first I thought I could just write several extensions
> with the same name for every class:
>
> create D this AToD(B bb) and create D this AToD(C cc)

Yes, that should work.

> However, I get this exception:
> org.eclipse.core.commands.common.NotDefinedException: Cannot get the
> parent identifier from an undefined context.
> org.eclipse.ui.edit.text.actionSet.presentation

It shouldn't have something to do with the extension.
Could you please file a bugzilla containing the stack trace and the example?

>
> Is there something like an 'instanceof' operator in xtend
> so I can use the latter approach?

Yes, it's: TypeName.isInstance(object)

Sven

--
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Re: [xtend] instanceof [message #517066 is a reply to message #516771]

Thu, 25 February 2010 20:11

Eclipse User

Hi Sven,

thank you for your reply. You are right, the exception seems to have
nothing to do with the extension. It's because it doesn't occur anymore.
If I find a way to reproduce it, I will file a bugzilla.

Regards,
Matthias

Sven Efftinge wrote:
> Matthias Schmeling schrieb:
>> I want to write an extension like this:
>>
>> create D this AToD(A aa):
>> // If A is a B, set D.d to B.b,
>> // if A is a C, set D.d to C.c
>> ;
>>
>> At first I thought I could just write several extensions
>> with the same name for every class:
>>
>> create D this AToD(B bb) and create D this AToD(C cc)
>
> Yes, that should work.
>
>> However, I get this exception:
>> org.eclipse.core.commands.common.NotDefinedException: Cannot get the
>> parent identifier from an undefined context.
>> org.eclipse.ui.edit.text.actionSet.presentation
>
> It shouldn't have something to do with the extension.
> Could you please file a bugzilla containing the stack trace and the
> example?
>
>>
>> Is there something like an 'instanceof' operator in xtend
>> so I can use the latter approach?
>
> Yes, it's: TypeName.isInstance(object)
>
> Sven
>

Re: [xtend] instanceof [message #517088 is a reply to message #516766]

Fri, 26 February 2010 03:40

Eclipse User

Is there another function to check if an attribute is of a certain type ?

I want to redefine types (creating an age type, which is an Integer), and I want to check for every non-basic type that I create for what basic type they come from (and print that type).

superType creates a Set of all superTypes, but I can't find how to verify what type is in it.

thanks.

[Updated on: Fri, 26 February 2010 05:17] by Moderator

Re: [xtend] instanceof [message #518106 is a reply to message #517088]

Wed, 03 March 2010 00:33

Eclipse User

Hi Maxime,

MaximeLecourt schrieb:
> Is there another function to check if an attribute is of a certain type ?

Do you mean xpand2::Type?

You can write something like:

my::Type.allProperties.select(e|e.returnType.isAssignableFro m(OtherType))

Sven

--
Need professional support for Xtext and EMF?
Go to: http://xtext.itemis.com
Twitter : @svenefftinge
Blog : blog.efftinge.de

Re: [xtend] instanceof [message #518135 is a reply to message #516766]

Wed, 03 March 2010 03:44

Eclipse User

No, I had troubles with the basics on metamodeling, but its solved now (I think).

But still, thanks for answering, that answer helps me for something else.

Regards
maxime

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