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[EVL] conditional syntax [message #1308921]

Tue, 22 April 2014 11:02

Shrikanth NC

Messages: 31
Registered: February 2014

Member

Say I have a rough emfatic file like this,

class Block {
}

//Node
class A extends Block { }

//Node
class B extends Block { }

//Node
class C extends Block { }

//Link
class connect{

ref Block target;

ref Block source;

}

All i want to validate in EVL is ...

context connect

if ( source instanceof A & target instanceof B ) {

message : "This is discouraged!"

}
else if ( source instanceof C & target instanceof B ) {

message : "This is encouraged!"

}

Kindly help me with the evl syntax!

Thanks,
Shrikanth NC

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Re: [EVL] conditional syntax [message #1308922 is a reply to message #1308921]

Tue, 22 April 2014 11:05

Dimitris Kolovos

Messages: 2163
Registered: July 2009
Location: York, UK

Senior Member

Hi,

Please refer to the isTypeOf/isKindOf operations in the Epsilon book.

Cheers,
Dimitris

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Re: [EVL] conditional syntax [message #1308949 is a reply to message #1308922]

Tue, 22 April 2014 11:24

Shrikanth NC

Messages: 31
Registered: February 2014

Member

It does work as intended. ( when i use either isKindOf/isTypeOf )

But there is a side effect.

Like if I connect A to A or B to B or A to C

then in this case both messages are shown with error!

My Evl below,

context connect{

constraint DiscouragedUsage1{

check : self.source.isKindOf(A) and self.target.isKindOf( B)
message : "This is discouraged usage 1!"

}

constraint DiscouragedUsage2{

check : self.source.isKindOf(B) and self.target.isKindOf( C)
message : "This is discouraged usage 2!"

}

}

Thanks,
Shrikanth NC

[Updated on: Tue, 22 April 2014 11:26]

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Re: [EVL] conditional syntax [message #1309039 is a reply to message #1308949]

Tue, 22 April 2014 12:33

Dimitris Kolovos

Messages: 2163
Registered: July 2009
Location: York, UK

Senior Member

Hi,

Could you please put together a minimal example [1] I can use to reproduce this?

Cheers,
Dimitris

[1] http://eclipse.org/epsilon/doc/articles/minimal-examples/

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Re: [EVL] conditional syntax [message #1310259 is a reply to message #1309039]

Wed, 23 April 2014 05:01

Shrikanth NC

Messages: 31
Registered: February 2014

Member

mailed to epsilon.devs@gmail.com <epsilon.devs@gmail.com>;

Thanks,
Shrikanth NC

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Re: [EVL] conditional syntax [message #1312444 is a reply to message #1310259]

Thu, 24 April 2014 09:42

Dimitris Kolovos

Messages: 2163
Registered: July 2009
Location: York, UK

Senior Member

Hi,

Apologies for the slow response. In EVL, validation errors are produced when check condition are *not* satisfied. As such, you'll need to express your constraints as follows:

context Connect{

constraint DiscouragedUsage2{

check : not (self.source.isKindOf(A) and self.target.isKindOf( B ))

message : "This is discouraged usage 1!"

}

constraint DiscouragedUsage1{

check : not (self.source.isKindOf(A) and self.target.isKindOf( C ))

message : "This is discouraged usage 2!"

}

}

Cheers,
Dimitris

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