[news.eclipse.modeling.gmt] Re: [Epsilon][EVL] Possible Bug with collect

[Dimitrios Kolovos <dskolovos@xxxxxxxxx>]

Hi Andrew,

Each constraint in a context must be named uniquely. In your case the 
2nd and 3rd constraint have the same name (CheckChildOperations), and 
therefore the latter shadows the prior.

A couple of comments: you don't need to use the -> operator; the . does 
the same (e.g. you can write x.collect(a|a>0) instead of 
x->collect(...)). Also I'm not sure if the self->collect(...) code in 
the last constraint makes sense as self is an instance of Entity and 
self->collect(b|b.operations) will return a sequence of sequences of 
operations (e.g. Sequence{Sequence{op1,op2,op3}} ).

Cheers,
Dimitrios

Andrew Lawson wrote:
> I may have discovered a bug which occurs when comparing collections.  I 
> first ran the following validation file...
>
> context SimpleClass!Entity {
>
>
> constraint CheckingParentExists {
>
> check : self.Child = true implies self.parent-> size = 1
>
> message : 'There is no parent for ' + self.classname
>
> }
>
>
> constraint CheckChildOperations {
>
> guard: self.Child = true
>
>
> check : false
>
>
> message : self.parent.operations->collect(s| s.name) + 'does not have the 
> correct operations' + self.operations->collect(b|b.name)
>
>
> }
>
> ..which as you would expect returned: " first collection" does not have the 
> correct operations "second collection"
>
>
> However when I add in a third constraint which should compare the two 
> collections (as can be seen below) there is no validation output not even to 
> the constraint where the check is set to false.  Is this a bug or am I doing 
> something incorrectly?  [This used to work correctly]
>
> context SimpleClass!Entity {
>
>
> constraint CheckingParentExists {
>
> check : self.Child = true implies self.parent-> size = 1
>
> message : 'There is no parent for ' + self.classname
>
> }
>
>
> constraint CheckChildOperations {
>
> guard: self.Child = true
>
>
> check : false
>
>
> message : self.parent.operations->collect(s| s.name) + 'does not have the 
> correct operations' + self.operations->collect(b|b.name)
>
>
> }
>
>
> constraint CheckChildOperations {
>
> guard: self.Child = true
>
>
> check : self->collect(b|b.operations).includesAll( self.parent->collect(s| 
> s.operations ))
>
>
> message : self.classname + 'does not have the correct operations'
>
>
> }
>
>
>
> }