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Bug 321011

Summary:	Unexpecter filter signature
Product:	[Modeling] Acceleo	Reporter:	Ed Willink <ed>
Component:	Core	Assignee:	Project Inbox <acceleo-inbox>
Status:	CLOSED FIXED	QA Contact:
Severity:	normal
Priority:	P3	CC:	laurent.goubet
Version:	unspecified
Target Milestone:	---
Hardware:	PC
OS:	Windows XP
Whiteboard:

Description Ed Willink

2010-07-27 09:32:58 EDT

Surely filter just selects collection elements, so it does not change the collection kind, therefore Bag::filter => Bag.

This is particularly tricky given the lack of let diagnosis so

[let aFilteredBag : Bag(X) = anUnfilteredBag(X)]

gets no diagnosis.

Equally a filtered Set is surely still a Set.

Comment 1 Laurent Goubet

2010-07-27 09:37:14 EDT

Sorry, but I couldn't understand either the issue or the expected resolution ... Could you elaborate on what Acceleo gets wrong and what you expect it to do?

Comment 2 Ed Willink

2010-07-27 11:55:42 EDT

I would expect

Collection(T)::filter(Classifier) : Collection(T)
Bag(T)::filter(Classifier) : Bag(T)
OrderedSet(T)::filter(Classifier) : OrderedSet(T)
Sequence(T)::filter(Classifier) : Sequence(T)
Set(T)::filter(Classifier) : Set(T)

(Classifier is what might replace OclType one day).

Comment 3 Laurent Goubet

2010-07-28 03:24:07 EDT

This is already what Acceleo does, filter doesn't alter collection types. What you ask us to do is to add explicitely the Bag::filter() : Bag and all three others instead of only Collection::filter() : Collection?

Comment 4 Ed Willink

2010-07-28 03:37:06 EDT

I did

[let aFilteredBag : Bag(X) = anUnfilteredBag(X)]

and aFiteredBag was empty.

I did

[let aFilteredBag : Sequence(X) = anUnfilteredBag(X)]

and aFiteredBag was not empty!

This suggests that the signature of filter is as documented

Collection::filter() : Sequence

Comment 5 Laurent Goubet

2010-07-28 03:52:04 EDT

I can't figure out why you're talking about the "filter" operation with what you write as expressions. I could only figure the issue (well, more "deduce" as I am not sure this is your actual problem) with your last comment about a documentation issue on the filter operation.

There's indeed an implementation error on my side, I always return a Sequence from the filter operation... which provoked the documentation error as I am not the one who wrote it.

Comment 6 Laurent Goubet

2010-07-30 09:36:02 EDT

filter should no longer implicitly cast everything to a Sequence. The fix has been committed on HEAD and will be available for the next build.

Comment 7 Laurent Goubet

2011-08-18 04:22:20 EDT

Closing our "resolved" and "verified" bugs.