Eclipse Community Forums: OCL » Map type support in OCL?

Home » Modeling » OCL » Map type support in OCL?(OCL language support for Map)

Map type support in OCL? [message #1797870]

Wed, 07 November 2018 11:57

Eclipse User

Is there an intention to add a Map type to OCL for the next OMG version or in Eclipse?
This would be very useful for developing software tools in OCL.

I have been using a partial implementation (similar to ATL's Map) for some time, here
are details of this & a Python library for it.

Attachment: ocl.py
(Size: 7.76KB, Downloaded 153 times)
Attachment: oclmap.pdf
(Size: 32.46KB, Downloaded 198 times)

Re: Map type support in OCL? [message #1797925 is a reply to message #1797870]

Thu, 08 November 2018 10:41

Eclipse User

Hi Kevin

Thank you for reposting your private communication.

[1] (Basic Map) identifies the addition of a prototype Map type to the Pivot-based Eclipse OCL over three years ago following discussion at OCL 2014. See the model at [4]

[2] (Map construction) was raised two weeks ago when it become clear that constructing a Map could be really tedious/inefficient.

[3] (Map iteration) was raised yesterday in response to your private communication preceding this forum posting.

I have done a little coding yesterday and today to see how iterators might work out.

[1] https://bugs.eclipse.org/bugs/show_bug.cgi?id=462721
[2] https://bugs.eclipse.org/bugs/show_bug.cgi?id=540353
[3] https://bugs.eclipse.org/bugs/show_bug.cgi?id=540884
[4] http://git.eclipse.org/c/ocl/org.eclipse.ocl.git/tree/plugins/org.eclipse.ocl.pivot/model/OCL-2.5.oclstdlib

---

The Eclipse OCL prototype Map was inspired by ATL and discussion with Frederic Jouault. Names, such as "at" rather than "get", were revised to be consistent with side effect free OCL rather than imperative Java. There is therefore considerable commonality with your ideas. Perhaps a notable difference is that Map.at returns invalid just like Sequence.at for index-out-of-bounds, which is consistent and necessary since keys and/or values may be null.

Despite comments from many authors, including myself, that a Set of Tuple can be a Map. It cannot. Uniqueness is on the key not the tuple. Consequently an asSet() implementation is dangerous.

Consistency is pushing me towards collectNestedBy for the simple key to f(key) Map constructor and collectBy for the key to flattened(f(key)) MultiMap constructor. I'm not happy with the 'spelling'.

"inverse" is certainly interesting.

"count" probably needs to be the rather degenerate key by default and "countValue"

Feel free to add comments to the Bugzillas.

Regards

Ed Willink

Re: Map type support in OCL? [message #1798639 is a reply to message #1797925]

Wed, 21 November 2018 09:09

Eclipse User

Hi

The improved Map functionality discussed in [2], [3] is now available as [4]. The N&N at [1] has some minimal examples.

Regards

Ed Willink

[1] https://wiki.eclipse.org/OCL/New_and_Noteworthy/2018-12
[2] https://bugs.eclipse.org/bugs/show_bug.cgi?id=540353
[3] https://bugs.eclipse.org/bugs/show_bug.cgi?id=540884
[4] http://www.eclipse.org/modeling/download.php?file=/modeling/mdt/ocl/downloads/drops/6.6.0/I201811211206/mdt-ocl-Update-I201811211206.zip

Previous Topic:	Initialise Map in OCL
Next Topic:	a derived property

Goto Forum:

-=] Back to Top [=-

Current Time: Tue Jul 15 10:39:36 EDT 2025

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter