Tuesday, January 27, 2015

Clafer, ClaferIG, ClaferWiki, ChocoSolver, and ClaferChocoIG 0.3.8 Released

by Michał Antkiewicz

The Clafer compiler, Alloy-based instance generator, and wiki 0.3.8 are released on Hackage (clafer, claferIG, claferwiki). The Choco-based instance generator and multi-objective optimizer 0.3.8 is also released. Binary builds are available from Clafer Tools - Binary Distributions.

Major changes include:
  • Allowed having both super and reference parts of a clafer declaration. See pull request.
  • Changed the intersection operator from & to ** to be consistent with ++ and --.
  • Prepared for module system and behavioral Clafer extension.
  • Fixed bugs in HTML and Graph generators.
  • Replaced soft constraint (...) with assertion assert [...]. Soft constraints were never supported in any backend.
  • Phased out Alloy4.1. Alloy 4.2 is now used by default as a compiler mode, for output validation, and instance generation in ClaferIG.
  • The claferwiki.sh script can now run the wiki from sandbox when given the parameter --sandbox.
For detailed changes see pull requests: Clafer, ClaferIG, ClaferWiki

Tuesday, January 20, 2015

Explaining Clafer Semantics by Example

by Michał Antkiewicz

Learning a new language from abstract formal descriptions is hard when lacking strong mathematical background. In the attached presentation, I explain the semantics of Clafer in a simple and intuitive, and yet precise way. I focus on individual language constructs, show small model snippets, and explicitly write down instances of these models as sets and relations. I also explicitly evaluate expressions to show the mechanics of the language. The main goal is to illustrate the application of the abstract semantic rules to concrete cases. This way of presenting the semantics of a modeling language is complementary to the formal presentations.

PowerPoint Slide Show

Thursday, January 15, 2015

Behavioral Clafer 0.4.0 Preview Release

by Michał Antkiewicz

We are currently working on the implementation of an extension to Clafer for modeling the evolution of model instances over time: "behavioral Clafer". We published a preview release in Clafer Tools Binary Distributions.

Here's an example model of a PowerWindow system, which includes a feature model, an architecture model, a state machine, and positive and negative execution scenarios. The page is a HTML rendering of the source code in Clafer done by the extended behavioral Clafer compiler. The page was manually edited to add headers explaining the parts of the model.