The Verification Corner - Specifications in Action with Spec#

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In this episode of The Verification Corner, Rustan Leino gives a demonstration of specifications in action. He builds a program that chunks strings into pieces, i.e. a chunker, in Spec#. During the demo, he shows the verifier, the developer, and the specifications fit together in the development cycle. Rustan Leino is a Principal Researcher in the Research in Software Engineering (RiSE) group at Microsoft Research.

The Verification Corner is a show on Software Verification Techniques and Tools. The show is produced by the Research in Software Engineering team (RiSE) , which coordinates Microsoft's research in Software Engineering in Redmond, USA.



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    The Discussion

    • User profile image

      That's a pretty impressive example. It makes clear how many possible bugs specifications can catch: a lot. It also makes me quite envious of Spec#. Hopefully these features will be incorporated into C# at some point in time; we do have Code Contracts for .Net but this syntax is so much better. It would also be very nice to be able to assign invariants to primitive type aliases, e.g.


      alias nat = int where nat >= 1;


      Maybe there's not that many use-cases for that feature though.


      Non-nullness annotations is another very hot feature.


      Also, since LINQ to Objects uses Dispose (as in IEnumerator extends IDisposable; the sole purpose of which is IO cleanup) can we then consider LINQ to Objects as impure and therefore not suitable for specifications?

    • User profile image

      Very nice, but I'd like to see the full postcondition for NextChunk. Perhaps, in your next episode, you could give an example of a postcondition containing, say, a quantified expression.

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