Program errors are hard to detect and are costly both to programmers who spend significant efforts in debugging, and for systems that are guarded by runtime checks. Static verification techniques have been applied to imperative and object-oriented languages, like Java and C#, but few have been applied to a higher-order lazy functional language, like Haskell. In this paper, we describe a sound and automatic static verification tool for Haskell, that is based on contracts and symbolic execution. Our approach is modular and gives precise blame assignments at compile-time in the presence of higher-order functions and laziness.
Errata. In Figure 2, in the right hand side of rule [E-match1], the ai and xi should both have vector arrows over them.
- Slides (PDF) of a talk given at the Midlands Graduate School Christmas Lectures, 2007.