[Haskell] ANN: witness 0.1, open-witness 0.1, "Witnesses and Open Witnesses"

Don Stewart dons at galois.com
Mon Aug 18 13:12:01 EDT 2008

> witness 0.1
> A witness is a value that witnesses some sort of constraint on some list 
> of type variables. This library provides support for simple witnesses, 
> that constrain a type variable to a single type, and equality witnesses, 
> that constrain two type variables to be the same type. The library also 
> provides classes for representatives, which are values that represent types.

> open-witness 0.1
> Open witnesses (type IOWitness) are simple witnesses that can witness to 
> any type. However, they cannot be constructed, they can only be 
> generated in certain monads:

> Hackage: 
> <http://hackage.haskell.org/cgi-bin/hackage-scripts/package/open-witness>
> Source: <http://code.haskell.org/open-witness/>

You can find these packages for your local Arch Linux distribution,


Come on Debian! :)

-- Don

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