[Haskell-cafe] ANN: wizards-1.0: A High level, generic library for interrogative user interfaces

Liam O'Connor liamoc at cse.unsw.edu.au
Sun Jul 1 10:17:41 CEST 2012

Hi all,

wizards is an Haskell library designed for the quick and painless development of interrogative programs, which revolve around a "dialogue" with the user, who is asked a series of questions in a sequence much like an installation wizard.

Everything from interactive system scripts, to installation wizards, to full-blown shells can be implemented with the support of wizards.

It is developed transparently on top of a free monad (see Swierstra's excellent paper on this topic at http://www.cs.ru.nl/~W.Swierstra/Publications/DataTypesALaCarte.pdf), which separates out the semantics of the program from the wizards interface. A variety of backends exist, including a full featured backend for Haskeline, a debug-friendly simpler implementation in terms of System.IO primitives, and a completely pure implementation modelled as a function from an input string to output. It is also possible to write your own backends, or extend the existing back-ends with new features.

While both built-in IO backends operate on a console, there is no reason why wizards cannot also be used for making GUI wizard interfaces.

The library is highly extensible - back-ends can be written or extended with the type system helpfully tracking what features are supported by which back-ends. 

Installation instructions and some educational examples are at the github page:


Information on how to write backends or extend backends, as well as structured API documentation is available on Hackage:


(Or, you can just run cabal haddock to generate the documentation from the source).

Liam O'Connor

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