A document-centered environment for haskell

This paper describes a document-centered environment for Haskell that is aimed at making the language accessible to a broad range of end users. In this environment (named Vital), Haskell modules are presented as documents with the values they define displayed in place textually or graphically (as ‘views'). An end user, who may have only a superficial knowledge of Haskell, is able to edit a program (for example, manipulating literal values of complex, user-defined ADTs) by interacting with these views. The representation of an ADT and the range of interactions possible with it (that is, its ‘look and feel') are open-ended and are defined (by an expert user) in terms of Haskell type classes and implemented by a mechanism that employs a specialised form of reflection.