6 Module System Issues

In my disseratation I speculate on the possible translation of Haskell's module system features to Clean's. However, in practice, there are a few obstacles which are particularly difficult to overcome:

• In Haskell a function can be defined and exported to another module without ever having to specify its type signature. For a function to be exported in Clean, its type-signature must be stated in a definition file for the module.

• Haskell module system behaviours such as closure, qualified names, instance imports/exports are not easy to translate (closure would require a type-checker to resolve). I'm sure there are other good reasons, but I have to admit to forgetting them. Sorry!

In our tool Hacle, we translate a Haskell program consisting of potentially many modules, to a Clean program of just one module. This translation is based on the following principle:

``A multi-module Haskell program can be converted into a single-module program by giving each entity a unique name, changing all occurrences to refer to the appropriate unique name, and then concatenating all the module bodies.'' - Haskell'98 Report.