A type-preserving closure conversion in haskell

Abstract

The use of typed intermediate languages can significantly increase the reliability of a compiler. By type-checking the code produced at each transformation stage, one can identify bugs in the compiler that would otherwise be much harder to find. Also it guarantees that any property that was enforced by the source-level type-system is holds also or the generated code. Recently, several people have tried to push this effort a bit further by verifying formally that the compiler indeed preserves typing. This is usually done with proof assistants or experimental languages.