Strictification of Circular Programs

摘要

Circular functional programs (necessarily evaluated lazily) have been used as algorithmic tools, as attribute grammar implementations, and as target for program transformation techniques. Classically, Richard Bird [1984] showed how to transform certain multi-traversal programs (which could be evaluated strictly or lazily) into one-traversal ones using circular bindings. Can we go the other way, even for programs that are not in the image of his technique? That is the question we pursue in this paper. We develop an approach that on the one hand lets us deal with typical examples corresponding to attribute grammars, but on the other hand also helps to derive new algorithms for problems not previously in reach.