An Experiment with the Fourth Futamura Projection

Abstract

We have experimentally validated the theoretical insight, that a compiler generator is an Ershov generating extension of a program specializer, by showing that an existing offline partial evaluator can perform the fourth Futamura projection. Specifically, an online and an offline partial evaluator for an imperative flowchart language were transformed into two new compiler generators by Romanenko's classical partial evaluator Unmix. The two partial evaluators are described, as is a novel recursive method for polyvariant specialization. The new compiler generators are demonstrated by converting a universal parser into a parser generator. These results strongly indicate that existing partial evaluation techniques can be put to work on several new applications. To date, all previous compiler generators based on partial evaluation were either generated by self-application or handwritten. None of these works considered the generation of one compiler generator by another.