Pragmatics of Type-Directed Partial Evaluation

Type directed partial evaluation stems from the residualiz ation of arbitrary static values in dynamic contexts given their type Its algorithm coincides with the one for coercing a subtype value into a supertype value which itself coincides with the one of normalization in the calculus Type directed partial evaluation is thus used to specialize compiled closed programs given their type Since Similix let insertion is a cornerstone of partial evaluators for call by value procedural programs with computational e ects It prevents the duplication of residual computations and more generally maintains the order of dynamic side e ects in residual programs This article describes the extension of type directed partial evaluation to insert residual let expressions This extension requires the user to annot ate arrow types with e ect information It is achieved by delimiting and abstracting control comparably to continuation based specialization in direct style It enables type directed partial evaluation of e ectful pro grams e g a de nitional lambda interpreter for an imperative language that are in direct style The residual programs are in A normal form