Flambda2 Ep. 2: Loopifying Tail-Recursive Functions

Flambda2's Episode 2 delves into the optimization algorithm Loopify, focusing on tail-recursive functions in OCaml. Loopify aims to reduce memory allocations by transforming recursive and tail-recursive functions into loops. The article discusses the importance of Tail-Call Optimization (TCO) in functional languages like OCaml, ensuring efficient stack memory usage. OCaml guarantees TCO, supporting tail-calls optimization. Loopify addresses the dilemma of reducing allocations versus writing clean code, offering a solution to improve performance without sacrificing functional programming principles. The decision to loopify a function is automatic for purely tail-recursive functions or can be triggered by the user using the [@loop] attribute. The transformation process involves introducing recursive continuations and replacing tail-recursive calls with continuations. Loopify enables Flambda2 to optimize code for performance while maintaining functional programming aesthetics.