Retrofitting Effect Handlers onto OCaml

Autor: Sivaramakrishnan, KC, Dolan, Stephen, White, Leo, Kelly, Tom, Jaffer, Sadiq, Madhavapeddy, Anil
Rok vydání: 2021
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1145/3453483.3454039
Popis: Effect handlers have been gathering momentum as a mechanism for modular programming with user-defined effects. Effect handlers allow for non-local control flow mechanisms such as generators, async/await, lightweight threads and coroutines to be composably expressed. We present a design and evaluate a full-fledged efficient implementation of effect handlers for OCaml, an industrial-strength multi-paradigm programming language. Our implementation strives to maintain the backwards compatibility and performance profile of existing OCaml code. Retrofitting effect handlers onto OCaml is challenging since OCaml does not currently have any non-local control flow mechanisms other than exceptions. Our implementation of effect handlers for OCaml: (i) imposes a mean 1% overhead on a comprehensive macro benchmark suite that does not use effect handlers; (ii) remains compatible with program analysis tools that inspect the stack; and (iii) is efficient for new code that makes use of effect handlers.
Comment: Accepted to PLDI 2021
Databáze: arXiv