Phil Eaton • 6/27/2026

The feature in OxCaml that more languages should steal

This article discusses OxCaml, Jane Street's superset of OCaml, and its [@zero_alloc] assertion that lets developers mark functions as non-allocating on the heap, with the compiler failing if allocation occurs. It contrasts this with the typical approach in languages like Java, Go, C#, Rust, and Zig, where profilers are used to find allocations. The article includes a tutorial on installing OxCaml and writing a naive CSV summing program to demonstrate the feature, highlighting how compiler-enforced zero allocation can prevent performance regressions.

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#static analysis #Ocaml #Oxcaml