Browser compatibility

Compile Gargamelle for Gleam’s JavaScript target to use it in a browser. The JavaScript target does not require the native Erlang C helper.

The following desktop browsers were tested on macOS arm64 with Gleam 1.18.1:

Each browser passed 45 typed Gleam tests, 17,788 generated input cases across 886 definitions, 594 regex probes and 19 HTML renderer checks. The renderer checks cover disclosure controls, reference navigation, escaping, print-event behavior and row alignment. These checks are bounded evidence, not exhaustive browser compatibility or a performance guarantee. Older releases, mobile browsers, workers, Bun and Deno remain unverified.

Regex Unicode properties

JavaScript regex matching uses the host’s Unicode tables. Native Erlang regex uses Unicode 16 tables, with Node 24.10.0 as the tested parity reference.

The tested browsers accept U+11DB0 as \p{L} and \p{Assigned}, while the Node Unicode 16 reference does not. All probes agree with each browser’s own RegExp; cross-target parity on characters introduced in newer Unicode versions is not claimed. A definition that depends on these Unicode properties may therefore accept different strings on different hosts.

For the core input domain and other limits, see the technical contract. For Erlang installation and deployment, see Native Erlang setup.