kasuboski/pi-extensions/gleam

Gleam: Compiler-First

Use the compiler and installed source as ground truth. Do not write Gleam from Elixir, Erlang, ML, or remembered package APIs.

Project initialization

When creating a Gleam project or adding its development tooling, read `references/project-init.md` and follow its bootstrap and validation steps. It provides reusable mise.toml and shell.nix templates, including a Glinter-backed precommit gate.

Tight loop

1. Identify the affected Gleam package and its repository-prescribed check and

format commands.

1. Before using an uncertain external API, inspect the version installed for

that package. From the package root, run this skill's scripts/gleam-sig <module> [name ...]; if dependencies are absent, download them using the repository-prescribed command first.

1. Make one coherent edit pass, then run the affected package's check command.
2. Read every diagnostic, fix them together, and repeat until the check passes.
3. Run the repository-prescribed formatter or format check. If it changes code,

run the check again.

Work is complete only when the prescribed check and formatting commands pass for every affected Gleam package and every reported diagnostic is addressed. Follow any stronger repository completion requirements as well.

Core traps

When a diagnostic involves one of these rules, read `references/compile-traps.md` for valid examples and caveats before editing.

When choosing between Result and Option, or flattening nested control flow, read `references/control-flow.md` before editing.

Installed API lookup

Run the helper from the affected package root so it reads that package's locked dependencies:

/path/to/this/skill/scripts/gleam-sig gleam/list first
/path/to/this/skill/scripts/gleam-sig gleam/dynamic/decode field
/path/to/this/skill/scripts/gleam-sig sqlight

The helper deliberately has no global fallback: an arbitrary package elsewhere on disk is not ground truth for the affected package. It prints the source path and complete multiline function declaration. Read the source around that location when signatures alone do not establish behaviour.

For CLI syntax, run gleam help or gleam help <command> using the repository's configured Gleam version rather than relying on a maintained command list.