Lash

Lash is a Lua-like scripting language that lowers directly to Bash.

This repository contains:

• lash: CLI entrypoint
• lashc: compiler (.lash -> .sh)
• lashfmt: formatter
• lash-lsp: language server

Status

Lash is under active development. The current implemented surface is documented in:

• docs/web/site/index.html (interactive HTML docs)
• docs/book/README.md (markdown source for the user guide)
• docs/language-spec.md (reference)

Implemented language features include:

• mutable, immutable, readonly, and global declarations
• arrays and string-keyed map literals
• functions, enums, switch, and Bash-oriented control flow
• for, select, while, until, break N, and continue N
• raw shell command statements, $(...), process substitution, redirections, traps, background jobs, and coproc

Requirements

• .NET SDK (net10.0)
• Bash

Quick Start

Build interactive HTML docs:

just docs-web-build

Open the web docs:

xdg-open docs/web/site/index.html

Read the markdown book source:

cat docs/book/README.md

Preview interactive docs locally:

just docs-web-preview

Run a Lash script:

lash run script.lash arg1 arg2

Check a script without emitting Bash:

lash check script.lash

Compile a script to Bash:

lash compile script.lash -o script.sh
bash script.sh

Format Lash files:

lash format .
lash format . --check

Watch Lash files and recompile on changes:

lash watch script.lash
lash watch src/

CLI Commands

From lash --help:

• compile <file>: compile .lash to Bash (-o/--output optional)
• check <file>: validate a .lash file without emission
• format <paths>...: format files/directories (--check supported)
• run <file> [args...]: compile to temp Bash and execute
• watch <paths>...: watch .lash files/directories and recompile changed files

Use --verbose on commands for extra phase and progress logs.