Awsum

A functional language with strong static typing, focused on reliability.

Key features

• Friendly CLI (typecheck, build, run, format)
• The behavior is tested to be equivalent across targets.

Targets

• JS
• Lua

Editor support

VSCode

• Install the Awsum extension to enable syntax highlight and code formatting
• Enable format on save

{
  // settings.json
  "[awsum]": {
    "editor.formatOnSave": true,
    "editor.defaultFormatter": "awsum-lang.awsum-vscode"
  }
}

Other editors

• EBNF grammar
• TextMate grammar

Examples

• hello.aww
• polymorphism.aww

Installation

• Install Stack via ghcup
• Install Node.js via NVM (for targeting JS)
• Install Lua via brew install lua (for targeting Lua)
• stack build
• stack install
• Make sure ~/.local/bin is in PATH

Usage

• awsum build FILE [-t js] [-o OUT] — compile to target and write to file (or stdout).
• awsum run FILE [-t js] [--input TEXT | --stdin] — compile to a temp file and execute with the system runtime, passing input to main.
• awsum check FILE — parse and typecheck; prints OK or a descriptive error.
• awsum format FILE [-i|--in-place] — render . parse with stable formatting. Preserves comments (including trailing inline), keeps a blank line between top-level blocks, and ends the file with a trailing newline.
• awsum ast FILE — pretty-print the surface AST (for debugging).
• awsum core FILE — print elaborated/lowered Core (post type elaboration) (for debugging).
• awsum --version — show version

Examples:

awsum build test/sources/hello.aww -t js  -o out.js  && node out.js "world"
awsum build test/sources/hello.aww -t lua -o out.lua && lua out.lua "world"

awsum run test/sources/hello.aww -t js  --input "world"
awsum run test/sources/hello.aww -t lua --input "world"

echo "world" | awsum run test/sources/hello.aww -t js  --stdin
echo "world" | awsum run test/sources/hello.aww -t lua --stdin

awsum check  test/sources/hello.aww
awsum format test/sources/hello.aww -i
awsum ast    test/sources/hello.aww
awsum core   test/sources/hello.aww
awsum --version

Roadmap

• Equivalent behavior for numbers and strings across different runtimes.
• All arithmetic operations via Either. No silent underflow, overflow, precision loss. No NaN, Infinity, -0, etc.
• A compiler aware of dependency between application formats (cli, browser), targets (JS, Lua) and specific effects (Terminal, DOM, Ports) to allow compilation only for a specific set of effects.

Notes

• The syntax and semantics is inspired by Elm.
• The name is inspired by the AWSUM keyword of the LOLCODE language.