Interactive Elixir AST explorer

Type some Elixir(ish) code, have it parsed by the Elixir parser, and inspect the output in real time. Like Code.string_to_quoted/2, but in a browser.

Live: https://ast.miraclethings.nl/

Built with Phoenix LiveView. Besides the AST, it shows the tokenizer output, AST → string round-tripping, the AST as JSON, the formatter's algebra document, a filter-expression-to-SQL demo and a small leex/yecc integer parser.

Running locally

Needs Elixir 1.19 / OTP 28 (see .tool-versions); no Node.js.

mix setup
mix phx.server

Then open http://localhost:4000.

Docker

Every push to master is tested and published to ghcr.io/arjan/ast_ninja:latest.

docker run -p 4000:4000 \
  -e SECRET_KEY_BASE=$(mix phx.gen.secret) \
  -e PHX_HOST=localhost \
  ghcr.io/arjan/ast_ninja:latest

Variable	Required	Default
SECRET_KEY_BASE	yes
PHX_HOST	no	ast.ninja
PORT	no	4000

PHX_HOST is also used to check the websocket origin, so set it to the hostname the site is served on.