jank (experimental)

Part of Dialects and runtimes.

Unlike ClojureDart and JVM Clojure, you start nothing: Jonquil launches a jank repl per window, on the first evaluation.

A window picks jank for a .jank file, or when .jonquil.edn says {:dialect :jank}.
Install jank with brew install jank-lang/jank/jank, or set JONQUIL_JANK to a binary. Lookup order: JONQUIL_JANK, jank on PATH, /opt/homebrew/bin/jank, ~/.local/bin/jank. With none, the first Run says so.
The status bar reads jank (not running), then jank (running).

A jank window after Run: the console starts jank, prints the program's line, then answers a REPL entry in the file's namespace

How it runs

jank runs from a private temporary folder, so your project's .nrepl-port is never touched. The module path is <project>/src (or the project folder). For a loose file it's the root its ns implies, so a sibling namespace loads; if ns doesn't match the path, it's the file's folder. Closing the window removes the folder and stops jank.

Run sends a load-file and moves the prompt to the file's namespace. Run Selection and Run Form use the buffer's namespace, and ask you to Run the file first if it isn't loaded.
Stop kills and restarts jank, since it has no interrupt; earlier definitions are gone.
Reset on Run is on by default: a Run restarts jank first (except for the first request).
For a loose .jank file, start with Run. If a REPL line or Run Selection starts jank first, it lacks the module path and a sibling require fails until a Run restarts it.

Quick documentation reads var metadata, and there are no docs while an evaluation runs ("No docs while jank is running."). Completion merges jank's names with the offline ones.

Limits

Programs can't read input.
Jump to definition works only inside the buffer, and there's no inspector.
You can't attach to a jank you started yourself.
Output appears only when the evaluation ends, and a Stopped evaluation never shows its output. Watch for "Running..." before pressing Stop.
(loop [] (recur)) and a recur after a when fail with codegen/internal-failure. Put every recur in an if branch: (loop [i 0] (if (< i n) (recur (inc i)) i)).