Experiment: (vibe "...") — LLM code generation spliced in place

[nooga]

Draft / experiment — not for mainline as-is.

Type a call where you want the code, put point in it, press C-c C-v:

(defn triple [x] (* 3 x))

(vibe "a fn that doubles x, named double")

(defn triple [x] (* 3 x))

(defn double [x]
  (* 2 x))

One undo puts the call back.

What makes the answers usable

The model gets the whole buffer with the call site swapped for a
<<<VIBE:HERE>>> marker, plus the column that marker starts at — so it writes
code shaped to fit that spot (surrounding defns, aliases, indentation) rather
than a generic answer to the prompt in isolation.

vibe stays an ordinary function: C-x C-e on the form echoes the generated
code instead of splicing it, and (str (vibe "a") (vibe "b")) works.
vibe-replace parks the call site in an atom for the duration of the eval
rather than passing it as an argument, which is what makes both true at once.

Blocking without freezing

This is the only command in legmacs that waits on something slow, and it stays
out of the pure pipeline. vibe-replace does no I/O — it sets
:message "vibing..." plus :pending-vibe and returns, exactly like any other
command. main.lg's loop paints that frame, then resolve-effects runs the
request. Inline I/O would have left the screen frozen on a stale frame for the
whole round trip with no way to say what it was waiting for.

Setup

~/.config/legmacs/vibe.edn:

{:key "sk-..."}

Optional :model (default gpt-5.6-luna). The file is merged wholesale, so
:provider / :url / :max-tokens / :system work from there too. Four
layers, each beating the previous: defaults, vibe.edn, the config atom
(legmacs-init.lg), per-call opts. :openai and :anthropic ship; a provider
is four keys and two functions.

Testing

40 tests, no network: call-site search, prompt building, fence stripping,
config parsing and splicing are pure, and resolve-pending is exercised on the
paths that fail before any HTTP. Verified end to end against a mock OpenAI
server driving the real chord pipeline. Full suite 1029/1029 on let-go 1.12.2.

The first commit is independent and probably should land

1aade41 fixes a pre-existing bug that has nothing to do with vibe:
load-stringing a buffer that opens with (ns foo) — every real .lg file —
relocates the running namespace permanently, even from inside a compiled
function. Since legmacs evaluates in its own live namespace, one C-c C-e on
an ordinary file cost you buf/, km/, dispatch/ and render/ for the rest
of the session, and the next C-x C-e failed with "Can't resolve ... in this
context". vibe just made it visible. Cherry-pick it out if this branch never
merges.

🤖 Generated with Claude Code