letfn is a macro over a letfn* special form (Clojure semantics)

jolt modelled letfn as a special form directly, so (macroexpand-1 '(letfn …))
returned the form unchanged. Clojure's letfn is a macro that expands to letfn*,
and macroexpansion tooling (tools.macro, tools.analyzer) depends on that — its
special-form handlers key on letfn*, not letfn.

Split it the Clojure way:
- letfn* is now the special form (analyzer), taking flat name/fn-form pairs
  [name1 fn1 name2 fn2 …] — the letrec :let lowering is unchanged.
- letfn is a macro (00-syntax) turning each (name [params] body*) spec into a
  name + (fn name [params] body*) binding, so it expands to letfn*.

So (macroexpand-1 '(letfn [(f [x] x)] (f 1))) now yields
(letfn* [f (fn f [x] x)] (f 1)), and clojure.tools.macro passes its whole suite
(macrolet / symbol-macrolet / mexpand-all). Listed in docs + site.

make test green (+1 corpus row, 0 new divergences), shakesmoke byte-identical.
One re-mint (analyzer + the letfn macro); selfhost holds.
This commit is contained in:
Yogthos 2026-06-27 17:26:18 -04:00
parent 7891fa0d55
commit 21cd88deee
6 changed files with 341 additions and 330 deletions

View file

@ -159,6 +159,15 @@
(defmacro declare [& syms]
`(do ~@(map (fn* [s] `(def ~s)) syms)))
;; letfn is a macro over the letfn* special form, matching Clojure: each
;; (name [params] body*) spec becomes a name + a (fn name [params] body*) binding.
;; So (macroexpand-1 '(letfn …)) yields the letfn* form macroexpansion tooling
;; (tools.macro / tools.analyzer) expects, instead of an opaque special form.
(defmacro letfn [fnspecs & body]
(cons 'letfn*
(cons (reduce (fn [acc s] (conj (conj acc (first s)) (cons 'fn s))) [] fnspecs)
body)))
;; destructure — Clojure's binding-vector expander.
;; Turns a binding vector that may contain destructuring
;; patterns into a plain binding vector (alternating symbol / init-form) built from