mitranim

(defmacro return-or [sym expr] {:pre [(symbol? sym)]}
  `(if (reduced? ~sym) (unreduced ~sym) ~expr))

(defn imp-block [[expr & tail-exprs]]
  (match expr

    (('let pattern init) :seq)
    (if-not tail-exprs
      (list init)
      (match (imp-block tail-exprs)

madvas

(defn partial-right
  "Takes a function f and fewer than the normal arguments to f, and
 returns a fn that takes a variable number of additional args. When
 called, the returned function calls f with additional args + args."
  ([f] f)
  ([f arg1]
   (fn [& args] (apply f (concat args [arg1]))))
  ([f arg1 arg2]
   (fn [& args] (apply f (concat args [arg1 arg2]))))
  ([f arg1 arg2 arg3]