poly-con.md

Polymorphic contracts

(ns utyped1)

(defn id identity)

(ns ^:core.typed typed
  (:require [clojure.core.typed :as t]
            [^{:require-typed
               {id (t/All [x] [x -> x])}}
             utyped1 :as u]))

(t/ann fidentity
  (All [[x :< [Int -> Int]]] [x -> x]))
(def fidentity identity)
;  (fn [X]
;    (fn [a :- X]
;      ((inst identity X) a))))

(deftype [X] Cons [fst rst]
  PCons
  (first [this] ((inst u/id X) fst))

(ns untyped
  (:require [typed :as tt]))

;; t/fidentity considered [[Int -> Int] -> Any]
(t/fidentity (cast (fn [a] a) [Int -> Int]))