spec.cljs

(ns kilppari.spec
  (:require [clojure.spec.alpha :as s]))

(s/def ::v (s/or :variable keyword?
                 :value number?))

(s/def ::command keyword?)

(defmulti by-command (fn [[command _]] command))
(defmethod by-command :move [_]
  (s/tuple ::command ::v))
(defmethod by-command :turn [_]
  (s/tuple ::command ::v))
(defmethod by-command :repeat [_]
  (s/tuple ::command ::v ::script))
(defmethod by-command :pen [_]
  (s/tuple ::command #(or (= % :up) (= % :down))))
(defmethod by-command :let [_]
  (s/tuple ::command keyword? number?))
(defmethod by-command :function [_]
  (s/tuple ::command keyword? (s/coll-of keyword?) ::script))
(defmethod by-command :call [_]
  (s/tuple ::command keyword? number?))

(s/def ::instruction (s/multi-spec by-command :instruction))

(s/def ::start (s/tuple #(= :start %) number? number? number?))

;; a (sub)script is a vector of instructions
(s/def ::script (s/coll-of ::instruction))

;; main scripts must have a "start instruction" at the beginning
(s/def ::main-script (fn [[start & rest]]
                       (s/and (s/valid? ::start start)
                              (s/valid? ::script rest))))

(def test-sc [[:start 1 2 3] [:call :circle "invalid"]])
(s/valid? ::script (rest test-sc)) ;; => false as expected
(s/valid? ::main-script test-sc) ;; => true !!! should be false?