schema_helpers.clj

(ns schema-helpers
  (:require [schema.core :as s]))

(defn tuple
  "Returns a schema for a sequence containing exactly the schema/name pairs.
   To denote an optional element use {schema name} instead of [schema name].

   Example:
   (def t (tuple [String 'foo] [s/Keyword 'bar] {Number 'num}))

   (s/check t [\"blah\" :boo])
   ==> nil

   (s/check t [\"blah\" :boo 23])
   ==> nil

   (s/check t [\"blah\" \"not keyword\"])
   ==> [nil (named (not (keyword? \"not keyword\")) bar)] "
  [& schema-name-pairs]
  (->> schema-name-pairs
       (mapv (fn [pair]
               (if (map? pair)
                 (apply s/optional (-> pair seq first))
                 (apply s/one pair))))))