# Copyright (c) 2017 Calvin Rose
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

# Bootstrap the language 

(def defmacro macro (fn [name & more]
  (tuple 'def name 'macro (tuple-prepend (tuple-prepend more name) 'fn))))
(defmacro defn 
  [name & more]
  (tuple 'def name 
   (tuple-prepend (tuple-prepend more name) 'fn)))

(defmacro when [cond & body] (tuple 'if cond (tuple-prepend body 'do)))

(defn array-seq [x]
  (def len (length x))
  (var i 0)
  {
    :more (fn [] (< i len))
    :next (fn []
      (def ret (get x i))
      (varset! i (+ i 1))
      ret) 
  })

(def seqs {
  :array array-seq
  :tuple array-seq
  :struct (fn [x] x)})

(defn seq [x]
 (def makeseq (get seqs (type x)))
 (if makeseq (makeseq x) (error "expected sequence")))

(defn range [top]
  (var i 0)
  {
    :more (fn [] (< i top))
    :next (fn []
      (def ret i)
      (varset! i (+ i 1))
      i) 
  })

(defn doseq [s f] 
 (def s (seq s))
 (def more? (get s :more))
 (def getnext (get s :next))
 (while (more?)
    (f (getnext))))

(defn map [f s]
 (def s (seq s))
 (def more (get s :more))
 (def getnext (get s :next))
 {
  :more more
  :next (f (getnext))
 })