core.mal

   1 (def! dec (fn* (a) (- a 1)))
   2
   3 (def! zero? (fn* (n) (= 0 n)))
   4
   5 (def! reduce
   6   (fn* (f init xs)
   7     (if (empty? xs)
   8       init
   9       (reduce f (f init (first xs)) (rest xs)))))
  10
  11 (def! identity (fn* (x) x))
  12
  13 (def! every?
  14   (fn* (pred xs)
  15     (if (empty? xs)
  16       true
  17       (if (pred (first xs))
  18         (every? pred (rest xs))
  19         false))))
  20
  21 (def! some
  22   (fn* (pred xs)
  23     (if (empty? xs)
  24       nil
  25       (let* (res (pred (first xs)))
  26         (if res
  27           res
  28           (some pred (rest xs)))))))
  29
  30 (defmacro! and
  31   (fn* (& xs)
  32     (if (empty? xs)
  33       true
  34       (if (= 1 (count xs))
  35         (first xs)
  36         (let* (condvar (gensym))
  37           `(let* (~condvar ~(first xs))
  38             (if ~condvar (and ~@(rest xs)) ~condvar)))))))
  39
  40 (defmacro! ->
  41   (fn* (x & xs)
  42     (if (empty? xs)
  43       x
  44       (let* (form (first xs)
  45              more (rest xs))
  46         (if (empty? more)
  47           (if (list? form)
  48             `(~(first form) ~x ~@(rest form))
  49             (list form x))
  50           `(-> (-> ~x ~form) ~@more))))))
  51
  52 (defmacro! ->>
  53   (fn* (x & xs)
  54     (if (empty? xs)
  55       x
  56       (let* (form (first xs)
  57              more (rest xs))
  58         (if (empty? more)
  59           (if (list? form)
  60             `(~(first form) ~@(rest form) ~x)
  61             (list form x))
  62           `(->> (->> ~x ~form) ~@more))))))
  63
  64 ; This `nil` is intentional so that the result of doing `load-file` is
  65 ; `nil` instead of whatever happens to be at the end of `core.mal`.
  66 nil