mirror of
https://github.com/janet-lang/janet
synced 2024-11-18 06:34:48 +00:00
57 lines
1.2 KiB
Plaintext
57 lines
1.2 KiB
Plaintext
(defn- reverse-array [t]
|
|
(var n (dec (length t)) )
|
|
(var reversed [])
|
|
(while (>= n 0)
|
|
(array-push reversed (get t n))
|
|
(-- n))
|
|
reversed)
|
|
|
|
|
|
(defn- reverse-tuple [t]
|
|
(def max (length t))
|
|
(var n 0)
|
|
(var reversed (tuple))
|
|
(while (< n max )
|
|
(:= reversed (tuple-prepend reversed (get t n)))
|
|
(++ n))
|
|
reversed)
|
|
|
|
|
|
(defn reverse [t]
|
|
(def the-type (type t))
|
|
(cond (= the-type :tuple) (reverse-tuple t)
|
|
(= the-type :array) (reverse-array t)))
|
|
|
|
|
|
(defmacro if-not
|
|
"Sorthand for (if (not ... "
|
|
[condition exp-1 exp-2]
|
|
(tuple 'if (tuple 'not condition)
|
|
exp-1
|
|
exp-2))
|
|
|
|
(defn comp0-
|
|
"Compose two functions. Second function must accept only one argument)"
|
|
[f g] (fn [x] (f (g x))))
|
|
|
|
|
|
(defn comp
|
|
"Takes multiple functions and returns a function that is the composition
|
|
of those functions. Resulting function accepts a variable number of
|
|
arguments"
|
|
[& functions]
|
|
(def len (length functions))
|
|
(if (zero? len)
|
|
nil
|
|
(if (one? len)
|
|
(do
|
|
(def the-composition (get functions 0))
|
|
(fn [& x]
|
|
(apply the-composition x)))
|
|
(do
|
|
(def f (get functions 0))
|
|
(def g (get functions 1))
|
|
(apply comp (comp0 f g) (array-slice functions 2 -1))) )))
|
|
|
|
|