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include Stdlib.Array
open Module_types
let is_empty (arr: 'a array): bool =
length arr = 0
let first (arr: 'a array): 'a =
assert (not (is_empty arr));
get arr 0
let last (arr: 'a array): 'a =
let len = length arr in
assert (0 < len);
get arr (len - 1)
let find (p: 'a -> bool) (arr: 'a array): int =
let len = length arr
in
let rec find i =
if i = len || p (get arr i) then
len
else
find (i + 1)
in
find 0
let take (n:int) (arr:'a array): 'a array =
assert (n <= length arr);
sub arr 0 n
let remove_last (n: int) (arr: 'a array): 'a array =
let len = length arr in
assert (n <= len);
take (len - n) arr
let put (i:int) (a:'a) (arr:'a array): 'a array =
assert (i < length arr);
let res = copy arr in
set res i a;
res
let push (a:'a) (arr:'a array): 'a array =
let len = length arr in
init
(len + 1)
(fun i ->
if i < len then
get arr i
else
a)
let fill (n: int) (e: 'a) (arr: 'a array): 'a array =
let len = length arr in
let arr_new = make (len + n) e in
blit arr 0 arr_new 0 len;
arr_new
let foldi_left (f: 'a -> int -> 'b -> 'a) (a: 'a) (arr: 'b array): 'a =
let len = length arr
in
let rec fold a i =
if i = len then
a
else
fold (f a i (get arr i)) (i + 1)
in
fold a 0
let foldi_right (f: int -> 'a -> 'b -> 'b) (arr: 'a array) (b: 'b): 'b =
let len = length arr
in
let rec fold i b =
if i = 0 then
b
else
let i = i - 1 in
fold i (f i (get arr i) b)
in
fold len b
module Monadic (M: MONAD) =
struct
let mapi
(f: int -> 'a -> 'b M.t)
(arr: 'a array)
: 'b array M.t
=
let len = length arr in
if 0 < len then
let open M in
f 0 (get arr 0)
>>= fun b ->
let arr2 = make len b in
let rec make_from i =
if i = len then
return arr2
else
(
f i (get arr i) >>= fun b ->
set arr2 i b;
make_from (i + 1)
)
in
make_from 1
else
M.return [||]
let map
(f: 'a -> 'b M.t)
(arr: 'a array)
: 'b array M.t
=
mapi (fun _ -> f) arr
let foldi_left
(f: int -> 'a -> 'b -> 'b M.t)
(arr: 'a array)
(b: 'b)
: 'b M.t
=
let len = length arr
in
let rec fold_from i b =
if i = len then
M.return b
else
M.(f i (get arr i) b >>= fold_from (i + 1))
in
fold_from 0 b
let fold_left
(f: 'a -> 'b -> 'b M.t)
(arr: 'a array)
(b: 'b)
: 'b M.t
=
foldi_left
(fun _ -> f)
arr
b
end