110 lines
2.3 KiB
OCaml
110 lines
2.3 KiB
OCaml
(* List operations *)
|
|
|
|
let rec length = function
|
|
[] -> 0
|
|
| a::l -> 1 + length l
|
|
|
|
let hd = function
|
|
[] -> failwith "hd"
|
|
| a::l -> a
|
|
|
|
let tl = function
|
|
[] -> failwith "tl"
|
|
| a::l -> l
|
|
|
|
let rec nth l n =
|
|
match l with
|
|
[] -> failwith "nth"
|
|
| a::l -> if n <= 0 then a else nth l (n-1)
|
|
|
|
let rec rev_append accu = function
|
|
[] -> accu
|
|
| a::l -> rev_append (a :: accu) l
|
|
|
|
let rev l = rev_append [] l
|
|
|
|
let rec flatten = function
|
|
[] -> []
|
|
| l::r -> l @ flatten r
|
|
|
|
let rec map f = function
|
|
[] -> []
|
|
| a::l -> let r = f a in r :: map f l
|
|
|
|
(* let rec map f = function
|
|
[] -> []
|
|
| a::l -> f a :: map f l *)
|
|
|
|
let rec iter f = function
|
|
[] -> ()
|
|
| a::l -> f a; iter f l
|
|
|
|
|
|
let rec fold_left f accu l =
|
|
match l with
|
|
[] -> accu
|
|
| a::l -> fold_left f (f accu a) l
|
|
|
|
let rec fold_right f l accu =
|
|
match l with
|
|
[] -> accu
|
|
| a::l -> f a (fold_right f l accu)
|
|
|
|
let rec map2 f l1 l2 =
|
|
match (l1, l2) with
|
|
([], []) -> []
|
|
| (a1::l1, a2::l2) -> f a1 a2 :: map2 f l1 l2
|
|
| (_, _) -> invalid_arg "List.map2"
|
|
|
|
let rec iter2 f l1 l2 =
|
|
match (l1, l2) with
|
|
([], []) -> ()
|
|
| (a1::l1, a2::l2) -> f a1 a2; iter2 f l1 l2
|
|
| (_, _) -> invalid_arg "List.iter2"
|
|
|
|
let rec fold_left2 f accu l1 l2 =
|
|
match (l1, l2) with
|
|
([], []) -> accu
|
|
| (a1::l1, a2::l2) -> fold_left2 f (f accu a1 a2) l1 l2
|
|
| (_, _) -> invalid_arg "List.fold_left2"
|
|
|
|
let rec fold_right2 f l1 l2 accu =
|
|
match (l1, l2) with
|
|
([], []) -> accu
|
|
| (a1::l1, a2::l2) -> f a1 a2 (fold_right2 f l1 l2 accu)
|
|
| (_, _) -> invalid_arg "List.fold_right2"
|
|
|
|
let rec for_all p = function
|
|
[] -> true
|
|
| a::l -> p a & for_all p l
|
|
|
|
let rec exists p = function
|
|
[] -> false
|
|
| a::l -> p a or exists p l
|
|
|
|
let rec mem x = function
|
|
[] -> false
|
|
| a::l -> a = x or mem x l
|
|
|
|
let rec assoc x = function
|
|
[] -> raise Not_found
|
|
| (a,b)::l -> if a = x then b else assoc x l
|
|
|
|
let rec mem_assoc x = function
|
|
[] -> false
|
|
| (a,b)::l -> a = x or mem_assoc x l
|
|
|
|
let rec assq x = function
|
|
[] -> raise Not_found
|
|
| (a,b)::l -> if a == x then b else assq x l
|
|
|
|
let rec split = function
|
|
[] -> ([], [])
|
|
| (x,y)::l ->
|
|
let (rx, ry) = split l in (x::rx, y::ry)
|
|
|
|
let rec combine = function
|
|
([], []) -> []
|
|
| (a1::l1, a2::l2) -> (a1, a2) :: combine(l1, l2)
|
|
| (_, _) -> invalid_arg "List.combine"
|