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https://github.com/c-cube/ocaml-containers.git
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109 lines
2.2 KiB
OCaml
109 lines
2.2 KiB
OCaml
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(* This file is free software, part of containers. See file "license" for more details. *)
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type t = int
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let equal (a:int) b = a=b
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let compare (a:int) b = Pervasives.compare a b
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let hash i = i land max_int
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let sign i =
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if i < 0 then -1
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else if i>0 then 1
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else 0
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let neg i = -i
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let pow a b =
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let rec aux acc = function
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| 1 -> acc
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| n ->
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if n mod 2 = 0
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then aux (acc*acc) (n/2)
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else acc * (aux (acc*acc) (n/2))
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in
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match b with
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| 0 -> if a = 0 then raise (Invalid_argument "pow: undefined value 0^0") else 1
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| b when b < 0 -> raise (Invalid_argument "pow: can't raise int to negative power")
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| b -> aux a b
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(*$T
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pow 2 10 = 1024
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pow 2 15 = 32768
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pow 10 5 = 100000
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pow 1 0 = 1
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pow 0 1 = 0
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*)
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type 'a printer = Format.formatter -> 'a -> unit
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type 'a random_gen = Random.State.t -> 'a
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let random n st = Random.State.int st n
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let random_small = random 100
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let random_range i j st = i + random (j-i) st
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let pp fmt = Format.pp_print_int fmt
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let most_significant_bit =
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(-1) lxor ((-1) lsr 1)
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let to_string = string_of_int
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let of_string s =
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try Some (int_of_string s)
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with _ -> None
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type output = char -> unit
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(* abstract printer *)
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let to_binary_gen (out:output) n =
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let n = if n<0 then (out '-'; -n) else n in
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out '0'; out 'b';
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let rec loop started bit n =
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if bit = 0 then (
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if not started then out '0'
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) else (
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let b = n land bit in
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if b = 0 then (
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if started then out '0';
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loop started (bit lsr 1) n
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) else (
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out '1';
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loop true (bit lsr 1) n
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)
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)
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in
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loop false most_significant_bit n
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let pp_binary out n =
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to_binary_gen (Format.pp_print_char out) n
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let to_string_binary n =
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let buf = Buffer.create 16 in
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to_binary_gen (Buffer.add_char buf) n;
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Buffer.contents buf
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(*$= & ~printer:CCFun.id
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"0b111" (to_string_binary 7)
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"-0b111" (to_string_binary (-7))
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"0b0" (to_string_binary 0)
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*)
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(*$Q & ~count:10_000
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Q.int (fun n -> n = int_of_string (to_string_binary n))
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*)
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module Infix = struct
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let (=) = Pervasives.(=)
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let (<>) = Pervasives.(<>)
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let (<) = Pervasives.(<)
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let (>) = Pervasives.(>)
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let (<=) = Pervasives.(<=)
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let (>=) = Pervasives.(>=)
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end
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include Infix
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let min = min
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let max = max
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