lib/eq.ml

   1 (*pp deriving *)
   2
   3 (* Copyright Jeremy Yallop 2007.
   4    This file is free software, distributed under the MIT license.
   5    See the file COPYING for details.
   6 *)
   7
   8 module type Eq =
   9 sig
  10   type a
  11   val eq : a -> a -> bool
  12 end
  13
  14 module Defaults (E : Eq) = E
  15
  16 module Eq_immutable(S : sig type a end) :
  17   Eq with type a = S.a =
  18 struct
  19   type a = S.a
  20   let eq = (=)
  21 end
  22
  23 module Eq_mutable(S : sig type a end) :
  24   Eq with type a = S.a =
  25 struct
  26   type a = S.a
  27   let eq = (==)
  28 end
  29
  30 module Eq_int = Eq_immutable(struct type a = int end)
  31 module Eq_bool = Eq_immutable(struct type a = bool end)
  32 module Eq_float = Eq_immutable(struct type a = float end)
  33 module Eq_unit = Eq_immutable(struct type a = unit end)
  34 module Eq_char = Eq_immutable(struct type a = char end)
  35
  36 module Eq_string = Eq_mutable(struct type a = string end)
  37 module Eq_ref (E : Eq) = Eq_mutable(struct type a = E.a ref end)
  38 module Eq_array (E : Eq) = Eq_mutable(struct type a = E.a array end)
  39
  40 module Eq_option (E : Eq)
  41   : Eq with type a = E.a option =
  42 struct
  43   type a = E.a option
  44   let eq l r = match l, r with
  45     | None, None -> true
  46     | Some l, Some r -> E.eq l r
  47     | _ -> false
  48 end
  49
  50 module Eq_map_s_t (E : Eq) (M : Map.S)
  51   : Eq with type a = E.a M.t =
  52 struct
  53   type a = E.a M.t
  54   let eq = M.equal (E.eq)
  55 end
  56
  57 module Eq_list (E : Eq) :
  58   Eq with type a = E.a list =
  59 struct
  60   type a = E.a list
  61   let rec eq l r = match l, r with
  62     | [], [] -> true
  63     | (lfst::lrst), (rfst::rrst) when E.eq lfst rfst -> eq lrst rrst
  64     | _ -> false
  65 end
  66
  67 module Eq_num
  68   : Eq with type a = Num.num =
  69 struct
  70   type a = Num.num
  71   let eq = Num.eq_num
  72 end