package containers

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Order combinators


type 'a t = 'a -> 'a -> int

Comparison (total ordering) between two elements, that returns an int.

val poly : 'a t

Polymorphic "magic" comparison. Use with care, as it will fail on some types.

  • since 3.6
val compare : 'a t

Polymorphic "magic" comparison.

  • deprecated

    since 3.6 in favor of poly. The reason is that compare is easily shadowed, can shadow other comparators, and is just generally not very descriptive.

val opp : 'a t -> 'a t

Opposite order. For example, opp cmp a b < 0 iff cmp b a > 0. This can be used to sort values in the opposite order, among other things.

val equiv : int -> int -> bool

Returns true iff the two comparison results are the same.

val int : int t
val string : string t
val bool : bool t
val float : float t

Lexicographic Combination

val (<?>) : int -> ('a t * 'a * 'a) -> int

c1 <?> (ord, x, y) returns the same as c1 if c1 is not 0; otherwise it uses ord to compare the two values x and y, of type 'a.

Example: 1 3
<?> (, "a", "b")
<?> (, true, false)

Same example, using only CCOrd::

CCOrd.(int 1 3
  <?> (string, "a", "b")
  <?> (bool, true, false))
val option : 'a t -> 'a option t

Comparison of optional values. None is smaller than any Some _.

  • since 0.15
val pair : 'a t -> 'b t -> ('a * 'b) t
val triple : 'a t -> 'b t -> 'c t -> ('a * 'b * 'c) t
val list : 'a t -> 'a list t

Lexicographic combination on lists.

val array : 'a t -> 'a array t
val map : ('a -> 'b) -> 'b t -> 'a t

map f ord is the comparison function that, given objects x and y, projects x and y using f (e.g. using a record field) and then compares those projections with ord. Example: map fst compares values of type (int * 'a) by their first component.

val (>|=) : 'b t -> ('a -> 'b) -> 'a t

Infix equivalent of map.

module Infix : sig ... end

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