package preface

  1. Overview
  2. Docs
package preface
Legend:
Page
Library
Module
Module type
Parameter
Class
Class type
Source

Source file equivalence.ml

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
type 'a t = 'a -> 'a -> bool

module Contravariant = Preface_make.Contravariant.Via_contramap (struct
  type nonrec 'a t = 'a t

  let contramap f g x y = g (f x) (f y)
end)

module Invariant = Preface_make.Invariant.From_contravariant (Contravariant)

module Divisible =
  Preface_make.Divisible.Over_contravariant
    (Contravariant)
    (struct
      type nonrec 'a t = 'a t

      let conquer _ _ = true

      let divide f g h a b =
        let w, x = f a in
        let y, z = f b in
        g w y && h x z
      ;;
    end)

module Decidable =
  Preface_make.Decidable.Over_divisible
    (Divisible)
    (struct
      type nonrec 'a t = 'a t

      let lose f x = Preface_core.Void.absurd (f x)

      let choose f g h a b =
        Stdlib.Either.fold
          ~left:(fun c ->
            match f b with
            | Stdlib.Either.Left d -> g c d
            | Stdlib.Either.Right _ -> false )
          ~right:(fun c ->
            match f b with
            | Stdlib.Either.Left _ -> false
            | Stdlib.Either.Right d -> h c d )
          (f a)
      ;;
    end)

let negate e x y = not (e x y)
OCaml

Innovation. Community. Security.

GitHub Discord Twitter Peertube RSS
About
Changelog Releases Industrial Users Academic Users Why OCaml
Ecosystem
Packages Community Events OCaml Planet Jobs
Resources
Install OCaml Get Started Platform Tools Language Manual Standard Library API Books Exercises Papers OCaml Playground Logo
Policies
Carbon Footprint Governance Privacy Code of Conduct