package preface

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

Source file predicate.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
type 'a t = 'a -> bool

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

  let contramap f g = Preface_core.Fun.(g % f)
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 divide f pa pb x =
        let a, b = f x in
        pa a && pb b
      ;;

      let conquer _ = true
    end)

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

      let choose f pa pb c = Stdlib.Either.fold ~left:pa ~right:pb (f c)
      let lose a x = Void.absurd (a x)
    end)

let negate p x = not (p x)
let tautology _ = true
let contradiction _ = false
let and_ l r x = l x && r x
let or_ l r x = l x || r x

module Infix = struct
  let ( && ) = and_
  let ( || ) = or_
  let ( ! ) = negate
end

include Infix
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