Safe Haskell	None
Language	Haskell2010

Data.Fin.Enum

Contents

Description

This module is designed to be imported qualified:

import qualified Data.Fin.Enum as E

Synopsis

Documentation

class Enum a where #

Generic enumerations.

Examples:

>>> from ()
0

>>> to 0 :: ()
()

>>> to 0 :: Bool
False

>>> map to F.universe :: [Bool]
[False,True]

>>> map (to . (+1) . from) [LT, EQ, GT] :: [Ordering] -- Num Fin is modulo arithmetic
[EQ,GT,LT]

Associated Types

The size of an enumeration.

Methods

Converts a value to its index.

Converts a value to its index.

to :: Fin (EnumSize a) -> a #

Converts from index to the original value.

Converts from index to the original value.

Instances

Enum Bool #	`Bool` ~ 2
Instance details Defined in Data.Fin.Enum Associated Types type EnumSize Bool :: Nat # Methods from :: Bool -> Fin (EnumSize Bool) # to :: Fin (EnumSize Bool) -> Bool #
Enum Ordering #	`Ordering` ~ 3
Instance details Defined in Data.Fin.Enum Associated Types type EnumSize Ordering :: Nat # Methods from :: Ordering -> Fin (EnumSize Ordering) # to :: Fin (EnumSize Ordering) -> Ordering #
Enum () #	() ~ 1
Instance details Defined in Data.Fin.Enum Associated Types type EnumSize () :: Nat # Methods from :: () -> Fin (EnumSize ()) # to :: Fin (EnumSize ()) -> () #
Enum Void #	`Void` ~ 0
Instance details Defined in Data.Fin.Enum Associated Types type EnumSize Void :: Nat # Methods from :: Void -> Fin (EnumSize Void) # to :: Fin (EnumSize Void) -> Void #

Generic implementation

Generic version of from.

type GFrom a = GFromRep (Rep a) #

Constraint for the class that computes gfrom.

gto :: (Generic a, GTo a) => Fin (GEnumSize a) -> a #

Generic version of to.

type GTo a = GToRep (Rep a) #

Constraint for the class that computes gto.

type GEnumSize a = EnumSizeRep (Rep a) Nat0 #

Compute the size from the type.