Copyright	© Frank Jung 2023
License	GPL-3.0-only
Safe Haskell	Safe-Inferred
Language	Haskell2010

Months

Contents

Types
Type classes
Functions

Description

From Haskell Cookbook by Yogesh Sajanikar, Chapter 3, Working with Type Classes, page 95.

Synopsis

data Month
- = January
- | February
- | March
- | April
- | May
- | June
- | July
- | August
- | September
- | October
- | November
- | December
class (Eq a, Enum a, Bounded a) => CyclicEnum a where
- cpred :: a -> a
- csucc :: a -> a
makeMonth :: String -> Maybe Month

Types

data Month Source #

Months of the year.

Constructors

January
February
March
April
May
June
July
August
September
October
November
December

Instances

Instances details

CyclicEnum Month Source #
Instance details Defined in Months Methods cpred :: Month -> Month Source # csucc :: Month -> Month Source #
Arbitrary Month Source #	Arbitrary instance for `Month`.
Instance details Defined in Months Methods arbitrary :: Gen Month Source # shrink :: Month -> [Month] Source #
Bounded Month Source #
Instance details Defined in Months Methods minBound :: Month # maxBound :: Month #
Enum Month Source #
Instance details Defined in Months Methods succ :: Month -> Month # pred :: Month -> Month # toEnum :: Int -> Month # fromEnum :: Month -> Int # enumFrom :: Month -> [Month] # enumFromThen :: Month -> Month -> [Month] # enumFromTo :: Month -> Month -> [Month] # enumFromThenTo :: Month -> Month -> Month -> [Month] #
Read Month Source #
Instance details Defined in Months Methods readsPrec :: Int -> ReadS Month # readList :: ReadS [Month] # readPrec :: ReadPrec Month # readListPrec :: ReadPrec [Month] #
Show Month Source #
Instance details Defined in Months Methods showsPrec :: Int -> Month -> ShowS # show :: Month -> String # showList :: [Month] -> ShowS #
Eq Month Source #
Instance details Defined in Months Methods (==) :: Month -> Month -> Bool # (/=) :: Month -> Month -> Bool #
Ord Month Source #
Instance details Defined in Months Methods compare :: Month -> Month -> Ordering # (<) :: Month -> Month -> Bool # (<=) :: Month -> Month -> Bool # (>) :: Month -> Month -> Bool # (>=) :: Month -> Month -> Bool # max :: Month -> Month -> Month # min :: Month -> Month -> Month #

Type classes

class (Eq a, Enum a, Bounded a) => CyclicEnum a where Source #

Cyclic bounded enumeration of compass directions.

Minimal complete definition

Nothing

Methods

cpred :: a -> a Source #

Predecessor of a Cyclic enumeration.

csucc :: a -> a Source #

Successor of a Cyclic enumeration.

Instances

Instances details

CyclicEnum Month Source #
Instance details Defined in Months Methods cpred :: Month -> Month Source # csucc :: Month -> Month Source #

Functions

makeMonth :: String -> Maybe Month Source #

Make a Month from a string.