Distribution.Simple.Flag

Defines the Flag type and it's Monoid instance, see http://www.haskell.org/pipermail/cabal-devel/2007-December/001509.html for an explanation.

Split off from Distribution.Simple.Setup to break import cycles.

Documentation

data Flag a

All flags are monoids, they come in two flavours:

1. list flags eg

--ghc-option=foo --ghc-option=bar

gives us all the values ["foo", "bar"]

1. singular value flags, eg:

--enable-foo --disable-foo

gives us Just False So this Flag type is for the latter singular kind of flag. Its monoid instance gives us the behaviour where it starts out as NoFlag and later flags override earlier ones.

Constructors

Flag a

NoFlag

Instances

Functor Flag

Defined in Distribution.Simple.Flag

Methods

fmap :: (a -> b) -> Flag a -> Flag b

(<$) :: a -> Flag b -> Flag a

Applicative Flag

Defined in Distribution.Simple.Flag

Methods

pure :: a -> Flag a

(<*>) :: Flag (a -> b) -> Flag a -> Flag b

liftA2 :: (a -> b -> c) -> Flag a -> Flag b -> Flag c

(*>) :: Flag a -> Flag b -> Flag b

(<*) :: Flag a -> Flag b -> Flag a

Bounded a => Bounded (Flag a)

Defined in Distribution.Simple.Flag

Methods

minBound :: Flag a

maxBound :: Flag a

Enum a => Enum (Flag a)

Defined in Distribution.Simple.Flag

Methods

succ :: Flag a -> Flag a

pred :: Flag a -> Flag a

toEnum :: Int -> Flag a

fromEnum :: Flag a -> Int

enumFrom :: Flag a -> [Flag a]

enumFromThen :: Flag a -> Flag a -> [Flag a]

enumFromTo :: Flag a -> Flag a -> [Flag a]

enumFromThenTo :: Flag a -> Flag a -> Flag a -> [Flag a]

Eq a => Eq (Flag a)

Defined in Distribution.Simple.Flag

Methods

(==) :: Flag a -> Flag a -> Bool

(/=) :: Flag a -> Flag a -> Bool

Read a => Read (Flag a)

Defined in Distribution.Simple.Flag

Methods

readsPrec :: Int -> ReadS (Flag a)

readList :: ReadS [Flag a]

readPrec :: ReadPrec (Flag a)

readListPrec :: ReadPrec [Flag a]

Show a => Show (Flag a)

Defined in Distribution.Simple.Flag

Methods

showsPrec :: Int -> Flag a -> ShowS

show :: Flag a -> String

showList :: [Flag a] -> ShowS

Generic (Flag a)

Defined in Distribution.Simple.Flag

Associated Types

type Rep (Flag a) :: * -> *

Methods

from :: Flag a -> Rep (Flag a) x

to :: Rep (Flag a) x -> Flag a

Semigroup (Flag a)

Defined in Distribution.Simple.Flag

Methods

(<>) :: Flag a -> Flag a -> Flag a

sconcat :: NonEmpty (Flag a) -> Flag a

stimes :: Integral b => b -> Flag a -> Flag a

Monoid (Flag a)

Defined in Distribution.Simple.Flag

Methods

mempty :: Flag a

mappend :: Flag a -> Flag a -> Flag a

mconcat :: [Flag a] -> Flag a

Binary a => Binary (Flag a)

Defined in Distribution.Simple.Flag

Methods

put :: Flag a -> Put

get :: Get (Flag a)

putList :: [Flag a] -> Put

type Rep (Flag a)

Defined in Distribution.Simple.Flag

type Rep (Flag a) = D1 (MetaData "Flag" "Distribution.Simple.Flag" "Cabal-2.4.0.1-6VMdF6KlH8vJ0qvAHqwzor" False) (C1 (MetaCons "Flag" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 a)) :+: C1 (MetaCons "NoFlag" PrefixI False) (U1 :: * -> *))

allFlags :: [Flag Bool] -> Flag Bool

toFlag :: a -> Flag a

fromFlag :: WithCallStack (Flag a -> a)

fromFlagOrDefault :: a -> Flag a -> a

flagToMaybe :: Flag a -> Maybe a

flagToList :: Flag a -> [a]

maybeToFlag :: Maybe a -> Flag a

class BooleanFlag a where

Types that represent boolean flags.

Minimal complete definition

asBool

Methods

asBool :: a -> Bool

Instances

BooleanFlag Bool

Defined in Distribution.Simple.Flag

Methods

asBool :: Bool -> Bool