Options.Harg.Types

Documentation

data Opt a

The basic option type

Constructors

Opt

Fields

• _optLong :: Maybe String

  Modifier for long options (e.g. --user)

• _optShort :: Maybe Char

  Modifier for short options (e.g. -u)

• _optHelp :: Maybe String

  Option help to be shown when invoked with --help/-h or in case of error

• _optMetavar :: Maybe String

  Metavar to be shown in the help description

• _optEnvVar :: Maybe String

  Environment variable for use with EnvSource

• _optDefaultVal :: Maybe a

  Default value

• _optDefaultStr :: Maybe String

  Default value as string (unparsed)

• _optReader :: OptReader a

  Option parser

• _optType :: OptType a

  Option type

Instances

Functor Opt

Defined in Options.Harg.Types

Methods

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

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

data OptionOpt (attr :: [OptAttr]) a

Option for flags with arguments. Corresponds to option.

Constructors

OptionOpt

Fields

• _oLong :: Maybe String
• _oShort :: Maybe Char
• _oHelp :: Maybe String
• _oMetavar :: Maybe String
• _oEnvVar :: Maybe String
• _oDefaultVal :: Maybe a
• _oDefaultStr :: Maybe String
• _oReader :: OptReader a

data FlagOpt (attr :: [OptAttr]) a

Option for flags that act like switches between a default and an active value. Corresponds to flag.

Constructors

FlagOpt

Fields

• _fLong :: Maybe String
• _fShort :: Maybe Char
• _fHelp :: Maybe String
• _fEnvVar :: Maybe String
• _fDefaultVal :: a
• _fReader :: OptReader a
• _fActive :: a

data ArgumentOpt (attr :: [OptAttr]) a

Option for arguments (no long/short specifiers). Corresponds to argument.

Constructors

ArgumentOpt

Fields

• _aHelp :: Maybe String
• _aMetavar :: Maybe String
• _aEnvVar :: Maybe String
• _aDefaultVal :: Maybe a
• _aDefaultStr :: Maybe String
• _aReader :: OptReader a

data OptAttr

Constructors

OptDefault

OptOptional

data OptType a

Option types

Constructors

OptionOptType

FlagOptType a

a is the active value for the flag parser

ArgumentOptType

Instances

Functor OptType

Defined in Options.Harg.Types

Methods

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

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

data SomeOpt where

Existential wrapper for Opt, so that many options can be carried in a list.

Constructors

SomeOpt :: Opt a -> SomeOpt

type OptReader a = String -> Either String a

data HargCtx

Context to carry around, that contains environment variables and command line arguments.

Constructors

HargCtx

Fields

• _hcEnv :: Environment
• _hcArgs :: Args

type Environment = [(String, String)]

Environment variable pairs, can be retrieved with getEnvironment.

getCtx :: IO HargCtx

ctxFromArgs :: Args -> IO HargCtx

ctxFromEnv :: Environment -> IO HargCtx

pureCtx :: Environment -> Args -> HargCtx