System.Console.Argument

Documentation

data Type a

Constructors

Type

Fields

parser :: String -> String -> Either String a

name :: String

defaultValue :: Maybe a

Instances

Functor Type

Argument types

optional

Arguments

:: a

Default value.

-> Type a

-> Type a

string :: Type String

A plain string.

boolean :: Type Bool

A boolean. Argument can be "1","0","true","false","on","off".

directory :: Type FilePath

A directory path. A trailing slash is stripped, if present.

file :: Type FilePath

A file path.

device :: Type FilePath

A device path.

natural :: Type Integer

A natural number (in decimal).

integer :: Type Integer

An integer number (in decimal).

Option descriptions

option

Arguments

:: (a -> s)

Function that creates a setting (of type s) from the option argument.

-> [Char]

List of short option characters.

-> [String]

List of long option strings.

-> Type a

Type of option argument.

-> String

Description.

-> OptDescr (Either String s)

The resulting option description.

Create an option description.