Modulererebase-1.21.2Haskell2010

System.Console.GetOpt

3 types
3 values

Packagererebase-1.21.2
Exports6
LanguageHaskell2010
LicenceMIT
SourceGetOpt.hs

datadata ArgDescr a

Describes whether an option takes an argument or not, and if so how the argument is injected into a value of type a.

Constructors

NoArg a
no argument expected
ReqArg (String -> a) String
option requires argument
OptArg (Maybe String -> a) String
optional argument

Instances2Functor, Invariant

Functor ArgDescrDefined in base-4.20.2.0 · System.Console.GetOpt
Invariant ArgDescrDefined in invariant-0.6.4 · Data.Functor.Invariant
from System.Console.GetOpt

datadata ArgOrder a

What to do with options following non-options

Constructors

RequireOrder
no option processing after first non-option
Permute
freely intersperse options and non-options
ReturnInOrder (String -> a)
wrap non-options into options

Instances2Functor, Invariant

Functor ArgOrderDefined in base-4.20.2.0 · System.Console.GetOpt
Invariant ArgOrderDefined in invariant-0.6.4 · Data.Functor.Invariant
from System.Console.GetOpt

datadata OptDescr a

Each OptDescr describes a single option.

The arguments to Option are:

list of short option characters
list of long option strings (without "--")
argument descriptor
explanation of option for user

Constructors

Option [Char] [String] (ArgDescr a) String

Instances2Functor, Invariant

Functor OptDescrDefined in base-4.20.2.0 · System.Console.GetOpt
Invariant OptDescrDefined in invariant-0.6.4 · Data.Functor.Invariant
from System.Console.GetOpt

valuegetOpt

:: ArgOrder a
-> [OptDescr a]
-> [String]
-> ([a], [String], [String])

Process the command-line, and return the list of values that matched (and those that didn't). The arguments are:

The order requirements (see ArgOrder)
The option descriptions (see OptDescr)
The actual command line arguments (presumably got from getArgs).

getOpt returns a triple consisting of the option arguments, a list of non-options, and a list of error messages.

valuegetOpt'

:: ArgOrder a
-> [OptDescr a]
-> [String]
-> ([a], [String], [String], [String])

This is almost the same as getOpt, but returns a quadruple consisting of the option arguments, a list of non-options, a list of unrecognized options, and a list of error messages.

valueusageInfo :: String -> [OptDescr a] -> String

Return a string describing the usage of a command, derived from the header (first argument) and the options described by the second argument.