Safe Haskell	None
Language	Haskell98

Options.Applicative.Simple

Description

Simple interface to program arguments.

Typical usage with no commands:

do (opts,()) <-
     simpleOptions "ver"
                   "header"
                   "desc"
                   (flag () () (long "some-flag"))
                   empty
   doThings opts

Typical usage with commands:

do (opts,runCmd) <-
     simpleOptions "ver"
                   "header"
                   "desc"
                   (pure ()) $
     do addCommand "delete"
                   "Delete the thing"
                   (const deleteTheThing)
                   (pure ())
        addCommand "create"
                   "Create a thing"
                   createAThing
                   (strOption (long "hello"))
   runCmd

Synopsis

Documentation

simpleOptions #

Arguments

:: String	version string
-> String	header
-> String	program description
-> Parser a	global settings
-> EitherT b (Writer (Mod CommandFields b)) ()	commands (use `addCommand`)
-> IO (a, b)

Generate and execute a simple options parser.

simpleVersion :: Version -> Q Exp #

Generate a string like Version 1.2, Git revision 1234.

$(simpleVersion …) :: String

addCommand #

Arguments

:: String	command string
-> String	title of command
-> (a -> b)	constructor to wrap up command in common data type
-> Parser a	command parser
-> EitherT b (Writer (Mod CommandFields b)) ()

Add a command to the options dispatcher.

addSubCommands #

Arguments

:: String	command string
-> String	title of command
-> EitherT b (Writer (Mod CommandFields b)) ()	sub-commands (use `addCommand`)
-> EitherT b (Writer (Mod CommandFields b)) ()

Add a command that takes sub-commands to the options dispatcher.

Example:

addSubCommands "thing"
               "Subcommands that operate on things"
               (do addCommand "delete"
                              "Delete the thing"
                              (const deleteTheThing)
                              (pure ())
                   addCommand "create"
                              "Create a thing"
                              createAThing
                              (strOption (long "hello")))

If there are common options between all the sub-commands, use addCommand in combination with simpleParser instead of addSubCommands.

simpleParser #

Arguments

:: Parser a	common settings
-> EitherT b (Writer (Mod CommandFields b)) ()	commands (use `addCommand`)
-> Parser (a, b)

Generate a simple options parser.

Most of the time you should use simpleOptions instead, but simpleParser can be used for sub-commands that need common options. For example:

addCommand "thing"
           "Subcommands that operate on things"
           (\(opts,runSubCmd) -> runSubCmd opts)
           (simpleParser (flag () () (long "some-flag")) $
            do addCommand "delete"
                          "Delete the thing"
                          (const deleteTheThing)
                          (pure ())
               addCommand "create"
                          "Create a thing"
                          createAThing
                          (strOption (long "hello")))

module Options.Applicative