Options.Applicative.Extra · optparse-applicative-0.18.1.0

valuehelper :: Parser (a -> a)

A hidden "helper" option which always fails.

A common usage pattern is to apply this applicatively when creating a ParserInfo

opts :: ParserInfo Sample
opts = info (sample <**> helper) mempty

valuehelperWith :: Mod OptionFields (a -> a) -> Parser (a -> a)

#

Like helper, but with a minimal set of modifiers that can be extended as desired.

opts :: ParserInfo Sample
opts = info (sample <**> helperWith (mconcat [
         long "help",
         short 'h',
         help "Show this help text",
         hidden
       ])) mempty

valuehsubparser :: Mod CommandFields a -> Parser a

#

Builder for a command parser with a "helper" option attached. Used in the same way as subparser, but includes a "--help|-h" inside the subcommand.

valuesimpleVersioner

:: String
Version string to be shown
-> Parser (a -> a)

#

A hidden "--version" option that displays the version.

opts :: ParserInfo Sample
opts = info (sample <**> simpleVersioner "v1.2.3") mempty

valueexecParser :: ParserInfo a -> IO a

#

Run a program description.

Parse command line arguments. Display help text and exit if any parse error occurs.

valuecustomExecParser :: ParserPrefs -> ParserInfo a -> IO a

#

Run a program description with custom preferences.

valueexecParserPure

:: ParserPrefs
Global preferences for this parser
-> ParserInfo a
Description of the program to run
-> [String]
Program arguments
-> ParserResult a

#

The most general way to run a program description in pure code.

valuegetParseResult :: ParserResult a -> Maybe a

#

Extract the actual result from a ParserResult value.

This function returns Nothing in case of errors. Possible error messages or completion actions are simply discarded.

If you want to display error messages and invoke completion actions appropriately, use handleParseResult instead.

valuehandleParseResult :: ParserResult a -> IO a

#

Handle ParserResult.

valueparserFailure

#

Generate a ParserFailure from a ParseError in a given Context.

This function can be used, for example, to show the help text for a parser:

handleParseResult . Failure $ parserFailure pprefs pinfo (ShowHelpText Nothing) mempty

valuerenderFailure :: ParserFailure ParserHelp -> String -> (String, ExitCode)

#

newtypenewtype ParserFailure h

#

Constructors

ParserFailure
- execFailure :: String -> (h, ExitCode, Int)

Instances2Functor, Show

Functor ParserFailureDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types
Show h => Show (ParserFailure h)Defined in optparse-applicative-0.18.1.0 · Options.Applicative.Types

valueoverFailure

#

datadata ParserResult a

#

Result of execParserPure.

Constructors

Instances4Monad, Functor, Applicative, Show

Monad ParserResultDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types
Functor ParserResultDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types
Applicative ParserResultDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types
Show a => Show (ParserResult a)Defined in optparse-applicative-0.18.1.0 · Options.Applicative.Types

datadata ParserPrefs

#

Global preferences for a top-level Parser.

Constructors

ParserPrefs
- prefMultiSuffix :: String
  metavar suffix for multiple options
- prefDisambiguate :: Bool
  automatically disambiguate abbreviations (default: False)
- prefShowHelpOnError :: Bool
  always show help text on parse errors (default: False)
- prefShowHelpOnEmpty :: Bool
  show the help text for a command or subcommand if it fails with no input (default: False)
- prefBacktrack :: Backtracking
  backtrack to parent parser when a subcommand fails (default: Backtrack)
- prefColumns :: Int
  number of columns in the terminal, used to format the help page (default: 80)
- prefHelpLongEquals :: Bool
  when displaying long names in usage and help, use an = sign for long names, rather than a single space (default: False)
- prefHelpShowGlobal :: Bool
  when displaying subparsers' usage help, show parent options under a "global options" section (default: False)
- prefTabulateFill :: Int
  Indentation width for tables

Instances2Eq, Show

Eq ParserPrefsDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types
Show ParserPrefsDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types

newtypenewtype CompletionResult

#

Constructors

CompletionResult
- execCompletion :: String -> IO String

Instances1Show

Show CompletionResultDefined in optparse-applicative-0.18.1.0 · Options.Applicative.Types

Extra parser utilities

Constructors

Constructors

Constructors

Constructors