Safe Haskell	Safe-Inferred
Language	Haskell98

Options.Applicative.Extra

Contents

Extra parser utilities

Synopsis

helper :: Parser (a -> a)
helperWith :: Mod OptionFields (a -> a) -> Parser (a -> a)
hsubparser :: Mod CommandFields a -> Parser a
execParser :: ParserInfo a -> IO a
customExecParser :: ParserPrefs -> ParserInfo a -> IO a
execParserPure :: ParserPrefs -> ParserInfo a -> [ String ] -> ParserResult a
getParseResult :: ParserResult a -> Maybe a
handleParseResult :: ParserResult a -> IO a
parserFailure :: ParserPrefs -> ParserInfo a -> ParseError -> [ Context ] -> ParserFailure ParserHelp
renderFailure :: ParserFailure ParserHelp -> String -> ( String , ExitCode )
newtype ParserFailure h = ParserFailure {
- execFailure :: String -> (h, ExitCode , Int )
}
overFailure :: ( ParserHelp -> ParserHelp ) -> ParserResult a -> ParserResult a
data ParserResult a
- = Success a
- | Failure ( ParserFailure ParserHelp )
- | CompletionInvoked CompletionResult
data ParserPrefs = ParserPrefs {
- prefMultiSuffix :: String
- prefDisambiguate :: Bool
- prefShowHelpOnError :: Bool
- prefShowHelpOnEmpty :: Bool
- prefBacktrack :: Backtracking
- prefColumns :: Int
- prefHelpLongEquals :: Bool
- prefHelpShowGlobal :: Bool
- prefTabulateFill :: Int
}
newtype CompletionResult = CompletionResult {
- execCompletion :: String -> IO String
}

Extra parser utilities

This module contains high-level functions to run parsers.

helper :: Parser (a -> a) Source #

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

helperWith :: Mod OptionFields (a -> a) -> Parser (a -> a) Source #

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

hsubparser :: Mod CommandFields a -> Parser a Source #

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.

execParser :: ParserInfo a -> IO a Source #

Run a program description.

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

customExecParser :: ParserPrefs -> ParserInfo a -> IO a Source #

Run a program description with custom preferences.

execParserPure Source #

Arguments

:: 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.

getParseResult :: ParserResult a -> Maybe a Source #

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.

handleParseResult :: ParserResult a -> IO a Source #

Handle ParserResult .

parserFailure :: ParserPrefs -> ParserInfo a -> ParseError -> [ Context ] -> ParserFailure ParserHelp Source #

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 mempty

renderFailure :: ParserFailure ParserHelp -> String -> ( String , ExitCode ) Source #

newtype ParserFailure h Source #

Constructors

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

Instances

Instances details

Functor ParserFailure Source #
Instance details Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserFailure a -> ParserFailure b Source # (<$) :: a -> ParserFailure b -> ParserFailure a Source #
Show h => Show ( ParserFailure h) Source #
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> ParserFailure h -> ShowS Source # show :: ParserFailure h -> String Source # showList :: [ ParserFailure h] -> ShowS Source #

overFailure :: ( ParserHelp -> ParserHelp ) -> ParserResult a -> ParserResult a Source #

data ParserResult a Source #

Result of execParserPure .

Constructors

Success a
Failure ( ParserFailure ParserHelp )
CompletionInvoked CompletionResult

Instances

Instances details

Monad ParserResult Source #
Instance details Defined in Options.Applicative.Types Methods (>>=) :: ParserResult a -> (a -> ParserResult b) -> ParserResult b Source # (>>) :: ParserResult a -> ParserResult b -> ParserResult b Source # return :: a -> ParserResult a Source #
Functor ParserResult Source #
Instance details Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserResult a -> ParserResult b Source # (<$) :: a -> ParserResult b -> ParserResult a Source #
Applicative ParserResult Source #
Instance details Defined in Options.Applicative.Types Methods pure :: a -> ParserResult a Source # (<>) :: ParserResult (a -> b) -> ParserResult a -> ParserResult b Source # liftA2 :: (a -> b -> c) -> ParserResult a -> ParserResult b -> ParserResult c Source # (>) :: ParserResult a -> ParserResult b -> ParserResult b Source # (<*) :: ParserResult a -> ParserResult b -> ParserResult a Source #
Show a => Show ( ParserResult a) Source #
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> ParserResult a -> ShowS Source # show :: ParserResult a -> String Source # showList :: [ ParserResult a] -> ShowS Source #

data ParserPrefs Source #

Global preferences for a top-level Parser .

Constructors

ParserPrefs

Fields

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

Instances

Instances details

Eq ParserPrefs Source #
Instance details Defined in Options.Applicative.Types Methods (==) :: ParserPrefs -> ParserPrefs -> Bool Source # (/=) :: ParserPrefs -> ParserPrefs -> Bool Source #
Show ParserPrefs Source #
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> ParserPrefs -> ShowS Source # show :: ParserPrefs -> String Source # showList :: [ ParserPrefs ] -> ShowS Source #

newtype CompletionResult Source #

Constructors

CompletionResult
Fields execCompletion :: String -> IO String

Instances

Instances details

Show CompletionResult Source #
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> CompletionResult -> ShowS Source # show :: CompletionResult -> String Source # showList :: [ CompletionResult ] -> ShowS Source #