optparse-applicative-0.8.1: Utilities and combinators for parsing command line options

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Options.Applicative.Extra

Contents

Synopsis

Extra parser utilities

This module contains high-level functions to run parsers.

helper :: Parser (a -> a)Source

A hidden "helper" option which always fails.

execParser :: ParserInfo a -> IO aSource

Run a program description.

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

execParserMaybe :: ParserInfo a -> [String] -> Maybe aSource

Run a program description in pure code.

This function behaves like execParser, but can be called from pure code. Note that, in case of errors, no message is displayed, and this function simply returns Nothing.

If you need to keep track of error messages, use execParserPure instead.

customExecParser :: ParserPrefs -> ParserInfo a -> IO aSource

Run a program description with custom preferences.

customExecParserMaybe :: ParserPrefs -> ParserInfo a -> [String] -> Maybe aSource

Run a program description with custom preferences in pure code.

See execParserMaybe for details.

execParserPureSource

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.

newtype ParserFailure Source

Constructors

ParserFailure 

data ParserResult a Source

Result of execParserPure.

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)

prefBacktrack :: Bool

backtrack to parent parser when a subcommand fails (default: True)

prefColumns :: Int

number of columns in the terminal, used to format the help page (default: 80)