option package:optparse-applicative

Builder for an option using the given reader. This is a regular option, and should always have either a long or short name specified in the modifiers (or both).

nameParser = option str ( long "name" <> short 'n' )

A single option of a parser.

An option that always fails. When this option is encountered, the option parser immediately aborts with the given parse error. If you simply want to output a message, use infoOption instead.

Intersperse matched options and arguments normally, but allow unmatched options to be treated as positional arguments. This is sometimes useful if one is wrapping a third party cli tool and needs to pass options through, while also providing a handful of their own options. Not recommended in general as typos by the user may not yield a parse error and cause confusion.

An option that always fails and displays a message.

Group options together under a common heading in the help text. For example, if we have:

Args
<$> parseMain
<*> parserOptionGroup "Group A" parseA
<*> parserOptionGroup "Group B" parseB
<*> parseOther

Then the help page will look like:

Available options:
<main options>
<other options>

Group A
<A options>

Group B
<B options>

Builder for an option taking a String argument.

Options to influence the layout algorithms.

The default layout options, suitable when you just want some output, and don’t particularly care about the details. Used by the Show instance, for example.

>>> defaultLayoutOptions
LayoutOptions {layoutPageWidth = AvailablePerLine 80 1.0}

Maps an Option modifying function over the Parser.

Options and arguments can be interspersed, but if a given option is not found, it is treated as a positional argument. This is sometimes useful if one is passing through most options to another tool, but are supplying just a few of their own options.