Env.Internal.Parser

An environment parser

Try to parse a pure environment

This represents a modification of the properties of a particular Parser. Combine them using the Monoid instance.

The string to prepend to the name of every declared environment variable

Parse a particular variable from the environment

>>> var str "EDITOR" (def "vim" <> helpDef show)

Environment variable metadata

An environment variable's value parser. Use (<=<) and (>=>) to combine these

Create a Reader from a simple parser function

The trivial reader

The single character string reader

The reader that accepts only non-empty strings

The reader that splits a string into a list of strings consuming the separator.

The reader that uses the Read instance of the type

The default value of the variable

Note: specifying it means the parser won't ever fail.

Show the default value of the variable in help.

Use the Show instance to show the default value of the variable in help.

A flag that takes the active value if the environment variable is set and non-empty and the default value otherwise

Note: this parser never fails.

A simple boolean flag

Note: this parser never fails.

Flag metadata

A class of things that can have a help message attached to them

Attach help text to the variable

Mark the enclosed variables as sensitive to remove them from the environment once they've been parsed successfully.