OptEnvConf.Setting

A setting for parsing and documenting a single value.

Document a setting

Multiple helps concatenate help on new lines.

Document an option or env var.

Multiple metavars override eachother.

Try to parse an argument.

You'll also need to add a reader.

Multiple arguments are redundant.

Try to parse an argument.

You'll also need to add a reader, at least one long or short, and a metavar.

Multiple options are redundant.

Try to parse a switch, activate the given value when succesful

You'll also need to add at least one long or short.

Multiple switchs override eachother.

Declare how to parse an argument, option, or environment variable.

Read a string as-is.

This is the reader you will want to use for reading a String.

This is different from auto for strings because Read wants to parse quotes when parsing Strings.

Read via the Read instance

You cannot use this for bare strings, because Read for strings parses quotes.

Try to parse this long option or switch.

long "foo" corresponds to --foo

Notes: * Parsing options with an empty name in the long is not supported. * Parsing options with an = sign in the long is not supported.

Multiple longs will be tried in order. Empty longs will be ignored.

Try to parse this short option or switch.

short f corresponds to -f

Notes: * Parsing options with short - is not supported.

Multiple shorts will be tried in order.

Try to parse an environment variable.

You'll also need to add a reader and a metavar.

Multiple envs will be tried in order.

Like env but ignores any subEnv, subEnv_, or subAll.

Try to parse a configuration value at the given key.

Multiple confs will be tried in order.

Like conf but with a custom Codec for parsing the value.

Like confWith but allows interpreting Null as a value other than "Not found".

Like conf but ignores any subConf, subConf_, or subAll.

Like confWith but ignores any subConf, subConf_, or subAll.

Like confWith' but ignores any subConf, subConf_, or subAll.

Short-hand function for option, long, env, and conf at the same time.

Multiple names will be tried in order.

Set the default value

Multiple values override eachother.

API Note: default is not a valid identifier in Haskell. I'd also have preferred default instead.

Set the default value, along with version of it shown by a custom function.

Provide an example value for documentation.

The example is provided as a literal string.

If you use reader auto, you'll want to use shownExample instead.

Use Show to show an example.

This only makes sense if you use reader auto.

Don't show this setting in documentation

Multiple hiddens are redundant.

Set the setting to tab-complete with the given completer

Multiple completers are redundant.

Builder for a Setting

Show a Setting as much as possible, for debugging

Complete a Builder into a Setting

A mempty Setting to build up a setting from.