Extend Option with argRequired and argOptional

[shadowspawn]

Pull Request

Fill out the Option methods to allow explicit configuration as alternative to implicit syntax from string.

This is not likely to be used much, and some downsides to having two ways to do something! Trying out an idea.

Method naming is intended to work with Argument too.

Problem

The syntax for required (<arg>) and optional ([arg]) option-arguments needs to be learned. (However, this is consistent with the syntax shown in the help so is useful to learn!)

Related: #665 #1359 (comment)

Solution

Add .argRequired() and .argOptional() to Option.

Adding for completeness, and not planning to add this to README for now.

ChangeLog

• add Option methods for .argRequired() and .argOptional() as alternative way of specifying option-argument

[shadowspawn]

Happy with this as a proof of concept, but not sure it is worthwhile unless some demand.

Going to try similar pattern for Argument, where it should be simpler. (e.g. keep argument name separate)

Closing this for now.