Argon: an alternative parser for command-line arguments

[Victor Porton]

On Wednesday, 9 March 2016 at 18:56:10 UTC, Markus Laker wrote:
> To support git-style syntax while using Argon, I'd do this:
>
> 1. Find the (possibly empty) initial sequence of tokens that 
> start with a dash.  Pass them to an Argon-derived class which 
> we'll call `Stem', which parses them.
>
> 2. If no more tokens exist (as in "my-command --help"), do what 
> we can with the options we've seen, and then exit.
>
> 3. Otherwise, the next token must be a subcommand name: we've 
> seen something "my-command --verbose display-widgets 
> --paginate".
>  Use that token to select a leaf class, also derived from 
> Argon.  There's one leaf class per subcommand.
>
> 4. Pass the remaining tokens (in this example, just 
> "--paginate") to the selected leaf pass for parsing.  Also pass 
> a reference to Stem, so that the leaf code can use any options 
> garnered by Stem.

It is a wrong way, because switches may have arguments (not 
starting with a dash).

I am now considering to write a new object-oriented command line 
parser from scratch because it is sometimes easier to write new 
code than to understand other's one.

> It shouldn't be hard to write some reusable code to do this, if 
> it were a common requirement.