[NTG-context] How to extend an existing macro to take optional parameters?

[Alan Braslau]

Designating "optional" parameters within [...] is a LaTeX notion.
ConTeXt handles parameters differently.

Alan


> > and I'd like to be able to extend it so that any of the following
> > can be used:
> > 
> >    \mycommand{aa}{bb}{cc}
> >    \mycommand{aa}{bb}{cc}{dd}
> >    \mycommand{aa}{bb}{cc}{dd}[ee]
> > 
> > or
> > 
> >    \mycommand[ee]{aa}{bb}{cc}{dd}  % if this is more the ConTeXt way
> > 
> > where {dd} is the optional extra parameter and, if it is present,
> > then [ee] can also be optionally added (because it controls how
> > {dd} is printed).