Changes

In ConTeXt, the optional argument processing is handled as a two-step process. First, we write the command for the end-user as a wrapper command, which calls {{cmd|dodoubleempty}} (from {{src|syst-aux.mkiv}} or {{src|syssyst-gen.mkii}}) to handle the arguments properly -- including the optional ones -- and then calls a "private" command that contains the internals of the macro. Note that this function call does not explicitly refer to the arguments at all.