Re: support for built-in -opt style options for proc

In the end I used teapam. For example:

package require tepam

namespace eval dialog {}

tepam::procedure {dialog prepare} {
    -named_arguments_first 0
    -args {
        {-modeless -type none}
        {-parent -default .}
        {window}
    }
} {
    wm withdraw $window
    wm attributes $window -type dialog
    if {!$modeless} { wm transient $window $parent }
}

I also used it for show and hide functions so that 'dialog' is an ensemble
command.

It is a pity the docs lack egs but in the end I found it fairly easy to
use.