Richard Suchenwirth 2007-09-28 - Since Tcl 8.5 gives us the apply command, it is possible to remodel part (or even all?) of the proc functionality in its terms, in a devilish cascade of interp alias and apply:
interp alias {} proc {} \ apply {{name argl body} {interp alias {} $name {} apply [list $argl $body]}}
We define an alias named proc, which overrides the built-in command, to apply to a {name argl body} triplet a codelet that defines an alias name to apply to the argl the body. Whew...
Testing (should print 49/a-b-c, did for me):
proc square {x {y ""}} {if {$y eq ""} {set y $x}; expr {$x*$y}} proc foo args {join $args -} puts [square 7]/[foo a b c]