> > Here the first/last values appear at the end. The second argument > > appears to be the Tcl interpreter (from Tcl.pm). The third > argument is > > some sort of blessed reference to the subroutine being called, > > although > > the stringification is unusual. I have no idea why there's a leading > > undef value, or what it's supposed to be a placeholder for. The > > documentation only states that you can pass a CODE reference to a > > callback. It says nothing about what the arguments are. > > Right. The 3 first arguments are basically junk. Functions passed > this way should really start out with doing a splice(@_, 0, 3) :-(
Indeed. IMO the design of this dates back to Malcolm Beattie's implementation. > My preference would be to change this interface so that the 3 first > args were always chopped. That would make passing [\&foo] and \&foo > have exactly the same behaviour. The best way to fix this would > actually be on the Tcl.pm side, but if this isn't acceptable > Tkx could > always preprocess the arguments it pass to rewrite \&foo into > [\&foo]. I would not document this until we figured out how/if we > want to fix this. this will break existing code. But IMO that's acceptable, because, as it seems to me, no-one really used such callbacks in real life. Changing this will require some sort of sycnhronization between the dependant modules (namely Tcl::Tk and Tkx). Best regards, Vadim.
