document all control exception types.

[coke]

These were meant to correspond to HLL flow control, like tcl's [break] and [continue], but it seems that CONTROL_LOOP_NEXT and CONTROL_LOOP_LAST were added as well (and those are in use by NQP, etc.).

I don't particularly care which pair we keep, but having both sets is wrong.

Originally http://trac.parrot.org/parrot/ticket/1339

[tene]

19:40 <+dalek> TT #1339 created by coke++: eliminate redundant exceptions CONTROL_CONTINUE and CONTROL_BREAK 19:41 <@tene> Coke: in Perl 6, at least, break is different from last 19:41 <@coke> ... how? 19:42 <@tene> break is used to exit the innermost containing construct that sets $_ 19:42 <@tene> like a 'given' block. 19:43 <@tene> and 'continue' is used to fall out of a 'when' block without throwing a 'break' exception. 19:43 <@coke> "fall out" ? 19:43 <@DukeLeto> Tene,Coke: Thanks guys, you got me unstuck! 19:43 <@tene> Perl 6 'when' blocks end with an implied 'break' 19:43 <@coke> (makes it sound like break again.)] 19:43 <@coke> Tene: I think your break is not my break. 19:44 <@tene> so: when 1 { do stuff; } default { do more stuff; } 19:44 <@tene> the 'default' doesn't get executed. 19:44 <@tene> but: when 1 { do stuff; continue; } default { do more stuff; } 19:44 <@tene> the default block does get executed 19:44 <@coke> that continue is also not like my continue. 19:45 <@tene> So the tcl continue/break are the Perl 6 next/last 19:45 <@coke> so you can keep break and continue, I suppose, but the way you describe them there are useless to me. 19:45 <@coke> just annoying that I "reserved" them and they were co-opted. :P 19:45 <@tene> It's not the first time that things have different names in tcl and perl 6 19:45 <@coke> be nice if these were documented. =-) 19:45 <@tene> Where would you expect to find that? 19:46 <@coke> runtime/parrot/include/except_types.pasm 19:46 <@tene> Oh! I know! I'll document it in the ticket rejection! 19:46 <@coke> or perhaps in the C enum that generated it. 19:46 <@tene> that should be sufficient, right? 19:46 <@coke> but the .pasm is the file I'm actually using. 19:46 <@coke> necessary but not sufficient.

[coke]

The "proper" uses for these control exceptions needs to be documented, as my initial tcl-style versions have been co-opted by the perl6 meanings.