abbreviate 'do { $@="blah blah"; return undef; };

[iaw4]

dear perl monks: I would like to mimick eval in its return scheme: $@ stores a message, and the routine returns undef; right now, I am writing

  (cond1 && cond2) and do { $@="message"; return; };

looks ugly. what I would prefer is

  (cond1 && cond2) and signalerror "message";

of course, the problem is that a sub signalerror returning undef will not return one level up. I could write something like

  (cond1 && cond2) and return signalerror "message";

but at this point, my syntax looks about as painful. is there a way to coax perl to expand signalerror into $@=message and then return undef? /iaw

[Corion]

I would opt for your last version, but there also is Scope::Upper::unwind, which lets you return from the perspective of the caller. Not that I really advocate messing with the control flow outside of Perls primitives.

What's your problem with calling die or croak?

[stonecolddevin]

Check out Try::Tiny

[JavaFan]

return if cond1 and cond2 and $@ = "message";

[tobyink]

s/signalerror/die/

OK, so it's not quite what you want, but it's more likely to be what people calling your code will expect.