sub makeclosure {
 my @x=(@_);
 return sub {
  return @x
 }
}
sub yoursubhere{
#do stuff
return makeclosure(val1,val2);
#on error
return bless sub {undef or die},"errormessage";

##</code><code>##

if(ref($return=&yoursubhere($a->(),$s->())ne"CODE"){
#error
}
&nextsub($return->())