On Wed, May 08, 2013 at 10:58:02AM -0700, fe...@crowfix.com wrote: > On Wed, May 08, 2013 at 09:43:27AM -0700, Bill Ward wrote: > > Cool. That whole scalar vs list context thing is one of Perl's biggest > > strengths, but also one of its biggest weaknesses (in that it is a common > > source of bugs like this). When you see head-scratching problems, it's one > > of the first things to look for. > > Just guessing here, not familiar with the particular code in question. > But I have been bitten a few times by code which returns false in the > 'proper' manner > > return; > > instead of forcing a scalar return > > return undef; > > or list return > > return ();
There is no difference between "return;" and "return ();". Both return an empty list when called in list context and an undef when called in scalar context. The "return ();" style does serve as a reminder to the reader. > Is that what's going on here -- the original code imparted a list > context, which triggered another perl gotcha, whereby missing list > values simply disappear: > > scalar(1,2,,4,,6) ---> 4, not 6 That returns 6, or rather, it returns whatever happens to be the last value. Tim.
