Front page | perl.perl5.porters |
Postings from January 2001
>>>>> "TB" == Tim Bunce <Tim.Bunce@ig.co.uk> writes: TB> On Wed, Jan 10, 2001 at 09:36:51PM -0800, Stephen McCamant wrote: SMcC> =item Can't return %s to lvalue scalar context SMcC> (F) You tried to return a complete array or hash from an lvalue SMcC> subroutine, but you called the subroutine in a way that made SMcC> Perl think you meant to return only one value. You probably SMcC> meant to write parentheses around the call to the subroutine, SMcC> which tell Perl that the call should be in list context. TB> But TB> (sub_returning_lvalue_hash()) = 1; TB> would be rather odd and, I hope, generate an 'odd number of elements in TB> hash assignment' error. It's a warning rather than an error, but yes. TB> And TB> (sub_returning_lvalue_array()) = 1; TB> could perhaps be better written as TB> sub_returning_lvalue_array() = (1); TB> (I'm not sure if that'll work as I'd expect, I've not been following TB> too closely.) No, unfortunately it won't work as you expect. The current operation of lvalue subroutines follows the same rules as for scalars, which means the operative difference is the presence or absence of parens on the left side. (Just like `$x = (1, 2, 3)' is still a scalar assignment). TB> So I'd suggest that the docs suggest writing parentheses around TB> the _value_ rather than the call. I'm not particularly fond of the current lvalue subroutine context semantics, but I don't really have anything better to suggest (except maybe always forcing list context, but that seems like a step backwards). -- Stephen McCThread Previous | Thread Next