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Postings from May 2007
At 5:00 PM -0700 5/14/07, Darren Duncan wrote: >On the other hand, unless this steps on something, I could suggest >dropping the @ and % anyway, so we have $array and $hash, and then >we could instead use the @ and % sigils as a prefix to indicate in >that case that we want them to copy by value. For example: > > my $foo = [23, 434, 6]; > my $bar; > $bar = $foo; # copy by reference > @$bar = @$foo; # copy by value > >Actually, I think that would be a vast improvement, as we could then >use the @ prefix with any collection type as short-hand to say that >= is copy by value. As a follow-up or clarification of what I just said, here is a proposal ... Variables of all types have $ sigils. The semantics of $foo = $bar are unchanged; usually $foo and $bar point to the same container after the assignment, afaik. Prefixing a @ or % before a variable name indicates a syntactic short-hand for something concerning the variable. On declaration, saying @$foo means the same as "Array $foo", and saying %$foo means the same as "Hash $foo", or some such. This works for my|our|has etc as well as parameter declarations. This is instead of declaring @foo or %foo. On use in an expression, @$foo = @$bar indicates we want a copy by value or clone or shallow copy or whatever, and $foo and $bar point to different containers after the assignment; the semantics are like the current @foo = @bar. Similarly, use eg @@$foo rather than @@foo as appropriate. With these changes, I see it making Perl more consistent in appropriate ways, and easier to use, and huffmanizing isn't worse. Also, it means we can free up the @ and % rare ASCII symbols for other purposes in some situations. I could also argue that the conception of @ meaning plural vs $ singular isn't really an absolute, since any value can be treated as either being a collection or being atomic under different circumstances. -- Darren Duncan