On Sun, 18 Mar 2007, Aaron Crane wrote: > David Green writes: > > In the meantime, Darren's proposal still raises a lot of interesting > > language questions. For example, how *do* you rename a hash key? > > That's easy even in Perl 5. This modifies %hash in-place: > > my @values = delete @[EMAIL PROTECTED]; > @[EMAIL PROTECTED] = @values; > > While there's certainly motivation to wrap this up in a function or > operator, it doesn't strike me as something particularly difficult, or > necessarily more worthy of inclusion in Perl 6.0.0 than anything else.
Actually, what I proposed is more complicated than that. Any key-renames such as I propose need to be non-colliding. If %hash contained keys a,b,c and @old_names was a and @new_names was b, then the above code would overwrite the existing b element, and leave 2 elements total. The operation I proposed needs to fail when one requests a colliding element, such as that situation; a successful operation will leave a Hash that is identical but for the element key changes; there would be the same number of elements and they have the same values. So if a short-hand syntax existed, it would be replacing more complicated code than that. -- Darren Duncan
