On Thu, Sep 22, 2005 at 07:23:06 -0400, David Storrs wrote: > > On Sep 22, 2005, at 3:08 AM, Luke Palmer wrote: > > >On 9/22/05, Carl Mäsak <[EMAIL PROTECTED]> wrote: > >>FWIW, to me it looks fairly intuitive. undef here means "don't alias > >>the element, just throw it away"... gaal joked about using _ instead > >>of undef. :) > >Joked? Every other language that has pattern matching signatures that > >I know of (that is, ML family and Prolog) uses _. Why should we break > >that? >
> Because the way Carl has it is more consistent with Perl 5, from
> whence most of our users will be coming?
But not with MMD pattern matching stuff, since you are now allowed
to declare that a body behaves a certain way when receiving certain
values.. For example
multi factorial (0) { 1 }
multi factorial ($n) { $n * factorial($n -1) }
I find this approach much more intuitive than special casing the
behavior of certain values when they are used inside prototypes.
> Because 'undef' has a nice visual weight, while '_' can all too
> easily disappear?
sub foo ($x, _, $y) { # i feel this has a big enough weigh
sub foo ($x, __, $y) { # even better
> Because throwing away values is something that we probably
> shouldn't make too easy?
It should be made very easy - this encourages reuse of calling code,
not only callee code.
--
() Yuval Kogman <[EMAIL PROTECTED]> 0xEBD27418 perl hacker &
/\ kung foo master: *shu*rik*en*sh*u*rik*en*s*hur*i*ke*n*: neeyah!!!!
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