Front page | perl.perl6.language |
Postings from January 2004
----- Original Message -----
From: "Luke Palmer" <fibonaci@babylonia.flatirons.org>
To: "Austin Hastings" <Austin_Hastings@Yahoo.com>
Cc: "Larry Wall" <larry@wall.org>; "Language List" <perl6-language@perl.org>
Sent: Thursday, January 22, 2004 4:28 PM
Subject: [perl] Re: Semantics of vector operations
> Austin Hastings writes:
> > How do you handle operator precedence/associativity?
> >
> > That is,
> >
> > $a + $b + $c
> >
> > If you're going to vectorize, and combine, then you'll want to group. I
> > think making the vectorizer a grouper as well kills two birds with one
> > stone.
> >
> > $a + >>$b + $c<<
> >
> > vs.
> >
> > $a +<< ($b + $c)
>
> I have to agree with Larry here, the latter is much cleaner.
>
> I'm actually starting to like this proposal. I used to shiver at the
> implementation of the old way, where people used the operator to group
> arbitrary parts of the expression. I wouldn't even know how to parse
> that, much less interpret it when it's parsed.
>
> Now, we have a clear way to call a method on a list of values:
>
> @list ».method
>
> And a clear way to call a list of methods on a value:
>
> $value.« @methods
>
> It's turning out pretty nice.
I just realized a potential flaw here. Consider the code
$a >>= 1;
Will this right-shift the value of $a one bit and assign the result to $a
(the current meaning)? Or will it assign the value 1 to each element in the
array referenced by $a (as suggested by the new syntax). Both of these are
perfectly valid operations, and I don't think its acceptable to have the
same syntax mean both. I'm aware that using "»=" instead of ">>=" will
eliminate the inconsistency, but not everyone has easy access to Unicode
keyboards.
Joe Gottman
Thread Previous
|
Thread Next