James Mastros wrote:
Juerd wrote:
Just typing "my " before the first use of a variable isn't hard, and it
makes things much clearer for both the programmer and the machine.
Does this imply that it's now possible to type C,
and declare @foo? In the current perl, this doesn't work -- it's a
syntax error. It'd certainly make many constructs easier.
I see why that's an error. It can be very confusing In literal
fashion you are attempting to make the 24th element of @foo lexical, and
having some elements of @foo have different scope from the rest is a bad
idea.
However, I have also been bitten by that rather frequently, though with
a different construct. Typically it's with hash slices:
my @[EMAIL PROTECTED] = @[EMAIL PROTECTED]; # ERROR!
my %newhash;
@[EMAIL PROTECTED] = @[EMAIL PROTECTED]; # Okay, but not as convienent.
This was part of the reason I spawned this thread. But it was also due
to being in the middle of trying to write some decent quality code under
a heavy time pressure, and noticed that >50% of my lines had a 'my' on
them. It's typically not that high of a percentage, but when you are
creating lots of small utility routines, declaring all your lexicals can
be a significant part of the task. I added to this the observation that
lexical variables are significantly more common than non-lexicals, and
thought out loud as to why I was doing more work for the common case
than the uncommon case, in a language that generally doesn't have that
problem.
One of the other reasons in favor of the idea was aesthetic.
# stuff which declares $x, $z, and $q
$x = 4;
my $y = 7;
$z = 12;
my $r = 4543;
$q = 121;
compared to:
# stuff which declares $x, $z, and $q
$x = 4;
$y = 7;
$z = 12;
$r = 4543;
$q = 121;
With a fixed width font, like all code editors use, all the =' like up,
and I can quickly scan the var names to get to the one I want to change
at that moment. Yes, I could have added a 'my ($y, $r);' to the front of
the list, but that's adding another statement to the mix, same as the
hash slice above, adding considerably more weight to 'my' than just
three keystrokes (m - y - space).
However, given the strong opposition (with merits) to this in other
responses, I am willing to live with it the P5 way. Just seemed like
autolexicals was rather DWIMish.
Another facet of this discussion comes into account when also specifying
type.
from S9:
my bit @bits;
my int @ints;
my num @nums;
my int4 @nybbles;
my str @buffers;
my ref[Array] @ragged2d;
my complex128 @longdoublecomplex;
Wouldn't this be much better as:
bit @bits;
int @ints;
num @nums;
int4 @nybbles;
str @buffers;
ref[Array] @ragged2d;
complex128 @longdoublecomplex;
Given that most of the stated reservations had to deal with explicit
declaration better defining scope, what is wrong with drooping the my in
this case?
-- Rod Adams
