Well, you could but I don't know why you'd want to.
In the following script (using Benchmark) you'll see:
-
splice is relatively less efficient.
I also suspect it might have future maintainers scratching their heads wondering why it was used ("splice @array, 0, 1" has identical functionality to "shift @array" — it's just slower and requires more keystrokes to code).
-
shift is more efficient than splice.
-
My original map is faster than both of those;
it doesn't destroy the original array;
and it's a lot less coding.
#!/usr/bin/env perl
use strict;
use warnings;
use Benchmark qw{cmpthese};
cmpthese -1 => {
splice_unique => \&splice_unique,
shift_unique => \&shift_unique,
map_unique => \&map_unique,
};
sub splice_unique {
my @sorted = sort qw{q w e r t y q w e r t y};
my $last = '';
my @unique;
while (@sorted) {
my $element = splice @sorted, 0, 1;
if ($last ne $element) {
$last = $element;
push @unique, $element
}
}
}
sub shift_unique {
my @sorted = sort qw{q w e r t y q w e r t y};
my $last = '';
my @unique;
while (@sorted) {
my $element = shift @sorted;
if ($last ne $element) {
$last = $element;
push @unique, $element
}
}
}
sub map_unique {
my @sorted = sort qw{q w e r t y q w e r t y};
my $last = '';
my @unique = map { $last eq $_ ? () : ($last = $_) } @sorted;
}
Representative result:
Rate splice_unique shift_unique map_unique
splice_unique 93699/s -- -5% -20%
shift_unique 98642/s 5% -- -16%
map_unique 117028/s 25% 19% --