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# ex:ts=8 sw=4:
# $OpenBSD: UList.pm,v 1.1 2014/04/16 10:31:27 zhuk Exp $
#
# Copyright (c) 2013 Vadim Zhukov <zhuk@openbsd.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
use strict;
use warnings;
use feature qw(say);
# Hash that preserves order of adding items and avoids duplicates.
# Also, some additional restrictions are applied to make sure
# the usage of this list is straightforward.
package LT::UList;
require Tie::Array;
our @ISA = qw(Tie::Array);
sub _translate_num_key($$;$) {
if ($_[1] < 0) {
$_[1] = @{$_[0]} - (-$_[1]);
die "invalid index" if $_[1] < 1;
} else {
$_[1] += 1;
}
die "invalid index" if $_[1] - int($_[2] // 0) >= @{$_[0]};
}
# Given we have successfully added N directories:
# self->[0] = { directory => 1 }
# self->[1 .. N] = directories in the order of addition, represented as 0..N-1
sub TIEARRAY {
my $class = shift;
my $self = bless [ {} ], $class;
$self->PUSH(@_);
return $self;
}
# Unfortunately, exists() checks for the value being integer even in the
# case we have EXISTS() outta there. So if you really need to check the
# presence of particular item, call the method below on the reference
# returned by tie() or tied() instead.
sub exists { return exists $_[0]->[0]->{$_[1]}; }
sub FETCHSIZE { return scalar(@{$_[0]}) - 1; }
# not needed
sub STORE { die "unimplemented and should not be used"; }
sub DELETE { die "unimplemented and should not be used"; }
sub EXTEND { }
sub FETCH
{
my ($self, $key) = (shift, shift);
# ignore?
die "undef given instead of directory or index" unless defined $key;
$self->_translate_num_key($key);
return $self->[$key];
}
sub STORESIZE
{
my ($self, $newsz) = (shift, shift() + 2);
my $sz = @$self;
if ($newsz > $sz) {
# XXX any better way to grow?
$self->[$newsz - 1] = undef;
} elsif ($newsz < $sz) {
$self->POP() for $newsz .. $sz - 1;
}
}
sub PUSH
{
my $self = shift;
for (@_) {
next if exists $self->[0]->{$_};
$self->[0]->{$_} = @$self;
push(@$self, $_);
}
}
sub POP
{
my $self = shift;
return undef if @$self < 2;
my $key = pop @$self;
delete $self->[0]->{$key};
return $key;
}
sub SHIFT
{
my $self = shift;
return undef if @$self < 2;
my $key = splice(@$self, 1, 1);
delete $self->[0]->{$key};
return $key;
}
sub UNSHIFT
{
my $self = shift;
$self->SPLICE(0, 0, @_);
}
sub SPLICE
{
my $self = shift;
my $offset = shift // 0;
$self->_translate_num_key($offset, 1);
my $maxrm = @$self - $offset;
my $length = shift;
if (defined $length) {
$length = $maxrm - (-$length) if $length < 0;
$length = $maxrm if $length > $maxrm;
} else {
$length = $maxrm;
}
# do not ever dream of adding items here
my @ret = splice(@$self, $offset, $length);
for (@ret) {
delete $self->[0]->{$_};
}
for ($offset .. scalar(@$self) - 1) {
$self->[0]->{$self->[$_]} -= $length;
}
return @ret unless scalar(@_);
if ($length == $maxrm) {
# simply add items to the end
$self->PUSH(@_);
return @ret;
}
my $newpos = $offset;
for (@_) {
my $index = $self->[0]->{$_};
if (defined $index) {
if ($index < $offset) {
# skip current item totally
continue;
} elsif ($index == $offset) {
# skip adding but act as if added
$self->[0]->{$_} += $newpos - $offset;
$newpos++;
next;
}
splice(@$self, $index, 1);
}
splice(@$self, $newpos, 0, $_);
$self->[0]->{$_} = $newpos++;
}
for ($newpos .. scalar(@$self) - 1) {
$self->[0]->{$self->[$_]} += $newpos - $offset;
}
return @ret;
}
=head1 test
package main;
my $r = ['/path0', '/path1'];
tie(@$r, 'LT::UList');
#push(@$r, '/path0');
#push(@$r, '/path1');
push(@$r, '/path2');
push(@$r, '/path3');
push(@$r, '/path4');
push(@$r, '/path3');
push(@$r, '/path1');
push(@$r, '/path5');
say "spliced: ".join(", ", splice(@$r, 2, 2, '/pathAdd1', '/pathAdd2', '/pathAdd1'));
#say "a: ".join(", ", @a);
say "r: ".join(", ", @$r);
#say "r2: ".join(", ", @$r2);
=cut
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