[英]How do I use an array as an object attribute in Perl?
我需要一些关于Perl中数组的帮助
这是我的构造函数。
BuildPacket.pm
sub new {
my $class = shift;
my $Packet = {
_PacketName => shift,
_Platform => shift,
_Version => shift,
_IncludePath => [@_],
};
bless $Packet, $class;
return $Packet;
}
sub SetPacketName {
my ( $Packet, $PacketName ) = @_;
$Packet->{_PacketName} = $PacketName if defined($PacketName);
return $Packet->{_PacketName};
}
sub SetIncludePath {
my ( $Packet, @IncludePath ) = @_;
$Packet->{_IncludePath} = \@IncludePath;
}
sub GetPacketName {
my( $Packet ) = @_;
return $Packet->{_PacketName};
}
sub GetIncludePath {
my( $Packet ) = @_;
@{ $Packet->{_IncludePath} };
}
(代码已经根据'gbacon'的建议进行了修改,谢谢)
我以动态的方式将相对路径推入'includeobjects'数组。 正在从xml文件中读取include路径并将其推送到此数组中。
# PacketInput.pm
if($element eq 'Include')
{
while( my( $key, $value ) = each( %attrs ))
{
if($key eq 'Path')
push(@includeobjects, $value);
}
}
所以,includeobject将是这样的:
@includeobjects = (
"./input/myMockPacketName",
"./input/myPacket/my3/*.txt",
"./input/myPacket/in.html",
);
我正在使用此行来设置包含路径
$newPacket->SetIncludePath(@includeobjects);
同样在PacketInput.pm
,我有
sub CreateStringPath
{
my $packet = shift;
print "printing packet in CreateStringPath".$packet."\n";
my $append = "";
my @arr = @{$packet->GetIncludePath()};
foreach my $inc (@arr)
{
$append = $append + $inc;
print "print append :".$append."\n";
}
}
我有很多数据包,所以我循环遍历每个数据包
# PacketCreation.pl
my @packets = PacketInput::GetPackets();
foreach my $packet (PacketInput::GetPackets())
{
print "printing packet in loop packet".$packet."\n";
PacketInput::CreateStringPath($packet);
$packet->CreateTar($platform, $input);
$packet->GetValidateOutputFile($platform);
}
get和set方法适用于PacketName。 但由于IncludePath是一个数组,我无法让它工作,我的意思是相对路径没有打印。
如果启用strict pragma,则代码甚至无法编译:
Global symbol "@_IncludePath" requires explicit package name at Packet.pm line 15. Global symbol "@_IncludePath" requires explicit package name at Packet.pm line 29. Global symbol "@_IncludePath" requires explicit package name at Packet.pm line 30. Global symbol "@_IncludePath" requires explicit package name at Packet.pm line 40.
不要在密钥中使用@
unquoted,因为它会使解析器混淆。 我建议完全删除它们,以免混淆人类读者的代码。
您似乎想要将所有属性值从参数拉到构造函数,因此继续使用shift
剥离标量值,然后剩下的所有内容必须是包含路径。
我假设include路径的组件将是简单的标量而不是引用; 如果是后者,那么你会想要为安全做出深刻的副本。
sub new {
my $class = shift;
my $Packet = {
_PacketName => shift,
_Platform => shift,
_Version => shift,
_IncludePath => [ @_ ],
};
bless $Packet, $class;
}
请注意,由于Perl subs的语义,不需要将blessed对象存储在临时变量中,然后立即返回它:
如果未找到
return
值,并且最后一个语句是表达式,则返回其值。
以下方法也将使用此功能。
给定上面的构造函数, GetIncludePath
成为
sub GetIncludePath {
my( $Packet ) = @_;
my @path = @{ $Packet->{_IncludePath} };
wantarray ? @path : \@path;
}
这里有几件事情。 首先,请注意我们要小心返回包含路径的副本,而不是直接引用内部数组。 这样,用户可以修改从GetIncludePath
返回的值,而不必担心丢弃数据包的状态。
wantarray
运算符允许sub确定其调用的上下文并相应地做出响应。 在列表上下文中, GetIncludePath
将返回数组中的值列表。 否则,它返回对数组副本的引用。 这样,客户端代码可以像在中一样调用它
foreach my $path (@{ $packet->GetIncludePath }) { ... }
要么
foreach my $path ($packet->GetIncludePath) { ... }
SetIncludePath
是SetIncludePath
sub SetIncludePath {
my ( $Packet, @IncludePath ) = @_;
$Packet->{_IncludePath} = \@IncludePath;
}
请注意,您可以在构造函数中使用类似的代码,而不是一次使用shift
删除一个参数。
您可以使用上面定义的类,如
#! /usr/bin/perl
use strict;
use warnings;
use Packet;
sub print_packet {
my($p) = @_;
print $p->GetPacketName, "\n",
map(" - [$_]\n", $p->GetIncludePath),
"\n";
}
my $p = Packet->new("MyName", "platform", "v1.0", qw/ foo bar baz /);
print_packet $p;
my @includeobjects = (
"./input/myMockPacketName",
"./input/myPacket/my3/*.txt",
"./input/myPacket/in.html",
);
$p->SetIncludePath(@includeobjects);
print_packet $p;
print "In scalar context:\n";
foreach my $path (@{ $p->GetIncludePath }) {
print $path, "\n";
}
输出:
MyName - [foo] - [bar] - [baz] MyName - [./input/myMockPacketName] - [./input/myPacket/my3/*.txt] - [./input/myPacket/in.html] In scalar context: ./input/myMockPacketName ./input/myPacket/my3/*.txt ./input/myPacket/in.html
减少打字的另一种方法是使用Moose。
package Packet;
use Moose::Policy 'Moose::Policy::JavaAccessors';
use Moose;
has 'PacketName' => (
is => 'rw',
isa => 'Str',
required => 1,
);
has 'Platform' => (
is => 'rw',
isa => 'Str',
required => 1,
);
has 'Version' => (
is => 'rw',
isa => 'Int',
required => 1,
);
has 'IncludePath' => (
is => 'ro',
isa => 'ArrayRef[Str]',
default => sub {[]},
traits => [ 'Array' ],
handles => {
getIncludePath => 'elements',
getIncludePathMember => 'get',
setIncludePathMember => 'set',
},
);
__PACKAGE__->meta->make_immutable;
no Moose;
1;
查看Moose :: Manual :: Unsweetened ,了解Moose如何节省时间的另一个例子。
如果您坚持学习经典Perl OOP的愿望,请阅读以下perldoc文章: perlboot , perltoot , perlfreftut和perldsc 。
一本关于经典Perl OO的好书是Damian Conway的面向对象Perl 。 它将让您了解Perl对象的可能性。
一旦你理解了@ gbacon的答案 ,就可以使用Class :: Accessor :: Fast保存一些输入:
#!/usr/bin/perl
package My::Class;
use strict; use warnings;
use base 'Class::Accessor::Fast';
__PACKAGE__->follow_best_practice;
__PACKAGE__->mk_accessors( qw(
IncludePath
PacketName
Platform
Version
));
use overload '""' => 'to_string';
sub to_string {
my $self = shift;
sprintf(
"%s [ %s:%s ]: %s",
$self->get_PacketName,
$self->get_Platform,
$self->get_Version,
join(':', @{ $self->get_IncludePath })
);
}
my $obj = My::Class->new({
PacketName => 'dummy', Platform => 'Linux'
});
$obj->set_IncludePath([ qw( /home/include /opt/include )]);
$obj->set_Version( '1.05b' );
print "$obj\n";
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