perl – 使用内联包继承常量

好.我在尝试继承任何子类的父类中设置的常量时遇到问题.

#!/usr/bin/perl
use Strict;
use warnings;

package Car;
use Exporter qw( import );
our @EXPORT_OK = ( 'WHEELS','WINGS' );

use constant WHEELS => 4;
use constant WINGS  => 0;

sub new {
    my ( $class,%args ) = @_;
    my $self = {
        doors  => $args{doors},colour => $args{Colour},wheels => WHEELS,wings  => WINGS,};
    bless $self,$class;
    return $self;
}

package Car::Sports;
use base qw( Car );

sub new {
    my ( $class,ENGIne => $args{ENGInE},$class;
    return $self;
}

package main;
my $obj = Car->new( doors => 4,colour => "red" );
print Dumper $obj;

my $obj2 = Car::Sports->new( doors => 5,ENGIne => "V8" );

print Dumper $obj2;
__END__

错误是：

Bareword "WHEELS" not allowed while "Strict subs" in use at ./t.pl line 30.
Bareword "WINGS" not allowed while "Strict subs" in use at ./t.pl line 30.
Execution of ./t.pl aborted due to compilation errors.

现在,我没有做过一些研究而没有来这里发帖.我知道一个选择是在Car :: Sports中使用Car qw(WHEELS WINGS).但是,如果我这样做,我会收到以下错误,因为这些类都在同一个文件中内联：

Can't locate Car.pm in @INC

出于各种原因,我需要将我的包保存在一个文件中.有没有解决的办法？由于常量基本上只是subs,为什么我必须导入它们,而对于普通方法则不一样？

最后,我也知道我可以这样做：

package Car::Sports;
use base qw( Car );

sub new {
    my ( $class,wheels => Car::WHEELS,wings  => Car::WINGS,$class;
    return $self;
}

它很好……但我有许多类,并希望使常量的继承更通用,必须明确地命名父类(有时它不仅仅是父类,而是祖父母).

非常感谢任何指针！

干杯

package Car::Sports;
use base qw( Car );
Car->import(qw(WHEELS WINGS));

...
wheels => &WHEELS,wings  => &WINGS,...

package Car;
our @EXPORT_OK;
BEGIN {@EXPORT_OK = qw(WHEELS WINGS)} # set at compile not run time
...

package Car::Sports;
use base qw(Car);
BEGIN {Car->import('WHEELS','WINGS')} # import before c'tor is parsed

use Car qw(WHEELS WINGS);