求讲解这个new函数是什么意思

snriyt

1. [code][code]package Mojo::Base;
   
2. 
   
3. use strict;
   
4. use warnings;
   
5. use utf8;
   
6. use feature ();
   
7. 
   
8. # No imports because we get subclassed, a lot!
   
9. use Carp ();
   
10. 
    
11. # Only Perl 5.14+ requires it on demand
    
12. use IO::Handle ();
    
13. 
    
14. sub import {
    
15.   my $class = shift;
    
16.   return unless my $flag = shift;
    
17.   no strict 'refs';
    
18. 
    
19.   # Base
    
20.   if ($flag eq '-base') { $flag = $class }
    
21. 
    
22.   # Strict
    
23.   elsif ($flag eq '-strict') { $flag = undef }
    
24. 
    
25.   # Module
    
26.   elsif ((my $file = $flag) && !$flag->can('new')) {
    
27.     $file =~ s!::|'!/!g;
    
28.     require "$file.pm";
    
29.   }
    
30. 
    
31.   # ISA
    
32.   if ($flag) {
    
33.     my $caller = caller;
    
34.     push @{"${caller}::ISA"}, $flag;
    
35.     *{"${caller}::has"} = sub { attr($caller, @_) };
    
36.   }
    
37. 
    
38.   # Mojo modules are strict!
    
39.   strict->import;
    
40.   warnings->import;
    
41.   utf8->import;
    
42.   feature->import(':5.10');
    
43. }
    
44. 
    
45. sub new {
    
46.   my $class = shift;
    
47.   bless @_ ? @_ > 1 ? {@_} : {%{$_[0]}} : {}, ref $class || $class;
    
48. }

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[/code][/code]

fender0107401

哎呦，我去，这家伙写的真好啊。

stanley_tam

成心不让人看懂哈。貌似是这样的{:3_204:}：

1. sub new {
   
2.     my $class = shift;
   
3.     my $self = +{};
   
4. 
   
5.     $class = ref $class || $class;
   
6. 
   
7.     if (@_) {
   
8.         if (@_> 1) {
   
9.             $self = {@_};
   
10.         }
    
11.         else {
    
12.             # { %{$_[0]} } is equivalent to $_[0] but raise error when $_[0] is not hash reference
    
13.             $self = $_[0];  
    
14.         }
    
15.     }
    
16. 
    
17.     bless $self, $class;
    
18. }

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