请教 closure是什么意思？

Ray001

1. use File::Find;
   
2. 
   
3. my $callback;
   
4. {
   
5.   my $count = 0;
   
6.   $callback = sub { print ++$count, ": $File::Find::name\n" };
   
7. }
   
8. find($callback, '.');
   
9. 
   
10. 
    
11. 
    

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Here, we declare a variable to hold the callback. We cannot declare this variable within the naked block (the block following that is not part of a larger Perl syntax construct), or Perl will recycle it at the end of that block. Next, the lexical $count variable is initialized to 0. We then declare an anonymous subroutine and place its reference into $callback. This subroutine is a closure because it refers to the lexical $count variable.
Intermediate.Perl，第7.4节 ， closure没看懂啊！求各位指教。

MMMIX

Here, we declare a variable to hold the callback. We cannot declare this variable within the naked b ...
Ray001 发表于 2010-03-22 16:06

    perlref 中有讲，可以看看。

Ray001

http://baike.baidu.com/view/648413.htm
呵呵找了个中文版，谢谢版主。

churchmice

5.10中直接引入了state,这个和closure是一样的

1. 
   
2. sub {
   
3.     state $x =1;
   
4.     print $x++,"\n";
   
5. }
   

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xiaojao

Larry Wall把闭包描述成只是一个带有数据的匿名过程。

兰花仙子

我在这个帖子里有过解释：

http://bbs.chinaunix.net/viewthr ... p;extra=&page=2

xiaozhu8766

我也正在看~~~我的理解是相当于C++的local static吧~~