perl - 为什么 `sort List::Util::uniq(BAR, BAZ);` 与 `sort &List::Util::uniq(BAR, BAZ);` 不同

Question

我知道 & 会禁用原型(prototype)，但括号也不会这样做。这两个代码块有什么不同，顶部不能像底部一样运行是否有原因，

use List::Util;
use constant FOO => (1,2,3);
use constant BAR => (2,3,4,5,6);
use constant FOOBAR => sort List::Util::uniq(FOO, BAR);

use List::Util;
use constant FOO => (1,2,3);
use constant BAR => (2,3,4,5,6);
use constant FOOBAR => sort &List::Util::uniq(FOO, BAR);

Answer 1

sort很特别。

Warning: syntactical care is required when sorting the listreturned from a function. If you want to sort the list returned bythe function call "find_records(@key)", you can use:

           my @contact = sort { $a cmp $b } find_records @key;
           my @contact = sort +find_records(@key);
           my @contact = sort &find_records(@key);
           my @contact = sort(find_records(@key));

If instead you want to sort the array @key with the comparisonroutine "find_records()" then you can use:

           my @contact = sort { find_records() } @key;
           my @contact = sort find_records(@key);
           my @contact = sort(find_records @key);
           my @contact = sort(find_records (@key));