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如何在Perl中找出散列引用的位置?

hashmap perl

TheAdam122 · 技术社区 · 7 年前

我有一个脚本,它调用一个函数,通过将散列转换为引用递归地遍历散列,并且总是向引用添加下一个键。我想知道是否可以找到哈希引用指向的地方。这不是我的脚本,只是一个例子。

#!/usr/bin/perl -w

use strict;
use Data::Dumper;

my %hoh = (
    flintstones => {
        husband   => "fred",
        pal       => "barney",
    },
    jetsons => {
        husband   => "george",
        wife      => "jane",
        "his boy" => "elroy",
    },
    simpsons => {
        husband   => "homer",
        wife      => "marge",
        kid       => "bart",
    },
);

print Dumper \%hoh;

#my hash has way more levels and not all levels have the same depth
#my scrypt does what is in the next 3 lines, just through more levels

my $hoh_ref=\%hoh;
$hoh_ref=$hoh_ref->{flintstones};
$hoh_ref=$hoh_ref->{husband};

#it would be nice to know where a hash reference points, like the following example:
#sub findkeys{???}
#findkeys($hoh_ref);
#should return '$hoh{flintstones}{husband}' the syntax can be different

print "$hoh_ref\n";
print "$hoh{flintstones}{husband}\n";     #same as last line, just to demonstrate what it looks like using keys

我知道引用指向内存中的一个位置,所以如果散列引用只指向数据的位置,而不存储原始散列中所需的键,则不可能。我不想循环遍历原始散列并找到值所在的位置,关键是,如果有一种简单的方法可以做到这一点的话。如果没有,我可以跟踪键,哈希引用指向的地方,我只是好奇是否可以跳过它。

1 回复 | 直到 7 年前

-1

ikegami Gilles Quénot 7 年前

如何在Perl中找出散列引用的位置?

$hoh_ref 不是哈希引用(或任何类型的引用)。

my $hoh_ref = \%hoh;
$hoh_ref = $hoh_ref->{flintstones};
$hoh_ref = $hoh_ref->{husband};

与相同

my $hoh_ref = "fred";

也就是说它创建了标量 $HOH参考 并将其值设置为字符串 fred . 在这两种情况下,两者之间绝对没有关联(名称错误) $HOH参考 和 %hoh 但是,hoh的一个值恰好等于 $HOH参考 .

+- %hoh -----------------------+           +- Anon hash ------------------+
|               +-----------+  |     +---->|               +-----------+  |
|  flintstones: | Ref      ----------+     |  husband:     | fred      |  |
|               +-----------+  |           |               +-----------+  |
|  jetsons:     | Ref      ------------+   |  pal:         | barney    |  |
|               +-----------+  |       |   |               +-----------+  |
|  simpsons:    | Ref      --------+   |   +------------------------------+
|               +-----------+  |   |   |
+------------------------------+   |   |   +- Anon hash ------------------+
                                   |   +-->|               +-----------+  |
+- $hoh_ref -------------------+   |       |  husband:     | george    |  |
| fred                         |   |       |               +-----------+  |
+------------------------------+   |       |  wife:        | jane      |  |
                                   |       |               +-----------+  |
                                   |       |  his boy:     | elroy     |  |
                                   |       |               +-----------+  |
                                   |       +------------------------------+
                                   |
                                   |       +- Anon hash ------------------+
                                   +------>|               +-----------+  |
                                           |  husband:     | homer     |  |
                                           |               +-----------+  |
                                           |  wife:        | marge     |  |
                                           |               +-----------+  |
                                           |  kid:         | bart      |  |
                                           |               +-----------+  |
                                           +------------------------------+

所以,充其量,您可以迭代 %HOH 查找等于 $HOH参考 .

我不想循环遍历原始哈希并找到值的位置

太糟糕了。