比较和编辑哈希中的基础结构 [英] Compare and edit underlying structure in hash

问题描述

我有一个结构复杂的哈希，我想执行搜索和替换.第一个哈希如下所示:

I have a hash of complex structure and I want to perform a search and replace. The first hash is like the following:

$VAR1 = {
  abc => { 123 => ["xx", "yy", "zy"], 456 => ["ab", "cd", "ef"] },
  def => { 659 => ["wx", "yg", "kl"], 456 => ["as", "sd", "df"] },
  mno => { 987 => ["lk", "dm", "sd"] },
}

，我想迭代搜索所有'123'/'456'元素，如果找到匹配项，则需要对子层(即['ab','cd','ef']和['as','sd','df'])进行比较，在这种情况下，仅保留带有['ab'，'cd'，'ef']的那个.因此输出如下:

and I want to iteratively search for all '123'/'456' elements, and if a match is found, I need to do a comparison of the sublayer, i.e. of ['ab','cd','ef'] and ['as','sd','df'] and in this case, keep only the one with ['ab','cd','ef']. So the output will be as follows:

$VAR1 = {
  abc => { 123 => ["xx", "yy", "zy"], 456 => ["ab", "cd", "ef"] },
  def => { 659 => ["wx", "yg", "kl"] },
  mno => { 987 => ["lk", "dm", "sd"] },
}

因此，删除操作基于子结构，而不是索引.怎么做到呢?感谢您的帮助！

So the deletion is based on the substructure, and not index. How can it be done? Thanks for the help!!

让我们假设我将声明要保留的值，即我将保留456 => [" ab，" cd，" ef]基于预先声明的值[[ab"，"cd ，" ef]并删除其他任何456实例.搜索必须针对每个键.因此，代码将遍历哈希，首先取123 => ["，" yy，" zy]，然后将其与哈希的其余部分中的键进行比较，如果找不到匹配项，则不执行任何操作.如果找到匹配项，例如在456 => [" ab，" cd，" ef]的情况下，它将比较两者，并且正如我已经说过的那样，在匹配项中，带有["的匹配项ab，" cd，" ef]将被保留，它将保留456 => [" ab，" cd，" ef]并在哈希中其他任何地方丢弃456的任何其他实例，即它将在这种情况下，删除456 => ["as"，"sd"，"df"].

Lets assume that I will declare the values to be kept, i.e. I will keep 456 => ["ab", "cd", "ef"] based on a pre-declared value of ["ab", "cd", "ef"] and delete any other instance of 456 anywhere else. The search has to be for every key. so the code will go through the hash, first taking 123 => ["xx", "yy", "zy"] and compare it against the keys throughout the rest of the hash, if no match is found, do nothing. If a match is found, like in the case of 456 => ["ab", "cd", "ef"], it will compare the two, and as I have said that in case of a match the one with ["ab", "cd", "ef"] would be kept, it will keep 456 => ["ab", "cd", "ef"] and discard any other instances of 456 anywhere else in the hash, i.e. it will delete 456 => ["as", "sd", "df"] in this case.

推荐答案

以下是使用智能匹配运算符执行数组比较的解决方案:

Here is a solution that uses the smart match operator to perform the array comparison:

更新:正如Borodin所指出的，我的原始代码是错误的.这是固定版本.

Update: as Borodin pointed out, my original code was wrong. This is the fixed version.

更新2:对其进行了更改，以根据哈希结构选择要保留的值.

Update 2: Changed it to choose the values to keep based on a hash structure.

my $VAR1 = {
  abc => { 123 => ["xx", "yy", "zy"], 456 => ["ab", "cd", "ef"] },
  def => { 659 => ["wx", "yg", "kl"], 456 => ["as", "sd", "df"] },
  mno => { 987 => ["lk", "dm", "sd"] },
};

my %keep_values = (
    '456' => ['ab','cd','ef']
);

foreach my $outer_key (keys %$VAR1)
{
    foreach my $keepers (keys %keep_values)
    {
        if (exists $VAR1->{$outer_key}{$keepers} and 
            #use the smart match operator to compare arrays.
            !(@{$VAR1->{$outer_key}{$keepers}} ~~ @{$keep_values{$keepers}}))
        {
            delete $VAR1->{$outer_key}{$keepers};
        }
    }   
}

有关智能匹配运算符的更多信息，请参见 perlop .

For more on the smart match operator, see perlop.

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