I've done a fair amount of searching on google, perlmonks, and cpan for this but have not turned up much, except Data::DRef and Data::Walker. Data::Walker provides a file-system-ish interface command line interfce for manual examination of data structures, but does not provide methods for searching the structures. Data::DRef does not appear to have "search" methods to locate keys recursively, but I will continue look more closely at it.

I have a nested data structure (hash at the top level, then mixture of hashes and arrays at lower levels, arbitrarily deep) that is read from a config file (Config::General).

I need a way to recursively search this data structure for particular hash keys, so that I can alter the data associated with them. For example, certain entries should always have a reference to an anonymous array, so I need to recursively search for a particular key, and wherever found, wrap it's value in an anonymous array if it is not already an array.

So, for example, given: 

{
  a => {
    b => 3,
  }
  b => 123,
  c => {
    b => [
      123,
      456,
      789,
    ],
  },
  d => [
    b => 456,
  ],
}

[download]
I need something that can find all occurrences of 'b' in this data structure, so that I can examine them and change them all to array references like this: 
{
  a => {
    b => [
      3,
    ]
  }
  b => [
    123,
  ],
  c => {
    b => [
      123,
      456,
      789,
    ],
  },
  d => [
    b => [
      456,
    ],
  ],
}

[download]

Similar functionality to what I need exists in File::Find, File::Find::Rule, HTML::TreeBuilder (especially it's look_down method), but these all target either filesystem or file traversal rather than perl data structure traversal.

In the interest of avoiding reinventing a wheel that I'm sure exists somewhere, but I've been unable to find, has anyone found a CPAN module to do this sort of thing?

In reply to Recursively search nested hash/array structures by mp

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