From: Robert Klemme <shortcutter@...>
Date: 2010-08-31T21:17:26+09:00
Subject: Re: XSLT-like search in a Ruby Hash

2010/8/31 Pito Salas <rps@salas.com>:
> I have a need for some relatively fancy searching in a hash, and I am
> wondering if there's anything that does some kind of pattern matching on
> Hash contents.
>
> Specifically here's an example of what I would like to be able to write:
> http://www.pastie.org/1127920
>
> Yes, I can write the iterators, collects, merges and what else, but
> nicer would be some kind of structured query syntax. Any ideas?

For the simple case one could do

class Hash
  def nested_value? *keys, val
    val.eql?( keys.inject(self) {|h,k| h.fetch(k) { return false } } )
rescue return false
  end

  def nested_key? *keys
    keys.inject(self) {|h,k| h.fetch(k) { return false } } rescue return false
    true
  end
end

Note, you need 1.9* for this - otherwise you need to manually
distribute arguments.

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
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