From: transfire@...
Date: 2006-06-06T06:12:57+09:00
Subject: Re: Hash to OpenStruct (#81)

This is new 'facets/core/hash/to_ostruct_recurse':

  require 'ostruct'
  require 'facets/core/ostruct/__update__'

  class Hash

    # Like to_ostruct but recusively objectifies all hash elements as
well.
    #
    #   o = { 'a' => { 'b' => 1 } }.to_ostruct_recurse
    #   o.a.b  #=> 1
    #
    # The +exclude+ parameter is used internally to prevent infinite
    # recursion and is not intended to be utilized by the end-user.
    # But for more advanced usage, if there is a particular subhash you
    # would like to prevent from being converted to an OpenStruct
    # then include it in the exclude hash referencing itself. Eg.
    #
    #     h = { 'a' => { 'b' => 1 } }
    #     o = h.to_ostruct_recurse( { h['a'] => h['a'] } )
    #     o.a['b']  #=> 1
    #

    def to_ostruct_recurse( exclude={} )
      return exclude[self] if exclude.key?( self )
      o = exclude[self] = OpenStruct.new
      h = self.dup
      each_pair do |k,v|
        h[k] = v.to_ostruct_recurse( exclude ) if v.respond_to?(
:to_ostruct_recurse )
      end
      o.__update__( h )
    end

  end

OpenStruct#__update__ is essentially:

  class OpenStruct
    def __update__( other )
      for k,v in hash
        @table[k.to_sym] = v
      end
      self
    end
  end

Any improvements greatly appreciated.

T.