Class: MultiHash

Inherits:
Object
  • Object
show all
Defined in:
lib/multihash/multihash.rb

Overview

This class provides a very simple interface for a hash with multiple keys that reference the same value. This is convenient for lookup tables that have several mappings to a single value, without doing anything particularly gross with Array#include? lookups.

Instance Method Summary collapse

Constructor Details

#initialize(original_hash) ⇒ MultiHash

Initialize an immutable multihash with the provided hash as its source. For example, we might want to look up the nation which produces different types of cars:

MultiHash.new (
  %w{Honda Nissan} => :japan,
  %w{Ford Chrysler} => :us,
  'BMW' => :germany
)

a multihash, with arrays or single objects as keys.

Parameters:

  • original_hash (Hash<Array|Object, Object>) —

    the hash to convert into



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# File 'lib/multihash/multihash.rb', line 18

def initialize(original_hash)
  @_hash = Hash.new

  original_hash.each do |orig_key, value|
    key_array = orig_key.is_a?(Array) && orig_key || [orig_key]
    key_array.each { |k| @_hash[k] = value }
  end
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/multihash/multihash.rb', line 27

def [](key)
  @_hash[key]
end