Method: Hash#subset

Defined in:
lib/core/facets/hash/subset.rb

#subset(*keys, &block) ⇒ Object

Take a subset of the hash, based on keys given or a block that evaluates to true for each hash key.

{'a'=>1, 'b'=>2}.subset('a')            #=> {'a'=>1}
{'a'=>1, 'b'=>2}.subset{|k| k == 'a'}   #=> {'a'=>1}

CREDIT: Alexey Petrushin



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# File 'lib/core/facets/hash/subset.rb', line 10

def subset(*keys, &block)
  h = {}

  if block
    raise ArgumentError, "subset arguments and block are exclusive parameters" unless keys.empty?
    each do |k, v|
      h[k] = v if block.call(k)
    end
  else
    each do |k, v|
      h[k] = v if keys.include?(k)
    end
  end

  return h
end