Class: Hash

Inherits:
Object show all
Defined in:
lib/cnc/core_ext/hash.rb

Instance Method Summary collapse

Instance Method Details

#extract_if! ⇒ Object

Removes and returns a hash containing the key/value pairs for which the block returns a true value given the key.

hash = {:a => 1, "b" => 2, :c => 3}
hash.extract_if! { _1.is_a? Symbol } #=> {a: 1, c: 3}
hash                                 #=> {"b" => 2 }


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# File 'lib/cnc/core_ext/hash.rb', line 10

def extract_if!
  each_with_object(self.class.new) do |(key, value), result|
    result[key] = delete(key) if yield(key, value)
  end
end

#transform ⇒ Object

Returns a new hash with all values at the given keys converted using the given block.

hash = {a: 1, b: 2, c: 3}
hash.transform(:a, :b, &:succ) #=> {a: 2, b: 3, c: 3}


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# File 'lib/cnc/core_ext/hash.rb', line 34

def transform(...) = dup.transform!(...)

#transform!(*keys) ⇒ Object

Destructively converts all values at the given keys using the given block.

hash = {a: 1, b: 2, c: 3}
hash.transform!(:c, &:succ)
hash #=> {a: 1, b: 2, c: 4}


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# File 'lib/cnc/core_ext/hash.rb', line 22

def transform!(*keys)
  keys.each do |k|
    self[k] = yield self[k] if key?(k)
  end
  self
end