adjam · September 25, 2018 14:58
diff --git a/hashutil.rb b/hashutil.rb
 # refinement for Hash class that allows declarative remapping functions
 #
 # #remap(mapping)
 # and
 # #remap!(mapping)
 # methods.
 # The `mapping` hash maps key names in the original hash to their
 # names in the resulting hash, e.g.
 # `{ foo: 'bar' }.remap({foo: :fu}) => `{ fu: 'bar' }`
 # There are two special values that can be used in a mapping:
 #   `:__delete__` means that the key will be deleted, and
 #   if the value responds to `#call`, it will be invoked with two arguments:
 #   the key and value from the original hash, and it is expected to return
 #   an array of length 2, where the first element is the new key, and i
 #   the second  # element is the new value.
 #
 #   Example:
 #
 #   convert = { foo: 'bar'
 #               bar: ->(k, v) { [k.upcase, "#{k}_{v}" }
 #             }
 #
 #   { foo: :baz,
 #     bar: 'hey' }.remap(convert)
 #
 #     =>
 #     { baz: 'bar', BAR: "bar_hey" }
 #
 # The #remap and #remap! functions are identical except the latter
 # modifies the original hash in-place.
 #
 # To use this within a class or module, put
 # `using HashUtil` below the definition of your class or module.
 module HashUtil

    def self.rename_hash(h, names)
      names.each do |k, v|
        next unless h.key?(k)
        if v == :__delete__
          h.delete(k)
        else
          if v.respond_to?(:call)
            r = v.call(k, h.delete(k))
            h[r[0]] = r[1]
          else
            h[v] = h.delete(k)
          end
        end
      end
      h
    end

    refine Hash do
      def remap(names)
        copy = Marshal.load(Marshal.dump(self))
        HashUtil.rename_hash(copy, names)
      end

      def remap!(names)
        HashUtil.rename_hash(self, names)
      end
    end
 end
	# refinement for Hash class that allows declarative remapping functions
	#
	# #remap(mapping)
	# and
	# #remap!(mapping)
	# methods.
	# The `mapping` hash maps key names in the original hash to their
	# names in the resulting hash, e.g.
	# `{ foo: 'bar' }.remap({foo: :fu}) => `{ fu: 'bar' }`
	# There are two special values that can be used in a mapping:
	# `:__delete__` means that the key will be deleted, and
	# if the value responds to `#call`, it will be invoked with two arguments:
	# the key and value from the original hash, and it is expected to return
	# an array of length 2, where the first element is the new key, and i
	# the second # element is the new value.
	#
	# Example:
	#
	# convert = { foo: 'bar'
	# bar: ->(k, v) { [k.upcase, "#{k}_{v}" }
	# }
	#
	# { foo: :baz,
	# bar: 'hey' }.remap(convert)
	#
	# =>
	# { baz: 'bar', BAR: "bar_hey" }
	#
	# The #remap and #remap! functions are identical except the latter
	# modifies the original hash in-place.
	#
	# To use this within a class or module, put
	# `using HashUtil` below the definition of your class or module.
	module HashUtil

	def self.rename_hash(h, names)
	names.each do \|k, v\|
	next unless h.key?(k)
	if v == :__delete__
	h.delete(k)
	else
	if v.respond_to?(:call)
	r = v.call(k, h.delete(k))
	h[r[0]] = r[1]
	else
	h[v] = h.delete(k)
	end
	end
	end
	h
	end

	refine Hash do
	def remap(names)
	copy = Marshal.load(Marshal.dump(self))
	HashUtil.rename_hash(copy, names)
	end

	def remap!(names)
	HashUtil.rename_hash(self, names)
	end
	end
	end