Contents

# frozen_string_literal: true

class Hash
  # Returns a new hash with +self+ and +other_hash+ merged recursively.
  #
  #   h1 = { a: true, b: { c: [1, 2, 3] } }
  #   h2 = { a: false, b: { x: [3, 4, 5] } }
  #
  #   h1.deep_merge(h2) # => { a: false, b: { c: [1, 2, 3], x: [3, 4, 5] } }
  #
  # Like with Hash#merge in the standard library, a block can be provided
  # to merge values:
  #
  #   h1 = { a: 100, b: 200, c: { c1: 100 } }
  #   h2 = { b: 250, c: { c1: 200 } }
  #   h1.deep_merge(h2) { |key, this_val, other_val| this_val + other_val }
  #   # => { a: 100, b: 450, c: { c1: 300 } }
  def deep_merge(other_hash, &block)
    dup.deep_merge!(other_hash, &block)
  end

  # Same as +deep_merge+, but modifies +self+.
  def deep_merge!(other_hash, &block)
    merge!(other_hash) do |key, this_val, other_val|
      if this_val.is_a?(Hash) && other_val.is_a?(Hash)
        this_val.deep_merge(other_val, &block)
      elsif block_given?
        block.call(key, this_val, other_val)
      else
        other_val
      end
    end
  end

  # Merges the caller into +other_hash+. For example,
  #
  #   options = options.reverse_merge(size: 25, velocity: 10)
  #
  # is equivalent to
  #
  #   options = { size: 25, velocity: 10 }.merge(options)
  #
  # This is particularly useful for initializing an options hash
  # with default values.
  def reverse_merge(other_hash)
    other_hash.merge(self)
  end
  alias_method :with_defaults, :reverse_merge

  # Destructive +reverse_merge+.
  def reverse_merge!(other_hash)
    replace(reverse_merge(other_hash))
  end
  alias_method :reverse_update, :reverse_merge!
  alias_method :with_defaults!, :reverse_merge!
end

Version data entries

4 entries across 4 versions & 1 rubygems

Version	Path
simple_ext-0.1.3	lib/simple_ext/hash/merge.rb
simple_ext-0.1.2	lib/simple_ext/hash/merge.rb
simple_ext-0.1.1	lib/simple_ext/hash/merge.rb
simple_ext-0.1.0	lib/simple_ext/hash/merge.rb