Port of clojure.walk to Ruby

walk.rb

module Walk

  refine Array do
    def walk(inner_f, outer_f)
      outer_f.(self.map(&inner_f))
    end
  end

  refine Hash do
    def walk(inner_f, outer_f)
      outer_f.(self.map { |e| e.map(&inner_f) }.to_h)
    end
  end

  refine Object do
    def walk(_inner_f, outer_f)
      outer_f.(self)
    end
  end

  using self

  def self.walk(inner_f, outer_f, object)
    object.walk(inner_f, outer_f)
  end

  def self._postwalk(f, object)
    g = self.method(:_postwalk).curry.(f)
    walk(g, f, object)
  end

  def self.postwalk(object, &block)
    _postwalk(block, object)
  end

  def self._prewalk(f, object)
    g = self.method(:_prewalk).curry.(f)
    walk(g, :itself.to_proc, f.(object))
  end

  def self.prewalk(object, &block)
    _prewalk(block, object)
  end

end

data = {
  foo: {
    foo: [
      { foo: "bar" },
      { foo: "baz" }
    ]
  }
}


Walk.prewalk(data) {|x| puts x.inspect ; x }
# {:foo=>{:foo=>[{:foo=>"bar"}, {:foo=>"baz"}]}}
# :foo
# {:foo=>[{:foo=>"bar"}, {:foo=>"baz"}]}
# :foo
# [{:foo=>"bar"}, {:foo=>"baz"}]
# {:foo=>"bar"}
# :foo
# "bar"
# {:foo=>"baz"}
# :foo
# "baz"
# => {:foo=>{:foo=>[{:foo=>"bar"}, {:foo=>"baz"}]}}


Walk.postwalk(data) {|x| puts x.inspect ; x }
# :foo
# :foo
# :foo
# "bar"
# {:foo=>"bar"}
# :foo
# "baz"
# {:foo=>"baz"}
# [{:foo=>"bar"}, {:foo=>"baz"}]
# {:foo=>[{:foo=>"bar"}, {:foo=>"baz"}]}
# {:foo=>{:foo=>[{:foo=>"bar"}, {:foo=>"baz"}]}}
# => {:foo=>{:foo=>[{:foo=>"bar"}, {:foo=>"baz"}]}}