Module: GosuWrapper::Util

Included in:
GosuWrapper
Defined in:
lib/gosu_wrapper/util.rb

Instance Method Summary collapse

Instance Method Details

#method_missing_for(regex, type:, &definition_blk) ⇒ Object 



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# File 'lib/gosu_wrapper/util.rb', line 5

def method_missing_for(regex, type:, &definition_blk)
# Regex should include a match group
# type should be either :instance or :class
# Definition blk is run unless there's an existing method with the same name.
# if caller_blk is provided, it will be passed to definition_blk's invocation
#
# Example:
#
# class Animal
#   extend Util
#   attr_reader :noises
#   def initialize
#     @noises = { cat: "meow" }
#   end
#   method_missing_for /^(.+)_goes$/ do |match, arg|
#     puts @noises[match]
#   end
# end
# 
# Animal.new.cat_goes # => "meow"
#
# Through the use of an anonymous modules (adding method_missing to the
# inheritance chain vs overwriting it with define_method), this can be
# used multiple times.
#
  anon_module = Module.new do |mod|
    define_method(:method_missing) do |name, *args, **keywords, &caller_blk|
      match = name.to_s.scan(regex).flatten[0]
      if match
        if respond_to?(name)
          send(name, *args, &caller_blk)
        else
          if type == :instance
            instance_eval &(
              definition_blk.call(match, *args, **keywords, &caller_blk)
            )
          elsif type == :class
            singleton_class.class_exec &(
              definition_blk.call(match, *args, **keywords, &caller_blk)
            )
          end
        end
      else
        super(name, *args, **keywords, &caller_blk)
      end
    end
  end

  base = case type
  when :instance
    self
  when :class
    self.singleton_class
  end
  base.prepend anon_module

end