string-refine.rb

#!/usr/bin/env ruby

class Module
  def _refine(klass, &block)
    raise TypeError, "wrong argument type #{klass.class} (expected Class)" unless klass.is_a?(Class)

    const_set(klass.name, Class.new(klass, &block))
  end
end

module StringFormat
  #_refine String do
  # Equivalent to:
  class String < ::String
    # "{foo} {1} {0}".format('bar', 'baz', foo: 'foo') #=> "foo baz bar"
    def format(*args, **hsh)
      self.clone.gsub(/{(\S+)}/) do
        hsh[$1] || hsh[$1.to_sym] || args[$1.to_i]
      end
    end
  end
end

raise String.new("[1] String responds to format().") if String.new("").respond_to?(:format)

module InsertRandomlyGeneratedModuleNameHere
  include StringFormat

  raise String.new("[2] String does not respond to format().") unless String.new("").respond_to?(:format)

  puts String.new("{foo} {1} {0}").format('bar', 'baz', foo: 'foo') #=> "foo baz bar"
end

raise String.new("[3] String responds to format().") if String.new("").respond_to?(:format)