Contents

require 'facets/core/proc/bind'

module Kernel

  # Like instace_eval but allows parameters to be passed.

  unless defined?(instance_exec) # 1.9
    def instance_exec(*arguments, &block)
      block.bind(self)[*arguments]
    end
  end

end


=begin test

  require 'test/unit'

  class TestInstanceEvalWithArgs < Test::Unit::TestCase

    class Dummy
      def f
        :dummy_value
      end
    end

    def test_instance_exec
      # Create a block that returns the value of an argument
      # and a value of a method call to +self+.
      block = lambda { |a| [a, f] }
      assert_equal [:arg_value, :dummy_value],
        Dummy.new.instance_exec(:arg_value, &block)
    end

    def test_instance_exec_with_frozen_obj
      block = lambda { |a| [a, f] }
      obj = Dummy.new
      obj.freeze
      assert_equal [:arg_value, :dummy_value], obj.instance_exec(:arg_value, &block)
    end

    def test_instance_exec_nested
      i = 0
      obj = Dummy.new
      block = lambda do |arg|
        [arg] + instance_exec(1){|a| [f, a] }
      end
      assert_equal([:arg_value, :dummy_value, 1], obj.instance_exec(:arg_value, &block))
    end

    def test_instance_exec_with_immediate_value
      obj = 1
      block = lambda { |a| [a,self] }
      assert_equal(["A", 1], obj.instance_exec("A", &block))
    end

  end

=end

Version data entries

6 entries across 6 versions & 1 rubygems

Version	Path
facets-1.8.0	lib/facets/core/kernel/instance_exec.rb
facets-1.8.20	lib/facets/core/kernel/instance_exec.rb
facets-1.8.49	lib/facets/core/kernel/instance_exec.rb
facets-1.8.51	lib/facets/core/kernel/instance_exec.rb
facets-1.8.54	lib/facets/core/kernel/instance_exec.rb
facets-1.8.8	lib/facets/core/kernel/instance_exec.rb