From: tfdj <dario_insane@...>
Date: 2006-04-02T00:11:02+09:00
Subject: Eval needs explicit self for accessor methods?

hi all!

  i encountered a strange problem with eval. please see the following
test case:


require 'test/unit'

class TestContext

  def eval_in_context( ruby_code )
    instance_eval ruby_code
  end

  def toast
    @toast
  end

  def toast=( val )
    @toast = val
  end

end



class TestMetaEval < Test::Unit::TestCase

  def test_toast
    tc = TestContext.new
    tc.toast = 'yes'

    assert_equal 'yes', tc.toast
    assert_equal 'yes', tc.eval_in_context( "toast" )

    # These two lines - using explicit self - work as expected:
    assert_equal 'maybe', tc.eval_in_context( "self.toast = 'maybe'" )
    assert_equal 'maybe', tc.toast

    # What is happening here:
    assert_equal 'no', tc.eval_in_context( "toast = 'no'" )

    # Why does the next test fail?
    # What did the previous line set? A local variable?

    # tc.toast returns 'maybe' here instead of the expected 'no':
    assert_equal 'no', tc.toast
  end

end


  why is the 'toast=(val)' method not visible in eval unless i
explicitly use "self.toast = ..."?

  what is it i don't understand about ruby scoping? :/

any help really appreciated!

cheers,

daniel

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