From: Robert Klemme <shortcutter@...>
Date: 2007-11-20T21:45:59+09:00
Subject: Re: using lambda, binding happens immediately?

2007/11/19, Sam Larbi <slarbi@gmail.com>:
>  I have this code:
>
>
> require 'test/unit'
> require 'leapyear'
> class LeapYearTest < Test::Unit::TestCase
>    def setup
>      @ly = LeapYear.new
>    end
>    def LeapYearTest.generate_tests
>      filename = "testdata.dat"
>      file = File.new(filename, "r")
>      file.each_line do |line|
>       year, is_leap = line.split;
>       code = lambda { assert_equal(is_leap.downcase=="true", @ly.isleap?(
> year.to_i)) }
>       define_method("test_isleap_" + year, code)
>      end
>      file.close
>    end
> end
>
>
> What I want to know is why when I use define_method("name") {block;} instead
> of define_method("name", lambda{block}) the binding seems to happen later
> (after the each_line loop)?
>
> Is there a reason behind that?

I'm not sure I understand you but why don't you just do

define_method("test_isleap_" + year) do
  assert_equal(is_leap.downcase=="true", @ly.isleap?(year.to_i))
end

Btw, I'd also use the block form of File.open because it is more
robust than the idiom you are using.

Kind regards

robert

-- 
use.inject do |as, often| as.you_can - without end