From: Logan Capaldo <logancapaldo@...>
Date: 2007-09-09T12:39:20+09:00
Subject: Re: Bug in lambda?

On 9/8/07, kevin cline <kevin.cline@gmail.com> wrote:
> This looks like a pretty serious bug.  It seems that lambda-
> expressions are not properly localizing their formal arguments:
>
> bash-3.2$ ruby --version
> ruby 1.8.6 (2007-03-13 patchlevel 0) [i386-mswin32]
>
> bash-3.2$ cat lambda-bug.rb
> a = 0
> f = lambda { |a| a }
> puts "a = #{a}"
> puts "f.call(1) => #{f.call(1)}"
> puts "now a = #{a}"
>
> bash-3.2$ ruby lambda-bug.rb
> a = 0
> f.call(1) => 1
> now a = 1

Not a bug, it's a "feature". I don't like it either.

foo = lambda { |$this_works_too| }

foo.call(2)

p $this_works_too

class SoDoesThis
  attr_reader :foo
  def setter
     lambda { |@foo| }
  end
end

bar = SoDoesThis.new
bar.setter["this is sparta"]
p bar.foo