From: Srijayanth Sridhar <srijayanth@...>
Date: 2009-05-08T18:42:06+09:00
Subject: Re: Understanding { } and block_given

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This is definitely not a block_given thing.

block is coming through as a NilClass it seems.

puts block.class yields NilClass. The strange bit is that when I do it
outside of instance_eval with just a define_method under irb, it works as
expected. I am lost.

Anyone?

Jayanth

On Fri, May 8, 2009 at 11:19 AM, Srijayanth Sridhar <srijayanth@gmail.com>wrote:

> Hello,
>
> I have the following:
>
> class DSL
>   def DSL.load filename
>      dsl = new
>      dsl.instance_eval(File.read(filename))
>      dsl
>   end
>   def to sym,*args,&block
>      if block_given?
>         b=class << self;self;end
>         b.instance_eval {
>            define_method(sym,*args,&block)
>         }
>      end
>   end
>   def method_missing sym,*args
>      "#{sym}"
>   end
>   alias :say puts
> end
>
> foo=DSL.load("sample.dsl")
>
>
> sample.dsl:
>
> to smile do
>   say ":)"
> end
> to be_polite {
>   say "thank you"
> }
> smile
> be_polite
>
>
> The resulting output is:
>
> moonwolf@trantor:~/ruby/dsl/todo$ ./dsl.rb
> :)
> moonwolf@trantor:~/ruby/dsl/todo$
>
> be_polite and indeed, anything enclosded in {} doesn't seem to be eval-ed
> as
> blocks. Why is this?
>
> Jayanth
>

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