From: Bob Hutchison <hutch@...>
Date: 2005-10-19T00:29:18+09:00
Subject: Re: Instance and class variable assignment


On Oct 18, 2005, at 10:03 AM, Christophe Grandsire wrote:

> Selon Daniel Schierbeck <daniel.schierbeck@gmail.com>:
>
>
>>
>> Can someone explain to me why this shouldn't be implemented in Ruby:
>>
>>    def foo(@a, @b = "foo", @@c = "bar")
>>      # do something
>>    end
>>
>>
>
> My eyes!!! >*_*<
>

And what are the binding rules?

def foo(@a = 1, @@b = @a)

is equivalent to what? Common Lisp has two binding rules that  
generally used, e.g. let and let*. These would give you:

def foo(a, b)
   old_a = @a
   @a = a
   @@b = old_a
end

and

def foo(x, a, b)
   @a = a
   @@b = @a
end

You need both in CL.

Cheers,
Bob

----
Bob Hutchison          -- blogs at <http://www.recursive.ca/hutch/>
Recursive Design Inc.  -- <http://www.recursive.ca/>
Raconteur              -- <http://www.raconteur.info/>