From: Devin Mullins <twifkak@...>
Date: 2005-06-29T11:34:13+09:00
Subject: Re: yield does not take a block

Eric Mahurin wrote:

>Having the yield keyword does
>make it a little more difficult.
>  
>
Actually, it makes it a lot more difficult. Consider:

irb(main):039:0> def blah
irb(main):040:1> eval "yield", binding
irb(main):041:1> end
=> nil
irb(main):042:0> blah { puts 5 }
5
=> nil

In any case, I don't have a strong opinion on the "arity" of blocks. I 
*do* have a fairly strong opinion that consistency should be favored 
wherever possible, but nothing real to back it up, other than that (the 
lack of) it is what I dislike most about Java (primitives, null, 
Serializable, java.lang...), and it is what I like most about Ruby.

>As it stands now, this code block is
>actually statically typed to Proc and not just an object that
>responds to call and arity.  I would prefer it to be any old
>duck that can call and arity.
>  
>
Agreed. That code be done without changing any of the current syntax, too.

irb(main):047:0> blah(&proc{puts 5})
5
=> nil

irb(main):048:0> p = Object.new
=> #<Object:0x2b31990>
irb(main):049:0> class << p
irb(main):050:1> def call
irb(main):051:2> puts 5
irb(main):052:2> end
irb(main):053:1> end
=> nil
irb(main):054:0> blah(&p)
TypeError: wrong argument type Object (expected Proc)
        from (irb):54
        from :0

Boo. :(

Devin
But yay, Ruby, in general.

Also, yay for just having an irb session sitting around in my taskbar. 
Does that make me a packrat?