Re: lambda, ->, haskell, and so on

Hi-

Yukihiro Matsumoto <[e-mail]> wrote on 05/19/2008 10:23:29 AM:
> Hi,
> 
> In message "Re: lambda, ->, haskell, and so on"
>     on Tue, 20 May 2008 01:49:04 +0900, [e-mail].
> com writes:
> 
> |Second, there are a couple alternatives that we could use, leveraging 
> |existing Ruby syntax: 
> |
> | http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/16662
> | http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/16616
> 
> So, you prefer lambda(x) {...} or x => {...} over ->(x){...}, right?
> The latter (=>) conflicts with other part of Ruby syntax, namely hash
> literals, besides it complicates the language.
> 
> I am not fond of "lambda" being keyword, because
> 
>   * it changes meaning of the valid syntax ("lambda(a){p a}" is valid
>     in 1.8 with different semantics).
>   * it's long (6 letters).  considering the functional programming
>     trend in Ruby and other languages, we will see anonymous function
>     expression more often in the future.

There is also Ara's suggestion of using "def" for this purpose:

        http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/16804

This would make Ruby more consistent with other languages:

   Ruby
      def name; "stuff"; end
      name = def() "stuff"; end
 
   Perl 5
      sub name { "stuff"; }
      $name = sub { "stuff"; }

   JavaScript
      function name(){ "stuff"; }
      name = function(){ "stuff"; } 

(Perl 6 is not really worth considering, since there's not much evidence
it will actually ship.)

> There could be a chance for the keyword like "fun" or "fn", but
> there's little hope.

Hopefully a solution can be found that the core team is happy with. 
Personally,
I have seen many people in opposition to the use of "->" to mean lambda in
this context.  I think a better alternative can be found.

Thanks for your consideration.

Nate Wiger
PlayStation