From: stevetuckner <stevetuckner@...>
Date: 2005-10-20T04:45:32+09:00
Subject: Re: Method annotation and anonymous functions

David A. Black wrote:

> Hi --
>
> On Thu, 20 Oct 2005, stevetuckner wrote:
>
>> I want to start a discussion about two things that Matz talked about 
>> at the rubycon. Dave Thomas suggested that we could get Matz' 
>> anonymous function by using "def" without a name. Others suggested 
>> that if def returned a method object, then annotations could be 
>> applied to that object. So here goes my suggestions. As they stand, 
>> they are not even parseable by Ruby, but lets start talking about it 
>> anyway.
>>
>> Anonymous functions:
>>
>> x = def (a=1,b=2) { ... }
>> y = def(a,b=3) begin
>>   .....
>> end
>
>
> I don't think either of those is exactly what Dave suggested:
>
>   x = def (a=1,b=2)
>         ...
>       end

What I don't like about this is that to do one liners, you need to do:

x = def(a=1, b=2); ...; end

>
> without the braces, and without 'begin', just like a method
> definition.
>
> I actually like the second iteration of the idea more:
>
>   x = lambda (a=1,b=2)
>         ...
>       end

same issue

>
> using method-definition style for an anonymous function, but a
> different keyword.  This keeps it more robust; there's a more "solid"
> indication that it's something other than a def.

I don't mind lambda over def. What object would lambda return? A proc 
object? Could annotations be applied to it?

>
> (Actually that was sort of the third iteration :-)  The first was:
>
>   -> (a=1,b=2)
>     ...
>   end
>
> which I posted here last week in an attempt to at least ameliorate the
> arrow thing.  But having a real keyword plus the no-braces is
> definitely better.)
>
>
>
> David
>