From: _why <why@...>
Date: 2008-05-23T02:56:22+09:00
Subject: Re: lambda, ->, haskell, and so on

On Tue, May 20, 2008 at 01:54:17PM +0900, ara.t.howard wrote:
> On May 19, 2008, at 11:23 AM, Yukihiro Matsumoto wrote:
>> There could be a chance for the keyword like "fun" or "fn", but
>> there's little hope.
> 
> i really think the path of least resistance and easiest adoption is using 
> 'def', despite the semantic conflict.  ruby is so great at maintaining 
> context sensitive POLS over rigid uniformness it's a natural option
> 
>  x = def() 'people already would understand this' end

So drop the `do`?  Does this keyword work with curly braces?

  x = ->do 'presenting the amazing arrow syntax!!' end
  x =   ->{ 'nicer without space after the arrow' }

--

So I guess it would be...

  module Kernel
    define_method :call1, &def(x, &y)
      y[x]
    end
  end
  p call1(3) { |a| a + 1 }

Vs:

  module Kernel
    define_method :call1, &->x, &y do
      y[x]
    end
  end
  p call1(3) { |a| a + 1 }

Although everyone really uses:

  module Kernel
    define_method :call1 do |x, &y|
      y[x]
    end
  end
  p call1(3) { |a| a + 1 }

--

Personally, could see this syntax most handy for stuff like
assigning multiple events at once in Shoes:

  image.click ->{ image.hide },
    ->{ image2.show }

Not as fond of `def`:

  image.click def() { image.hide },
    def() { image2.show }

I didn't like the arrow syntax at all, but after using it, I
get it.  And with blocks being able to handle |x,*a,&b|, I don't
use lambdas as much.

_why