From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2009-01-14T19:12:58+09:00
Subject: Re: Higher order ruby

On Wed, Jan 14, 2009 at 11:09 AM, zslevi <zslevi@gmail.com> wrote:
> foo = lambda {|x| lambda {|y| return x+y}}
>
> foo.call(3)(4)
>
> Why this doesn't work? I expected lamdas to behave like in SML.

When you call foo, or apply it with [], you get another lambda in return.
To call that lambda you have to use call again, or []:

irb(main):001:0> foo = lambda {|x| lambda {|y| return x+y}}
=> #<Proc:0xb7bb5f28@(irb):1>
irb(main):002:0> foo[3][4]
=> 7
irb(main):003:0> foo.call(3).call(4)
=> 7

Jesus.