From: Trans <transfire@...>
Date: 2005-08-05T02:16:06+09:00
Subject: Re: ruby-dev summary 26468-26661


Yukihiro Matsumoto wrote:
> Hi,
>
> In message "Re: ruby-dev summary 26468-26661"
>     on Thu, 4 Aug 2005 22:38:06 +0900, "David A. Black" <dblack@wobblini.net> writes:
>
> |> I like it!  Looks much more uniform and consistent with function
> |> syntax than {|...| ...}
> |
> |I assume you mean method syntax.  But why is that important?  Until
> |this new syntax was posted, I'd never heard anyone complain that they
> |found it hard to recognize {|...| } as a code block.  Now there seems
> |to be a retroactive sentiment in the air that the block syntax is, and
> |always has been, obscure or garbled.
>
> lambda is an anonymous function, so that it requires full syntax of
> function/method argument, including optional arguments, keyword
> arguments, block arguments etc., not just parallel assignment as in
> plain block parameters.
>
> |If uniformity is important maybe def should be redesigned:
> |
> |   def x |a,b,c=1|
> |   end
>
> Stop joking. ;-)
> Unlike others, I have never given uniformity a top priority.

If lambda === Method (minus context), I don't think he would be joking.

  def x |a,&b|
    b[a]
  end

  x(1) def |a|
    a+1
  end

But that does nothing to solve | ambiguity. So forget 'em and go back
to parens:

  def x(a,&b)
    b[a]
  end

  x(1) def n(a,b)
    a+1
  end

Such that #def returns a lambda/Method. The name of the lambda, n,
would be local to the block, and while usually extraneous, it can be
useful as a reference to the block itself.

  [:a,:b,:c].each def n(i)
    p n.count;
  end
  #=> 1 2 3

That still leaves { } notation. If { == def and } == end, as D. Black
"jests", at first it seems ambiguous. But actually I don't think it is.

  x(1) { n(a,b) a+1 }

is decernable from:

  x(1) { n(a,b) ; a+1 }

for example.

Yet I agree, over unifority can be hard on the eyes. Which is why #do
makes a good substitute for #def in block contexts.

T.