[ruby-core:25061] Re: Proposal: Simpler block format

I was actually just discussing that with Ujihisa. Unfortunately, it would
break far too much code to be practical (think, every single Ruby script out
there).
-- Yehuda

On Sun, Aug 23, 2009 at 4:17 PM, <[e-mail]> wrote:

> > On Sun, Aug 23, 2009 at 3:33 PM, Yukihiro Matsumoto
> > <[e-mail]>wrote:
> >
> >> Hi,
> >>
> >> In message "Re: [ruby-core:25049] Re: Proposal: Simpler block format"
> >>     on Sun, 23 Aug 2009 15:53:03 +0900, Yehuda Katz <[e-mail]>
> >> writes:
> >>
> >> |Things that currently don't parse are fine to become blocks. I'd be
> >> worried
> >> |about a case that currently parsed fine as a Hash but might be expected
> >> to
> >> |be parsed as a block if this feature existed. Can you think of any?
> >>
> >> I don't worry about the ambiguity for the parser, but have anxiety for
> >> humans.  Under the new syntax, when we see
> >>
> >>  m {"this is a block not a proc"}
> >>
> >> there are two possibility.  And it would be burden for mind of the
> >> programmers.  That's the reason I insisted the past proposal (that
> >> was from David Black, IIRC).  This time, we have working code for the
> >> proposal, so we can try.  Let's see how we feel.
> >
> >
> > The compelling this for me is that it makes methods that take multiple
> > blocks easier for programmer to read. For programmer, one big confusion
> in
> > Ruby is difference between proc, block, lambda and method. Unifying
> syntax
> > for block and proc shows that they are really just same thing, with proc
> > passed as parameter and block passed as special parameter.
> >
> > Then whenever programmer sees { something } they know it is "proc" with
> > lexical scope, and whenever programmer sees ->{ something } they know it
> > is
> > "lambda" with function scope.
> >
> > I would even be in favor of def { } as lambda syntax, which would make
> > clear
> > to programmer that this block behaves just like normal method. Then we
> > have
> > just two things: def for method-scope (def something() end and def { })
> > and
> > bare { } for block scope.
>
> if we're throwing ideas out there, i've always thought it would be a good
> idea to do exactly what you've proposed, plus take { } away from hashes
> and use [ ] instead. that way { } is just for proc, method, etc., and [ ]
> is for arrays and hashes. what's inside of the [ ] determines whether it's
> an array or hash. thus:
>
> [1, 2, 4, 9]     # array
> [1 => 2, 4 => 9] # hash
> [a: 'b', c: 'd'] # hash
> [a: 'b', 1, 2]   # error or hash
> { ... }          # proc, always
> def { ... }      # method, lambda
> ->{ ... }        # method, lambda
>
> this breaks everything though. but we _are_ still in 1.9, and one can
> dream...
>
>
>


-- 
Yehuda Katz
Developer | Engine Yard
(ph) 718.877.1325