Re: [PATCH] lambda with normal block syntax

Hi --

On Tue, 27 May 2008, Yukihiro Matsumoto wrote:

> Hi,
>
> In message "Re: [PATCH] lambda with normal block syntax"
>    on Mon, 26 May 2008 23:14:56 +0900, Dave Thomas <[e-mail]> writes:
>
> |You asked people to try the patched syntax that allows
> |
> |   meth {|a| a+1}, {|b| b*2}
> |
> |I think that this particular syntax is a lot less obtrusive, and a lot
> |easier to recognize, than
> |
> |   meth -> a { a + 1}, -> b { b * 2 }
> |
> |The first one is obviously a couple of blocks: that's what I read when
> |I see {|a| ...}.
> |
> |It seems that most of the posters on this thread agree. And, using
> |your criteria of "try it for a while and see", I'd judge that people
> |have tried -> for a while, and might well be happier with the {|| }
> |version.
>
> Personally I don't like
>
>   meth {|a| a+1}, {|b| b*2}
>
> which can be parsed
>
>   (meth() {|a| a+1}), ({|b| b*2})
>
> or
>
>   meth({|a| a+1}, {|b| b*2})
>
> or whatever.  I dislike this kind of ambiguity.  In fact, you would
> expect the latter, but I'm afraid Eric's patch gives you the former.
> This could be a very evidence of (bad) ambiguity.  That's why I asked
> people to try the patch.

Maybe the same rule could be applied to {||...} lambda objects (as
opposed to the code block) that is now applied to hashes:

   meth {}     # code block
   meth({})    # one hash argument
   meth {||}   # code block
   meth({||})  # one lambda object argument


David

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