From: Eric Mahurin <eric_mahurin@...>
Date: 2005-08-05T08:59:47+09:00
Subject: Re: new block notation (was: Re: ruby-dev summary 26468-26661)

--- Yukihiro Matsumoto <matz@ruby-lang.org> wrote:
> |f = { : a,b=1|2 : ... }
> |f = { : * : ... } # equivalent to f = lambda { ... }
> 
> Unfortunately :+space causes conflicts as well.

It does?  How so?  I said :+space to not conflict with the
:symbol syntax (could be a hash), just like the ? : operator. 
I also don't think this conflicts with the ? : operator.  If
you have this:

f = { : a = cond ? x : y : ... }

That middle : should obviously be interpreted as part of the ?
: operation.  Similar to the way a newline doesn't terminate a
statement if it is in the middle of the statement.

Another option would be to use the ;/newline punctuation to
separate the args from the code:

f = { : a, b ; ... }

or

f = { : a, b
    ...
}

If you didn't have to deal with hash ambiguities and you could
say that the arg list is required, I'd suggest this (remove the
: above):

f = { a,b ; ... }
f = { a,b
    ...
}
f = { ; ... }
f = {
    ...
}

To me that is about the prettiest you could get.  Just my 2
cents.

BTW, I noticed that lambdas without args now is interpreted as
no args allowed instead of any number of args allowed:

f = lambda { "xyz" };p(f["hi"])

wrong number of arguments (1 for 0) (ArgumentError)

1.8.2 allows this.  Was this change intentional?




		
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