From: Eric Mahurin <eric_mahurin@...>
Date: 2005-05-27T23:50:26+09:00
Subject: Re: will callable objects be more general in Ruby 1.9?



--- Yukihiro Matsumoto <matz@ruby-lang.org> wrote:
> |In terms of compatibility, I assume you are referring to the
> |fact that if you have a local variable f (callable or not),
> f()
> |will try to call it even if the method f exists (in 1.9).  I
> |like this new behavior (local variables always override),
> but
> |to preserve compatibility couldn't you just change the
> |priority? - f() would prefer calling method f over calling
> |local variable f.
> 
> The priority idea is interesting.  My two concerns are:
> 
>   * it might make it hard for humans to understand what code
> does, by
>     introducing runtime ambiguity.
>   * I'm not sure if yacc allows that kind of priority
> resolution.

I would assume it would be workable because you already have to
deal with priority between local variables and methods - "xyz"
will prefer accessing local variable xyz over calling method
"xyz".

If this is still not wanted, another option would be to allow a
block to follow the [] operator (and be associated with it).  I
think this is a much smaller change to the language.  This way
you could do something like this:

f = {|*args,&block|...}

f["hello","world"] {puts("bye")}

which has the same conciseness as:

f("hello","world") {puts("bye")}

and allows "f" to be an arbitrary object expression.  The main
downside is that the [] is necessary so that you can't say:

f {puts("bye")}



		
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