Unification of variables and methods

ruby-talk
1

The one thing that bothers me about ruby is the (as i see it?) separate
namespaces for locals and functions.

Variables take precedence, but you can override and get the functional
form in 2 ways:

  def x; 1; end
  x = 2
  x # => 2
  x() # => 1
  self.x # => 1

1. It seems somewhat messy, and prohibits using () as a message (eg,
sending :call)

  x = proc { 1 }
  x() # NoMethodError...
  x[] # => 1

2a. It also leads to a more complex language to parse, and to those
interesting issues like:

  def x; 1; end
  x # => 1
  x = 2 if false
  x # => nil

2b. And other confusion as `*', '&' and '/' being mistaken at times,
with certain whitespace dependencies:

  def foo1; end
  foo2 = ''

  foo1 / 1 # this / is division
  foo1 /1 # this / starts an (as-yet unterminated) regexp.
  foo2 / 1 # this / is division also
  foo2 /1 # this / is also division! yet actually IRB trips up, looks
            # for the rest of /, then gives a SyntaxError on
compilation.

  a = [1, 2]
  foo1 * a # * means splat
  foo2 * b # * means multiply

I don't understand why they both just can't get along? :slight_smile:
(ie at least in the same namespace, optionally with parsing not
dependent on the guessed type).

···

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2

Hi,

The one thing that bothers me about ruby is the (as i see it?) separate
namespaces for locals and functions.

I think unification makes

  obj.foo

to retrieve foo method object a la Python, which I believe is not the
best way for programmers. In short, I took CommonLisp way over
Scheme way.

Some points you have pointed are negotiable.

              matz.

···

In message "Re: Unification of variables and methods" on Sat, 17 Feb 2007 14:16:24 +0900, Charles Lowe <aquasync@gmail.com> writes:

3

Yukihiro Matsumoto wrote:

Hi,

>The one thing that bothers me about ruby is the (as i see it?) separate
>namespaces for locals and functions.

I think unification makes

  obj.foo

to retrieve foo method object a la Python, which I believe is not the
best way for programmers. In short, I took CommonLisp way over
Scheme way.

Some points you have pointed are negotiable.

              matz.

Thanks for the response. In some ways i suppose, I've always found
scheme somehow more elegant that commonlisp, so perhaps we are looking
for different things...

I think though, that unification of vars/methods, and whether a bare
method name should auto-apply (as it were) are orthogonal? And I
certainly don't advocate the removal of the latter (ie obj.foo returning
a method object). That is part of what gives ruby its beauty IMO.
A unified namespace does pave the way for () to map to #call (although
such semantics aren't required), and it doesn't preclude the use of
plain methods.
Rather consider something like this:

  def foo
    ...
  end

  bar = proc { ... }

  foo # calls a method
  foo() # also calls a method
  method(:foo) # gets method object (proc)
  bar # gets a proc
  bar() # calls that proc

Its merely a syntactic sugar i guess, but in a way, you then have the
option of doing things python style, which is not my intention, and
possibly undesirable.

I think that the semantics are neater in the before mentioned case of
collisions:

  def x; 1; end
  x = 2
  x # => 2
  x() # => 1

If that final one were to either try to #call the x variable, or throw a
runtime error, or something, it would be (IMO of course) better.

In order to try to fake it for local variables, i tried this hack
once-upon-a-time:

  def method_missing(sym, *args, &block)
    sym = sym.to_s
    error = NameError.new "undefined local variable or method `#{sym}'"
    Binding.of_caller do |binding|
      raise error unless eval('local_variables', binding).include?
sym.to_s
      func = eval(sym, binding)
      raise error unless func.respond_to? :call
      func.call(*args, &block)
    end
  end

At any rate, just glad you've considered it - Ruby is great, so I trust
your judgement :slight_smile:

···

In message "Re: Unification of variables and methods" > on Sat, 17 Feb 2007 14:16:24 +0900, Charles Lowe > <aquasync@gmail.com> writes:

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