From: Trans <transfire@...>
Date: 2005-11-04T12:27:09+09:00
Subject: Some comments on new 1.9 features

Just looking at http://eigenclass.org/hiki.rb?Changes+in+Ruby+1.9.
Nicely done!

Comment on a couple things

1) ;; instead of end

  It is possible to use ;; instead of end.

  (1..100).inject do |s,x|
    s+x
  ;;		# => 5050

  class Foo
    def foo; "foo" end
  ;;
  Foo.new.foo		# => "foo"

What's the rationle here? I'd rather have a punctutation mark for 'do'
(yes, ':' again ;-p)

  (1..100).inject: |s,x|
    s+x
  end		# => 5050

Of course could have both:

  (1..100).inject: |s,x|
    s+x
  ;;		# => 5050


2) Block local variables

  Used as follows:

  # {normal args; local variables}
  d = 2
  a = lambda{|;d| d = 1}
  a.call()
  d		# => 2

  When a variable is shadowed, ruby1.9 issues a warning:

  -:2: warning: shadowing outer local variable - d

Come on. This stinkos. At some point I think you have to give it up and
allow a declaration.


3) Calling Procs without #call/#[]

  You can now do:

  a = lambda{|*b| b}
  (a)(1,2)		# => [1, 2]

  Note that you need the parentheses:

  a = lambda{|*b| b}
  a(1,2)      # => ERROR: (eval):2: compile error...

I know this has been deprecated, but what causes this not to work
exactly?


4) send doesn't call private methods anymore

  ruby-talk:153672 It is still possible to call them with the newly
introduced #funcall method.

  class Foo; private; def foo; end; end
  Foo.new.funcall(:foo)		# => nil
  Foo.new.send(:foo)		# => ERROR: private method `foo' called for
#<Foo:0xb7e0e540>

No #funcall please, I already have enough methods to make exceptions
for in BlankSlate/BasicObject. Use #instance_send instead. Thank you.


5) Class of singleton classes

  singleton class inherits Class rather than its object's class

  class X;end; x=X.new; class << x; self < X; end		# => true

  vs. (1.8)

  class X;end; x=X.new; class << x; self < X; end		# => nil

Is this example backwards? I'm confused. Please confirm.


6) Class variables are not inherited

  ruby-dev:23808

 class A; @@a = 1; end; class B < A; @@a end # => ERROR: (eval):1:
uninitialized ...

  vs.

 class A; @@a = 1; end; class B < A; @@a end		# => 1

Love it! Thank you!


T.