From: murphy <murphy@...>
Date: 2007-12-13T16:39:45+09:00
Subject: Re: redefineable not operator

Yukihiro Matsumoto wrote:
> This case, it's more than having two names.  Those two should act
> identical.  But I understand your concern.  Let me think about it.
while we're at it:
- why does Symbol.all_symbols return :"!" twice?
- is there a way to print a list of all Symbol equivalence classes with
  more than one member? I have found:

:"+"  == :"+(binary)"  # => true
:"+@" == :"+(unary)"   # => true
:"-"  == :"-(binary)"  # => true
:"-@" == :"-(unary)"   # => true
:"~"  == :"~@"         # => true
:"~"  == :"~(unary)"   # => true
:"~@" == :"~(unary)"   # => true
:"!"  == :"!@"         # => true
:"!"  == :"!(unary)"   # => true
:"!@" == :"!(unary)"   # => true

# and the way around:
:"+(binary)" == :"+"   # => true
:"+(unary)"  == :"+@"  # => true
:"-(binary)" == :"-"   # => true
:"-(unary)"  == :"-@"  # => true
:"~@"        == :"~"   # => true
:"~(unary)"  == :"~"   # => true
:"~(unary)"  == :"~@"  # => true
:"!@"        == :"!"   # => true
:"!(unary)"  == :"!"   # => true
:"!(unary)"  == :"!@"  # => true

(Ruby 1.9 _and_ 1.8, surprisingly.) is this complete?

- what determines the "real" value of a symbol (that I get when
inspecting or printing it)? is it a rule that the shortest variant
always wins?

:"+"         # => :+
:"+@"        # => :+@
:"-"         # => :-
:"-@"        # => :-@
:"~"         # => :~
:"~"         # => :~
:"~@"        # => :~
:"!"         # => :"!"
:"!@"        # => :"!"
:"+(binary)" # => :+
:"+(unary)"  # => :+@
:"-(binary)" # => :-
:"-(unary)"  # => :-@
:"~@"        # => :~
:"~(unary)"  # => :~
:"!@"        # => :"!"
:"!(unary)"  # => :"!"

[murphy]