Tom Cloyd wrote:
OK, let's assume we have the language problem solved (ha! - not likely
to happen). Nann-methods == "non-alphabetically-named methods".
That's not exactly the same though. You can (with a bit of work) define
arbitrary methods with non-alphanumeric names, but they are not
operators.
The things we're talking about are called "operators" because they look,
syntactically, like operators in other languages, and are parsed as
such.
foo + bar # infix binary plus (method +)
- foo # prefix unary minus (method -@)
That is: "arg1 op arg2" instead of "arg1.methodname(arg2)"
The fundamental thing is that the infix/prefix notation shown above is
parsed successfully, but then translated into normal method calls. You
can then define or redefine these methods, just like any other methods.
class Foo
def -@
"minus #{self}"
end
end
f = Foo.new
p -f # operator notation (unary minus)
p f.-@ # same but using explicit method call
The core
problem still remains - what the blazes does that THING
do/mean/produce...???
It produces whatever it is defined to produce 
That is, class Foo may or may not implement the unary minus
operator/method (or any other operator). If it does, it is the
programmer's choice as to what it does.
Equally, I could define a method Foo#xcikuhruh. It would be my choice
what it does
You may have an implicit expectation of, say, what the "*" operator
does, i.e. multiplication. But it may not make sense in non-numeric
contexts. For example, the facets library defines a way to combine Proc
objects using *:
----------------------------------------------------------------- Proc#*
*(x)
···
------------------------------------------------------------------------
Operator for Proc#compose and Integer#times_collect/of.
a = lambda { |x| x + 4 }
b = lambda { |y| y / 2 }
(a * b).call(4) #=> 6
(b * a).call(4) #=> 4
CREDIT: Dave
An operator precedence table shows all the operators known by Ruby, and
the ways they interact with each other in complex expressions. It
doesn't make sense to include what they "mean", because they will mean
different things when applied to different objects. And the joy is, you
can make them mean whatever you like when applied to *your* objects.
A neat trick I've seen is a pathname class which uses the '/' operator
to compose paths: e.g.
path1 = MyPath.new("home")
path2 = path1 / "bar" / "baz" # results in /home/bar/baz
Saying that the '/' operator means "division" doesn't make sense here.
HTH,
Brian.
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