From: Quinn Dunkan <quinn@...>
Date: 2000-03-16T16:38:10-08:00
Subject: [ruby-talk:01941] Re: ruby <=> python


> I think a byte is a integer in range between 0 and 255, Ruby does give
> you a integer from 0 to 255 by [], although it does not provide the
> special type for the range.  Do you mean there's need for a integer
> type to represent a byte only?
> 
> If so, what characteristics a byte type should have?  What is the
> difference between signed int and byte.

Actually, on second thought, I conceed that Fixnum makes a perfectly good
byte (since all types are probably boxed in ruby anyway, size difference is
hardly relevant... I think).  As far as characteristics go:

Char + String -> String
Char + Fixnum -> TypeError
Char#inspect -> 'x' or '\0xyz' if not in "normal ascii range"

But I'm probably being ascii-latin1-biased by assuming there's a such
thing as "normal ascii range" that makes sense for evenyone.

> I'm not sure I understand your point, mostly because my English skill.
> `::' is needed for nested constant access.  Its syntax is
> 
>   A::F

It is (needed)?  Why wouldn't A.F work?  Oh wait, I see... methods can be
capitalized.

> There are other combinations like:
> 
>   A::F()
>   A::f
>   A::f()
> 
> I made these method invocation to allow programmer to add optional
> information to show the receiver is a class.  This is not enforced by
> the language, just as a optional variation.

I think you understood ok:
My point was that if `::' can behave as a `.', you can't look for class
methods by looking for `::'s, because many people will use `.' for that, and
some people might even use `::' for instance methods.  I think your point was
that it's ``optional documentation'' like arg names in declarations in C,
which I also understand.  Just a difference of opinion, then.  That paragraph
about ``optional information to show receiver is a class'' is good
documentation.  The whole constant-access thing must be ``one of those C++
things''...

> |> `false' is a boolean value, `nil' is a out-of-range value.  You know I mean?
> |> I'm considering make 0 false, but not positively.
> |
> |Uh oh, does that mean only -0 is false?  My head hurts.
> 
> NO.  I mean I had considered to make 0 falise; I haven't refused it
> yet, but not eager to adpot.  `positively' did not mean number
> positiveness.

I know, I was just trying to be cute... sorry for any confusnion :)
(but confusion is so much fun!)

[parallel iteration]
> You can solve this by defining external iterator.
>  
>   class ArrayIterator
>     def initialize(ary)
>       @ary = ary
>       @index = 0
>     end
>     def next
>       if @index >= @ary.size
>         raise IndexError, "index out of range"
>       end
>       value = @ary[@index]
>       @index += 1
>       value
>     end
>   end
> 
>   def zip(*args)
>     r = []
>     iter = args.collect{|i|ArrayIterator::new(i)}
>     begin
>       loop do
> 	r.push iter.collect{|i|i.next}
>       end
>     rescue IndexError
>     end
>     r
>   end

Interesting... I should try to think in iterators/generators for a bit..