> Lähettäjä: E S <eero.saynatkari@kolumbus.fi>
> Aihe: Re: nil question
>
> > Lähettäjä: E S <eero.saynatkari@kolumbus.fi>
> > Aihe: Re: nil question
> >
> > > Lähettäjä: "David A. Black" <dblack@wobblini.net>
> > > Aihe: Re: nil question
> > >
> > > Hi --
> > >
> > > On Mon, 31 Jan 2005, Christian Neukirchen wrote:
> > >
> > > > "David A. Black" <dblack@wobblini.net> writes:
> > > >
> > > >> Hi --
> > > >>
> > > >> On Sun, 30 Jan 2005, Christian Neukirchen wrote:
> > > >>
> > > >>> "William James" <w_a_x_man@yahoo.com> writes:
> > > >>>
> > > >>>> Sam Roberts wrote
> > > >>>>> In ruby, zero and empty strings are true
> > > >>>>
> > > >>>> Since 0 is true, you should be able to do this in Ruby:
> > > >>>>
> > > >>>> puts "yes" if -5 < x < 9
> > > >>>>
> > > >>>> The phrase '-5 < x' should yield the value of x instead of true.
> > > >>>> That's the way it actually works in the Icon programming language.
> > > >>>> But we have to use the klunky
> > > >>>>
> > > >>>> puts "yes" if -5 < x and x < 9
> > > >>>>
> > > >>>
> > > >>> Erm, say, x is -16:
> > > >>>
> > > >>> (-5 < x) < 9
> > > >>> (-5 < -16) < 9
> > > >>> -5 < 9
> > > >>> -5
> > > >>>
> > > >>> -5 is true, probably not what you want.
> > > >>
> > > >> But -5 < -16 is not true, so it wouldn't get that far. (I assume
> > > >> William means it should return x if the expression is true, false
> > > >> otherwise.)
> > > >
> > > > So false is bigger than 9? Math books will need to be rewritten. :-)
> > >
> > > I assume the expression would short-circuit once one of the
> > > sub-expressions returned false, since
> > >
> > > x < y < z
> > >
> > > cannot be true unless x < y. So there would never be a false < z
> > > comparison.
[Snip my inanities]
Wow. I'm so dense today no wonder I've had stuff hurling towards me. Wonder if I could patent a caffeine capsule that starts dissolving
after 6-7 hours?
Anyway. Looks like Fixnum and Float define < and >, whereas Bignum
and Complex only define <=>
module MultiComparable
def <(val)
val if self.<=>(val) == -1
false
end
def >(val)
val if self.<=>(val) == 1
false
end
end
# Modify the existing units
class FalseClass
def <(val)
false
end
end
class Fixnum; include MultiComparable; end
class Bignum; include MultiComparable; end
class Float; include MultiComparable; end
class Complex; include MultiComparable; end
Would that do it (this is real XP, I don't even have a compiler:)?
E