[ruby-core:24588] Re: [Bug #1828] 1/-20 == -1 ?

Heesob Park wrote:
> Dividing positive number by negative number returns incorrect value.
> 
> irb(main):001:0> 1/-20
> => -1

Fixnum#/ rounds down. More precisely: it uses divmod and throws away the 
mod:

1.divmod -20 # => [-1, -19]

The -1 is because fixdivmod() has a special case that subtracts 1 from 
the dividend if modulus > 0 and denominator < 0. Which satisfies:

(-10..10).each do |x|
   (-10..10).each do |y|
     next if y == 0
     div, mod = x.divmod y
     raise unless x == div*y + mod
   end
end

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407