Yes, they both involved integer overflow. Some integer overflows are more serious than others.
Now, Arthur Whitney is not an ordinary mortal like you or me. When we get an integer overflow it's a bug. Arthur exploits integer overflow in a key part of the interpreter, and the J interpreter has benefitted from this invention since 2005. ----- Original Message ----- From: Devon McCormick <[EMAIL PROTECTED]> Date: Friday, November 17, 2006 6:47 pm Subject: Re: [Jprogramming] Oddities with /: > This sounds like it's related to the other bug I uncovered with > the large > vector of large vectors. > > On 11/17/06, Roger Hui <[EMAIL PROTECTED]> wrote: > > > > The machine integer overflow problem is responsible > > for "nearly all binary searches .. are broken", > > including the one in "Programming Pearls" by > > Jon Bently: > > > > > > http://googleresearch.blogspot.com/2006/06/extra-extra-read-all- > about-it-nearly.html > > > > When you look at x+y and you know that x and y are > > non-negative, it is very difficult to be alert to > > the fact that x+y can be negative! > > > > > > > > ----- Original Message ----- > > From: Roger Hui <[EMAIL PROTECTED]> > > Date: Friday, November 17, 2006 8:03 am > > Subject: Re: [Jprogramming] Oddities with /: > > > > > I have found and fixed the bug for the next release. > > > Thanks for finding and reporting this error. > > > > > > The error is in a calculation that involves the > > > vector length and the maximum value, to decide which > > > sort algorithm to use. The example you found has > > > the right combination to cause machine integer > > > overflow. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
