Nice. -- Raul
On Mon, Mar 14, 2016 at 11:22 PM, Marshall Lochbaum <[email protected]> wrote: > I just stumbled across the following snippet. Platform independent, > constant time (for those with 2048-bit processors, naturally), and only > nine characters! > > 33 b.~ _1 > 9223372036854775807 > > The verb (33 b.), not often used in J, is the unsigned shift operator, > like C's (<<). When the left operand x is positive, it has the same > effect as multiplying y by (2^x). If x is negative and y is positive, it > is the same as division by (2^-x) followed by rounding down. However, if > x and y are both negative, then y is shifted as an unsigned integer: all > of its bits are moved right by (|x), and (|x) zeros are added on the > left. > > If y is _1, then its two's complement representation is all ones. > Shifting right by one leaves a number represented by a zero and then all > ones--the largest possible positive integer. > > If you want both the maximum and minimum integers: > MIN_INT =: <:- MAX_INT =: 33 b.~ _1 > > Marshall > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
