[REBOL] Re: Arithmetic shifts
From: carl:cybercraft at: 17-Aug-2004 19:54
>Note that to-integer (or to integer!) isn't always required to return an
>integer with division...
>
>>> type? 3 / 2
>== decimal!
>>> type? 4 / 2
>== integer!
>>> type? 12 / 4
>== integer!
>
>Which also allows us to do the likes of this...
>
>>> x: 5 and 254 / 2
>== 2
>>> type? x
>== integer!
>
>I suspect this has speed advantages too, though I've not done any tests.
Have now and indeed it does...
>> t: now/time/precise loop 1000000 [2 / 2]print now/time/precise - t
0:00:00.93
>> t: now/time/precise loop 1000000 [2 / 2]print now/time/precise - t
0:00:00.94
>> t: now/time/precise loop 1000000 [2 / 2]print now/time/precise - t
0:00:00.94
>> t: now/time/precise loop 1000000 [3 / 2]print now/time/precise - t
0:00:01.43
>> t: now/time/precise loop 1000000 [3 / 2]print now/time/precise - t
0:00:01.43
>> t: now/time/precise loop 1000000 [3 / 2]print now/time/precise - t
0:00:01.37
And using AND's quicker than TO INTEGER! too...
>> t: now/time/precise loop 1000000 [3 and 254 / 2]print now/time/precise - t
0:00:01.59
>> t: now/time/precise loop 1000000 [3 and 254 / 2]print now/time/precise - t
0:00:01.59
>> t: now/time/precise loop 1000000 [3 and 254 / 2]print now/time/precise - t
0:00:01.54
>> t: now/time/precise loop 1000000 [to integer! 3 / 2]print now/time/precise - t
0:00:02.85
>> t: now/time/precise loop 1000000 [to integer! 3 / 2]print now/time/precise - t
0:00:02.86
>> t: now/time/precise loop 1000000 [to integer! 3 / 2]print now/time/precise - t
0:00:02.8
-- Carl Read
