57 lines
1.8 KiB
Factor
57 lines
1.8 KiB
Factor
! :folding=indent:collapseFolds=1:
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! $Id$
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!
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! Copyright (C) 2004 Slava Pestov.
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!
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! Redistribution and use in source and binary forms, with or without
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! modification, are permitted provided that the following conditions are met:
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!
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! 1. Redistributions of source code must retain the above copyright notice,
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! this list of conditions and the following disclaimer.
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!
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! 2. Redistributions in binary form must reproduce the above copyright notice,
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! this list of conditions and the following disclaimer in the documentation
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! and/or other materials provided with the distribution.
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!
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! THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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! INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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! FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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! DEVELOPERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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! SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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! PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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! OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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! WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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! OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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! ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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IN: random
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USE: arithmetic
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USE: kernel
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USE: stack
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: power-of-2? ( n -- ? )
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dup dup neg bitand = ;
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: (random-int-0) ( n bits val -- n )
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3dup - + pred 0 < [
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2drop (random-int) 2dup swap mod (random-int-0)
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] [
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nip nip
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] ifte ;
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: random-int-0 ( max -- n )
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succ dup power-of-2? [
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(random-int) * 31 shift>
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] [
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(random-int) 2dup swap mod (random-int-0)
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] ifte ;
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: random-int ( min max -- n )
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dupd swap - random-int-0 + ;
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: random-boolean ( -- ? )
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0 1 random-int 0 = ;
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! TODO: : random-float ... ;
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