README

NAME
     Nim implementation of the Sitmo parallel random number generator

DESCRIPTION
     This implementation in Nim follows the original C++
     implementation from Sitmo.  The implementation is based on a
     paper by John Salmon and Mark Moraes and described in their
     paper “Parallel Random Numbers: As Easy as 1, 2,
     3”. (Proceedings of 2011 International Conference for High
     Performance Computing, Networking, Storage and
     Analysis). The algorithm is based on the Threefish
     cryptographic cipher.  It is usable for large scale parallel
     processing:

          1. O(1) and neglect-able skip ahead cost for block and
             leap-frogging parallelism.
          2. 32 bit seed offers 2^32 (4 billion) parallel random
             streams of length 2^256.
          3. Streams are guaranteed to be non-overlapping.

     The object, `sitmo', contains the state of the RNG.  The
     procedure `newsitmo' creates such object.  `seed' seeds the
     RNG, and `random' returns a `uint32' random number while
     advancing the internal state of the RNG.  There is only O(1)
     skip ahead cost, and the procedure `skip' advances the state
     of the RNG by a given amount (`uint64').  For details, see
     the documentation file `doc/sitmo.html'.

SYNOPSIS
     type sitmo* = object
       s*,k*,o*: array[4,uint64]
       oCounter*: uint16
     proc seed*(r:var sitmo)
     proc seed*(r:var sitmo, s:uint32)
     proc newsitmo*:sitmo
     proc newsitmo*(s:uint32):sitmo
     proc newsitmo*(r:sitmo):sitmo
     proc random*(r:var sitmo):uint32
     proc skip*(r:var sitmo, z:uint64)
     proc `==`*(x,y:sitmo):bool
     template `!=`*(x,y:sitmo):bool
     proc setKey*(r:var sitmo, k0,k1,k2,k3:uint64 = 0)
     proc setCounter*(r:var sitmo, s0,s1,s2,s3:uint64 = 0; oCounter:uint16 = 0)

EXAMPLES
     import sitmo
     var r = newsitmo()
     r.seed(0x7FFFFFFFu32)
     echo r.random
     r.skip(0xFFFFFFFFFFFFFFFFu64)
     echo r.random

LICENSE
     This work is licensed under the MIT license.  See file
     LICENSE for details.

SEE ALSO
     Sitmo PRNG: https://www.sitmo.com/?p=1206