/* 

  Ahl's Benchmark in Picat.

  From https://twitter.com/Frinklang/status/1620698584424546306
  """
  Is your computer (or phone) faster than a Cray-1 supercomputer?  Here's a 
  benchmark from Creative Computing magazine from March, 1984:

  Original article:
  https://archive.org/details/creativecomputing-1984-03/page/n7/mode/1up

  Frink program:
  https://frinklang.org/fsp/colorize.fsp?f=AhlsBenchmark.frink

  Frink runs it in 0:00.003 on my laptop after JVM warmup.
  """

  This Picat program is a port of Alan's Frink code:
  https://frinklang.org/fsp/colorize.fsp?f=AhlsBenchmark.frink
  """
  Ahl's simple benchmark, Creative Computing March 1984, P. 6

  https://archive.org/details/creativecomputing-1984-03/page/n7/mode/1up
  """


  Running from command line:

  $ time picat -g "time(go)" ahls_benchmark.pi 
Accuracy: 6.821210e-13
Random:   4.1
Time:     0ms

Accuracy: 6.821210e-13
Random:   1.0
Time:     1ms

Accuracy: 6.821210e-13
Random:   2.4
Time:     0ms

Accuracy: 6.821210e-13
Random:   10.5
Time:     0ms

Accuracy: 6.821210e-13
Random:   23.6
Time:     2ms

Accuracy: 6.821210e-13
Random:   8.1
Time:     1ms

Accuracy: 6.821210e-13
Random:   7.5
Time:     1ms

Accuracy: 6.821210e-13
Random:   15.0
Time:     0ms

Accuracy: 6.821210e-13
Random:   16.5
Time:     0ms

Accuracy: 6.821210e-13
Random:   11.1
Time:     0ms

CPU time 0.005 seconds.

picat -g "time(go)" ahls_benchmark.pi  0,02s user 0,02s system 98% cpu 0,041 total


  Running from the Picat REPL gives the about same performance: the CPU time
  ranges from 0.001..0.01

  This program was created by Hakan Kjellerstrand, hakank@gmail.com
  See also my Picat page: http://www.hakank.org/picat/

*/

main => go.

go =>
  statistics(runtime,_),
  foreach(_Times in 1..10) 
    statistics(runtime,[_,Start]),
    S = 0,
    R = 0,
    foreach(N in 1..100)
      A = N,
      foreach(I in 1..10)
         A := sqrt(A),
         R := R + frand()
      end,

      foreach(I in 1..10)
         A := A**2,
         R := R + frand()
      end,
      S := S + A
    end,
    printf("Accuracy: %e\n",abs(1010-S/5)),
    printf("Random:   %3.1f\n",abs(1000-R)),
    statistics(runtime,[_,End]),
    printf("Time:     %dms\n",End-Start),
    nl
  end,  
  nl.