Re: Execution speed Nim vs. Python

[def]

@yglukhov: Ah, you don't make copies of the entries of Directions. I think 
that's an optimization the compiler should be able to do somehow. Also, you can 
use `0 .. Directions.high` instead of `0 ..< Directions.len`. Using `mitems` 
instead achieves the same effect, but needs a `var`:
    
    
    # Nim example to test execution speed against a Python version
    import times, os
    
    const
      board = ['0', 'p', '.', 'p', 'P', '.', 'p', 'P', '.', 'p', '.', 'p', 'P', 
'.', 'p']
      NE = [8, 2, 13, 4, 5, 7, 8, 3, 9, 12, 7, 8, 3, 9, 12]
    var Directions = [NE, NE, NE, NE]  # for short: in real application the 
array elements differ
    
    proc do_something(board: openarray[char]): seq[char] =
      result = newSeqOfCap[char](board.len * Directions.len)
      for i in 0 .. board.high:
        for d in Directions.mitems:
          result.add board[d[i]]
    
    let t0 = cpuTime()
    var res: seq[char]
    const count = 100_000
    for i in 1..count:
      res = do_something(board)
    let t1 =  cpuTime()
    echo "***** Time elapsed for Nim: ", t1 - t0, "  Counts: ", count
    echo res.repr