From: Dennis Decker Jensen <dennisdecker@...>
Date: 2001-05-06T04:16:27+09:00
Subject: [ruby-talk:14719] SV:  Why's Ruby so slow in this case?

Stefan Matthias Aust wrote:
| I wonder whether there are some ways to optimize this code other than
| to completely change the algorithm.  Or can the Ruby interpreter be
| improved?  I'm using Ruby 1.6.4 if that matters.

Oh! I just remembered. Predefining variables used in a loop should increase
the performance AFAIK.

| def initmap
|   count = $mapsize * $mapsize
|   $hexes = (0...count).map{Hex.new}
|
|   $hexes[rand(count)].terrain = Terrain::Mountain
|
|   for i in 0...(count / 2 - 1)
|     a = []

	h = 0
	^^^^^
|     for h in 0...count
|       if offshore(h) then a << h end
|     end
|     h = a[rand(a.length)]
|     $hexes[h].terrain =
|       case rand(3)
|         when 0; Terrain::Plain
|         when 1; Terrain::Forest
|         when 2; Terrain::Mountain
|       end
|   end
| end
|
| def offshore(h) #private
|   if $hexes[h].iswater

	d = h2 = 0
	^^^^^^^^^^
|     for d in 0..5
|       h2 = displace(h, d)
|       if h2 >= 0 && !$hexes[h2].iswater
|         return true
|       end
|     end
|   end
|   false
| end

Hope this helps a bit.

Best regards,

Dennis Decker Jensen