From: gabriele renzi <surrender_it@...1.vip.ukl.yahoo.com>
Date: 2004-06-01T17:23:42+09:00
Subject: Re: Andreas' practical language comparison

il Sun, 30 May 2004 17:25:03 +0200, Hynek Schlawack
<hynek+usenet@hys.in-berlin.de> ha scritto::

>* "Robert Klemme" <bob.news@gmx.net> wrote:
>
>>> It looks like Ruby is missing in "Andreas' practical language
>>> comparison" (Here's the page
>>> http://www.kochandreas.com/home/language/lang.htm) I guess it'd be
>>> nice if Ruby won an appropriate place in the competition.
>> Partly done.  Some shorties there.  Any volunteers for GUI stuff?
>
>I found time to do "Red Ball" just now, hope no one else was faster. I
>think it looks pretty cool in ruby (dunno if it goes even
>better). Especially comparing it to the python-version...

I believe some little tweaks may make this little more rubyish:
get rid of global variables using a constant, a local, and defining
move_player as a singleton method of the canvas object

#!/bin/env ruby

# We use the Tk-Toolkit
require 'tk'

# Create a root-widget, a canvas and a hash to store the squares
root = TkRoot.new { title "Red Ball" }
canvas = TkCanvas.new(root) { width 320; height 200 }
Fig = Hash.new

# Create the squares with the appropriate colors on random places
['black', 'red'].each do | colour |
  x = (rand * (320 - 16)).to_i
  y = (rand * (200 - 16)).to_i
  Fig[colour] = TkcRectangle.new(canvas, x, y, x+15, y+15, 'fill' =>
colour)
end

canvas.pack

# Move the square in the desired direction, exit if we have won
def canvas.move_player(x, y)
  move(Fig['red'], x, y)
  exit if (coords(Fig['red']) == coords(Fig['black']))
end

# Bind the actions to keys
root.bind("s") { canvas.move_player(-1,  0) }
root.bind("d") { canvas.move_player( 1,  0) }
root.bind("e") { canvas.move_player( 0, -1) }
root.bind("x") { canvas.move_player( 0,  1) }

# Finally give up control to Tk
Tk.mainloop