From: Adam Shelly <adam.shelly@...>
Date: 2005-08-26T06:10:29+09:00
Subject: Re: [SUMMARY] Sodoku Solver (#43)

On 8/25/05, Ruby Quiz <james@grayproductions.net> wrote:
> I believe Adam Shelly's parse routine could benefit from similar simplifications
> if you want to try your own hand at a little refactoring.

Ok, I admit I'm a ruby newbie.  But I'm trying to learn the Ruby Way.
How's this?

Was:
def ParseBoard(file)
   row = 0
   col = 0
   boxes = 0
   boardlist = [ ]
   file.each do |line|
       line.chomp.each_byte do |c|
           case c
               when ?0..?9
                   boardlist << c.to_i - ?0
                   col+=1
               when ?A..?Z
                   boardlist << c.to_i - ?A + 10
                   col+=1
               when ?a..?z
                   boardlist << c.to_i - ?a + 10
                   col+=1
               when ?_
                   boardlist << -1
                   col+=1
               when ?+
                    boxes+=1 if row == 0
           end
       end
       if (col > 0)  then
           row+=1
           break if (row == col)
       end
       col=0
   end
   @@boxcols = boxes-1
   return boardlist,row
end

Is:
def ParseBoard(file)
    boardlist,size = [ ],0
    file.each do |line|
        if line.delete!('^0-9A-Za-z_+') =~ /\++/
            @@boxcols= line.length-1
        else
            boardlist += line.split(//).collect{|n| n.hex }
            size = line.length
        end
        p line
    end
    boardlist,size
end

The only difference is it adds 0's to the boardlist where it used to
add -1's, but the solver constructor handles anything outside 1..size
the same, so it doesn't matter.
It doesn't handle malformed input well, but neither did the old
version.  That's for another exercise, maybe.

-Adam