From: Gavin Kistner <gavin.kistner@...>
Date: 2007-06-08T03:36:45+09:00
Subject: Re: Mutually-Recursive Functions

From: bbiker [mailto:renard@nc.rr.com] 
Sent: Thursday, June 07, 2007 12:00 PM

[snip]
> 		return alpha_col[0] - 'A'[0] + 1
[snip]

I thought I'd point out that
  'A'[0]
is equivalent to
  ?A
...and I personally find the latter to be much more friendly.


For completeness, here's how I'd write the name-to-number conversion as
an auto-caching hash (without the bounds tests):

COL_NUM = Hash.new{ |h,alpha|
  offset = ?A - 1
  alpha.upcase!
  case alpha.size
    when 1
      h[alpha] = alpha[0] - offset
    when 2
      h[alpha] = ( alpha[0] - offset ) * 26 +
                 ( alpha[1] - offset )
  end
}