From: Brian Candler <B.Candler@...>
Date: 2008-08-27T17:13:52+09:00
Subject: Re: Deaf Grandma

> if response == (response.upcase and "BYE")

That doesn't make sense. response.upcase is always true (not nil or false),
so (response.upcase and "BYE") is just the same as "BYE". Try it in irb to
convince yourself.

There's also no need to initialise response at the start of the program.
Apart from that your code looks fine. Here is an alternative version, using
regular expressions and 'next' and 'break' flow control.

  puts "Hey Sonny! It's your lovely Grandmother! How are yeah?"

  bye = 0
  while response = gets
    case response
    when /^BYE$/
      bye += 1
      break if bye >= 3
      puts "Hmmm... I would prefer..."
      next
    when /[a-z]/
      puts "Huh?! I CAN'T HEAR YOU!"
    when /[A-Z]/
      puts "NO! NOT SINCE #{1930+rand(21)}!"
    end
    bye = 0
  end

(The original problem didn't say what to do if you said a blank line to
Granny, or a line which contained no alphabetic characters. In this program
she just ignores you, but still resets the bye counter to zero. This is easy
to change.)

Note there is a subtlety with "gets". If you ever modify this program to
take arguments on the command line, "gets" will behave strangely, because it
will treat the command line arguments as filenames to read. For example,

   ruby granny.rb 1930 1950

will try to read responses from files called "1930" and "1950", instead of
from stdin. To make sure you're always using stdin, you're better off
writing

  while response = $stdin.gets

(This magic Kernel#gets is a bit of ugliness inherited from Perl. Personally
I find it trips me up rather than being helpful, which is why I mention it
here :-)

Regards,

Brian.

P.S. At some point you may wish to rewrite this code in a way which can
easily be unit-tested - and which lets you talk to multiple grannies at the
same time :-)