From: jwesley <justin.w.smith@...>
Date: 2005-12-22T23:07:49+09:00
Subject: Re: String > Integer Conversion Problem

I disagree that this particular use of an exception would be a no-no in
Java.  Inability to parse input is justifiably an "exceptional" case.
And the handling of that exceptional case is also appropriate.

The big "no-no" about exception usage is true for any language: "Don't
use exceptions for flow control".

The following code is "wrong" for various reasons as well as violating
the "axiom" above:

begin
  # display 1 through 10
  i = 0
  while true
    unless i > 10
      puts i
    else
      raise "End o' the line"
    end
    i += 1
  end
rescue
end

Ruby provides enough mechanisms for "controlling the flow" that using
exceptions for "normal" conditions is definitely poor style, if not
worse.

BTW "continuations" (related to exceptions) are a fairly powerful tool
to handle the times when strange flow control might be needed.