From: Jim Weirich <jweirich@...>
Date: 2002-04-18T08:53:50+09:00
Subject: Re: Ways methods return values

>>>>> "Sean" == Sean O'Dell <sean@celsoft.com> writes:

    Sean> I know in Ruby, the last evaluation is returned by a method
    Sean> and you can also explicitly "return" a value, but I was
    Sean> wondering if there was a way to do something I became
    Sean> accustomed to while programming in Pascal.

I would like to suggest an alternate style that you might find
readable and is easier to map into Ruby.

The Eiffel language also uses assignment to a (seemingly) local
variable to indicate the return value of a function.  But instead of
using the function name, the Eiffel variable is *always* named
"Result".  This makes post-conditions read very nicely, e.g. you could
assert things like "Result > 0" (pre and post conditions are a big
part of the Eiffel language).

In Ruby, I've gotten in the habit of using a variable named "result"
to hold the return type of a function.  The name of the variable makes
its intent clear to readers of the code.  The only thing I have to
remember is to make "result" the last line of my function.

For example, a factorial function would look like this:

  def factorial(n)
    result = 1
    (2..n).each { |i| result *= i }
    result
  end

Its just a suggestion.

-- 
-- Jim Weirich     jweirich@one.net    http://w3.one.net/~jweirich
---------------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct, 
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)