From: gwtmp01@...
Date: 2006-04-03T01:08:37+09:00
Subject: Re: Typed Parameters


On Apr 2, 2006, at 11:26 AM, Robert Dober wrote:
> Well can you think of any tool that cannot be abused?

Well no, but I think the back and forth on this topic is
all about what should be considered 'abuse'.

So on one side we have folks who want to raise an exception when
an argument isn't an instance of String and on the other side we
have folks who just call to_s and let Ruby raise an exception if
the object doesn't implement to_s.

In either case you could codify the expectation as a pre-condition and
there are any number of ways to do that with Ruby. But having a
pre-condition mechanism doesn't answer the question:
What criteria should be used when designing pre-conditions?

Gary Wright