From: wsdng@... (=?ISO-8859-1?Q?Sascha_D=F6rdelmann?=)
Date: 2003-07-17T06:52:08+09:00
Subject: Re: How to reduce Ruby runtime error?

Xiangrong Fang <xrfang@hotmail.com> wrote:
> I repeat: Thanks for all the suggestion regarding unit test and
> exceptions. Acutally I have already used if/then, or rescue to catch
> these runtimes. What I am complaining is that if I have to always do
> this in ruby programming, I might be losing all the productivity I
> gained from the excellent language.

You won't lose your productivity.

The topic has been broadly discussed in comp.lang.*. Do a search in
groups.google.com on "Why dynamic typing" and "Newbie: argument
checking in Smalltalk"
  http://groups.google.com/groups?q=Why+dynamic+typing
  http://groups.google.com/groups?q=Newbie+argument+checking+Smalltalk

My own opinion is, that your own suggestion about nils behaving like
various other objects won't lead to a robust program. (Maybe I still
don't get what you meant by robust? ;-)

A robust program won't ignore errors. It will detect them and behave
in a deterministic way. Unit tests are the best way towards robust
programs I know of. The second best is to use some assertion concept
based on exceptions. Start with some basic exception handling and
focus on error detection instead of error handling. After reducing the
total amount of errors you will easily find the places where error
handling makes sense and where it does not.

Cheers
Sascha