Re: Pre-condition vs. Post-condition

[jls@rutabaga.Rational.COM (Jim Showalter)]

>Reaching the end-of-file or trying to POP off an
>empty stack are NOT exceptional conditions.

How to you justify this? Exceptions protect clients from incorrect
algorithmic implementation. If a client attempts to read past end of
file or pop past empty stack, it should be notified of the fact,
since the client is in error. Other mechanisms (e.g. status flags)
must be checked by the client to be effective (polling model), whereas
exceptions cannot be overlooked (interrupt model). Thus, exceptions
are more fail-safe.

You also say that you don't think an exception should ever be raised
after a system is delivered. I don't see how you can meet this constraint.
For example, consider interaction with a user, a la Enumeration_Io.
If the user enters bogus data--which you have no control over from
within the program--an exception will be raised. This is not only
unavoidable, but seems desirable to me.
--
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