the OO metaphor

[Sean Hinde]

Hi Peter,

Not a comment on pureness really, just interested.

> I think this only results in even bigger problems. Especially 
> if I start defining
> unintuitive inheritance relationships between classes just to 
> avoid redefining
> methods!

The bit I struggle with is that it is all very nice designing a clean object
hierarchy with nicely encapsulated data, but by the time the system has
reached release 23 and every second requirement is orthogonal to the last
few this all falls apart and the system starts to resembles linguine.

FP/Erlang doesn't prevent this, but it seems to allow much more flexibility
to glue things together in different easily understood and maintainable ways
without breaking the underlying methodology in the ways you describe.

My observation of any number of decent sized custom IT systems/projects is
that there seems to be a maximum number of iterations they can go through
before (cost of change / unreliability) > (cost of throwing them away and
starting again).

Anything which delays this cutoff time is of enormous value as the
inevitable consequence is delay in providing new functionality with the
resulting negative impact on a business (not to mention the straight
financial and management cost). See press for details!

I guess this is little different for the company making widgets containing
software.

Rant over - I'm sure this is all done to death in
comp.lang.{functional || object} anyway.

- Sean




NOTICE AND DISCLAIMER:
This email (including attachments) is confidential.  If you have received
this email in error please notify the sender immediately and delete this
email from your system without copying or disseminating it or placing any
reliance upon its contents.  We cannot accept liability for any breaches of
confidence arising through use of email.  Any opinions expressed in this
email (including attachments) are those of the author and do not necessarily
reflect our opinions.  We will not accept responsibility for any commitments
made by our employees outside the scope of our business.  We do not warrant
the accuracy or completeness of such information.