Re: Object-relational impedence

From: S Perryman <>
Date: Wed, 12 Mar 2008 09:34:32 +0000
Message-ID: <fr883i$69e$>

JOG wrote:

>>On 2008-03-08 21:39:37 -0600, JOG <> said:

> A red herring as far as I'm concerned this Robert - after all RM is
> not an "inference engine" either. What I am questioning whether we
> need the concept of inheritance /whatsoever/. It does not exist in
> logic, it has no underlying theoretical justification, and is purely
> an ad hoc mechanism thrown together at xerox parc.

  1. Devised at the NCC in Norway, not Xerox PARC.
  2. Devised because of the influence of academic work on data types (Hoares' "record" types) , and noticing things having related properties/behaviours in simulation systems.

So not really ad-hoc (thought went into providing the scheme) .

> Is it not true that
> inheritance has lost favour over the years - composition is generally
> preferred, unless one is defining interfaces (and whether that should
> still be called "inheritance" is open to debate).

As a property acquisition/composition scheme, certainly. As a type substitutability mechanism, (sadly) no (Java, C# etc) .

Steven Perryman Received on Wed Mar 12 2008 - 10:34:32 CET

Original text of this message