Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!bloom-beacon!AWIUNI11.BITNET!V4110DAA
From: V4110DAA@AWIUNI11.BITNET (Gerhard Eckel)
Newsgroups: comp.lang.scheme
Subject: incremental definitions
Message-ID: <8905302120.aa01439@mintaka.lcs.mit.edu>
Date: 31 May 89 01:43:56 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
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In Digest #123 William Clinger <uoregon!will@beaver.cs.washington.edu> writes:

> Neither EVAL nor THE-ENVIRONMENT are part of Scheme, so the fact that XScheme
> happens to define procedures with those names that happen not to work the way
> someone expects has no bearing on whether it is a real Scheme system.

> Most people think it is better to think of incremental definitions as part
> of a programming environment instead of a language, since they are primarily
> used for debugging.  The programming environment obviously differs from one
> implementation to another, so code that depends on the programming environment
> is not portable.

   Is it  possible to  design an  object-oriented layer  which implements the
concepts of classes, inheritance and polymorphism in pure Scheme?   Something
like Scoops seems to be impossible  to build without functions like EVAL  and
THE-ENVIRONMENT.  In the case  of Scoops incremental definitons are  used for
much more than  debugging.  What  could I do  if I would  like to make Scoops
portable?  Am I completely missing the point?

Gerhard Eckel, v4110daa@awiuni11.bitnet