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From: kjx@comp.vuw.ac.nz (R James Noble)
Newsgroups: comp.lang.smalltalk
Subject: Smalltalk Implementation Summary
Message-ID: <1989Dec6.235311.12726@comp.vuw.ac.nz>
Date: 6 Dec 89 23:53:11 GMT
Sender: news@comp.vuw.ac.nz (News Admin)
Reply-To: kjx@comp.vuw.ac.nz (R James Noble)
Organization: Victoria University of Wellington, Wellington, New Zealand
Lines: 50


I have received several responses to my posting regarding Smalltalk
implementation. Thanks to all who replied. The general consensus was
as follows:-

a) Cascaded message sends.  Little Smalltalk is wrong in its
interpretation of this syntax: a b c; d should send c then d to the
result of (a b).

b) Blocks should be fully reentrant, and allow block temporaries.
Syntax: [ :a1 :a2 | t1 t2 | ... ]

c) Mutable literals. The most popular suggestion was to include classes
LiteralArray and LiteralString which would not include modification
messages .. no at:put: .  The second option was that mutable literals
were an important part of the language and should not be changed.

d) Multiple inheritance.  Standard Smalltalk does not include multiple
inheritance. It could be something worth including, especially if it
actually worked.

e) Class library. The core classes (Numbers, Collections) would need
to remain much the same. Graphics classes and the user interface are
heavily used by some people, however several other suggested that it
is getting obsolete, and so could be replaced. No-one seemed to care
about the internals of the Class hierarchy or the compiler, provided
the "feel" (mainly the external interfaces) of Smalltalk was retained.
The actual hierarchy of classes was considered less important than the
functionality and interface.

One strong opinion was that any system called Smalltalk should be
reasonably close to ParcPlace and/or the Blue Book. Unless a system is
at least as powerful as St-80 it should not be called a Smalltalk,
Smalltalk like, perhaps. It would need to support standard syntax,
possibly with changes b) and c) above, and the class library would
have to be reasonably close, perhaps as close as Digitalk (which
everyone seems to class as a "real" Smalltalk).

In reference to another question, I know of no Public Domain Smalltalk
implementation which would meet these criteria. (But would be happy to
be proved wrong!).




--
R James Noble
Graduate Student, Computer Science Department
Victoria University, Box 600, Wellington 1, New Zealand
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