Smalltalk was certainly not the first attempt -- and -- the most versatile 
Smalltalk in this area was the first Smalltalk and also the smallest.


I personally think expressibility is not just semantic, but also syntactic. 
Many 
different styles of programming have been realized in Lisp, but "many to most" 
of them suffer from the tradeoffs of the uniform parentheses bound notation 
(there are positive aspects of this also because the uniformity does remove one 
kind of mystery). 


The scheme that Dan Ingalls devised for the later Smalltalks overlapped with 
Lisp's, because Dan wanted a programmer to be able to parse any Smalltalk 
program at sight, no matter how much the semantics had been extended. 
Similarly, 
there was a long debate about whether to put in "normal" precedence for the 
common arithmetic operators. The argument that won was based on the APL 
argument 
that if you have lots of operators then precedence just gets confusing, so just 
associate to the right or left. However, one of the big complaints about 
Smalltalk-80 from the culture that thinks parentheses are a good idea after 
"if", is that it has a non-standard precedence for + and * ....

A more interesting tradeoff perhaps is that between Tower of Babel and local 
high expressibility -- for example, when you decide to try lots of DSLs (as in 
STEPS). Each one has had the virtue of being very small and very clear about 
what is being expressed. At the meta level, the OMeta definitions of the syntax 
part are relatively small and relatively clear. But I think a big burden does 
get placed on the poor person from outside who is on the one hand presented 
with 
"not a lot of code that does do a lot", but they have to learn 4 or 5 languages 
to actually understand it.

People of my generation (50 years ago) were used to learning and using many 
syntaxes (e.g. one might learn as many as 20 or more machine code/assembler 
languages, plus 10 or more HLLs, both kinds with more variability in form and 
intent than today). Part of this could have stemmed from the high percentage of 
"math people" involved in computing back then -- part of that deal is learning 
to handle many kinds of mathematical notations, etc. 


Things seem different today for most programmers.

In any case, one of the things we learned from Smalltalk-72 is that even good 
language designers tend to create poor extensions during the heat of 
programming 
and debugging. And that an opportunity for cohesion in an extensible language 
is 
rarely seized. (Consider just how poor is the cohesion in a much smaller part 
of 
all this -- polymorphism -- even though it is of great benefit to everyone to 
have really strong (and few) polymorphisms.)

Cheers,

Alan




________________________________
From: Julian Leviston <jul...@leviston.net>
To: Fundamentals of New Computing <fonc@vpri.org>
Sent: Sat, June 4, 2011 10:44:07 AM
Subject: [fonc] languages

Hi,

Is a language I program in necessarily limiting in its expressibility?

Is there an optimum methodology of expressing algorithms (ie nomenclature)? Is 
there a good or bad way of expressing intent? Are there any intent languages in 
existence? Are there any pattern or algorithm languages? Is a programming 
language necessarily these two combined?

These are the questions I've been finding myself pondering lately.

For example, expressing object oriented concepts and patterns in C, while 
possible, proves rather "uncomfortable". Some things are almost impossible 
unless one "builds a world" inside C, but this is essentially building another 
language and using C as the meta-platform for this language, no? This would 
have 
to do with the fact that the design intent of the language didn't have this as 
its original intent, surely? Is there a way of patterning a language of 
programming such that it can extend itself infinitely, innately? Was smalltalk 
the first attempt at this? Does it fail by being too "large" in structural 
organisation?

In other words, would a "language" (or exploratory platform for programming) 
inherently require being "ridiculously simple" in terms of its structure in 
order to fully be able to represent any other "language" (or rather than 
language, simply more complicated structures) clearly?

Is Ometa an example of this?

Julian.
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