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From: utzoo!decvax!harpo!floyd!cmcl2!lipkis	[thread overview]
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A few notes about NYU Ada/Ed:

Ada/Ed is indeed very slow. This is by design, and has nothing
to do with the use of SETL per se. In fact SETL running code of
a PASCAL semantic level runs only 5-10 times slower than PASCAL,
even faster in some favourable cases.

The point about Ada/Ed is that the semantic level of the interpretor
is very high. The actual code of the interpretor is more akin to
a formal semantic definition than a conventional interpretor, and
indeed Ada/Ed is best regarded as an executable formal definition
of Ada, rather than a programming tool. For example, while loops
are executed by duplicating copies of the code, and code generation
for expressions is done essentially dynamically by walking the
expression tree at run time. The entire object of the development
is to produce a system with highly readable code (copies of the
listing of the interpretor are available from NYU Ada Project,
Courant Inst., 251 Mercer St., N.Y.C., NY 10012 at a cost of $25 if
you want to see for yourself).

Despite this approach, it is possible to use Ada/Ed for familiarization
with Ada, and the fact that it has been officially validated is a
useful guarantee that someone using Ada/Ed is familiarizing themselves
with a reasonably accurate implementation of the language.

We have so far strenuously avoided the slightest hint of efficiency,
and the whole project has been developed under the conceptual guideline
that "slow is beautiful". However, Ada/Ed is in wide use as a training
and familiarization tool at several hundred sites, and it appears that
there will be an appreciable window in which it will be the only full
Ada system available for many machines. Consequently, it is at this
stage useful to work on improving its efficiency, and our current
project funding includes resources for this purpose. We expect
that a version of Ada/Ed will be released later this year with
very great execution speed improvements.

Robert Dewar		(reply to cmcl2!acf2!dewar)
NYU Ada Project
Courant Inst. of Math. Sci.
251 Mercer St.
New York, N.Y.   10012

                 reply	other threads:[~1983-05-13  0:56 UTC|newest]

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