Talk:Clascal

Moving comments from article to discussion page

I would like to take the liberty of moving the recent comments by Anonymous 216.184.9.5 in the Clascal article to its talk page, because by their nature they seem to be more in the line of a discussion. --Ziusudra 02:08, 24 June 2007 (UTC)

Comments by Anonymous 216.184.9.5

I've never heard of the Apple POS division being officially called the "Lisa Division".

Clascal was based on LisaPascal which was created by SVS of Silicon Valley from its SVS Pascal. SVS Pascal was based on the ETH Pascal and not UCSD Pascal.

Clascal was also revised, at least from a design perspective, in 1984/1985 to be called Clascal-85. This design was never implemented AFAIK.

—Preceding unsigned comment added by 216.184.9.5 (talk • contribs)

Responses to Comments by Anonymous 216.184.9.5

Lisa Division

I'm not sure what it takes to make a division name "offical", but the name change was annnounced at a divisional meeting. Since the article is about Clascal, here is a facsimile of the title page of the Clascal Beta Draft manual, dated 30 Sep 1983:

An Introduction to Clascal
Beta Draft
Technical Review Copy

Susan Keohan
Pubs/Training Department
Lisa Division
Apple Computer, Inc.
extension 2707

Pedigree of Lisa Pascal/Clascal

By definition all Pascal implementations ultimately hark back to Nicholas Wirth and ETH (Eidgenössische Technische Hochschule Zürich) Pascal; it is the basis of the ANSI standard. However, when the third-party company SVS (Silicon Valley Software) was engaged to produce Lisa Pascal for Apple in 1981, their assignment was to produce a compiler which was backwards-compatible with Apple Pascal. All of the Lisa OS code up to that time had been written in Apple II/III (UCSD) Pascal. SVS's main contribution was the code generator, which was a compiler, rather than an interpreter.

• Craig,David. "A Review of Apple's Lisa Pascal," October 9, 1988. Available online at Dr. Dobbs Archive:

“ Originally begun in early 1980 as a port from Apple // Pascal, Lisa Pascal evolved into a very powerful compiler.... Lisa Pascal is a superset of UCSD Pascal and initially resembled Apple /// Pascal 2.0....Since the Lisa Pascal Compiler began life as an Apple // compiler it can compile source code from either the // or ///.... The Lisa Pascal Compiler generates I-code (intermediate code) which is actually only standard UCSD Pascal P-code. The Code Generator takes the compiler's I-code file and produces 68000 object code. ”

"Clascal-85"

What Anon appears to be referring to is what became Object Pascal:

• Allen, Dan. "The Macintosh Programmer's Workshop: Apple's internal Macintosh development system is available to the rest of us." "Dr. Dobb's Journal," July 22, 2001. Available online at [1].

“ MPW Pascal is a descendant of Lisa Pascal and conforms closely to the ANSI standard for Pascal. Its enhancements to standard Pascal are major and significant and require a bit of explanation. Silicon Valley Software (SVS) originally wrote Lisa Pascal for Apple in 1981, although Apple has maintained it for years now. It supported Units, a method of separate compilation that provides an Interface as well as an Implementation section for each module of code, thus providing similar facilities to Modula-2.... An early version of object-oriented programming was supported as the language further evolved into a language called Clascal. Clascal began in 1983, when Larry Tesler (formerly of Xerox PARC) asked Chris Franklin to implement classes. It was later enhanced by Al Hoffman and then by Ira Ruben. Early in 1985, a team including Larry Tesler and Nikolaus Wirth created Object Pascal, a superset of Pascal and the successor to Clascal. Object Pascal also supports the concepts of objects, classes, and inheritance but in a simpler and clearer way than does Clascal. Ken Doyle finished things up by writing the Object Pascal extensions to the MPW Pascal compiler. ”

--Ziusudra 02:08, 24 June 2007 (UTC)