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Re: [Oberon] RiskOne ordered
by peter＠easthope.ca 14 May '21

14 May '21

Hi Wojciech, > I ordered production of two prototype RiskOne motherboards. If > anyone want to have those, it is the last minute to tell me so I can > possibly add more boards to the order. You need to do it today. The > cost will be $500 per board. Good news. I thought of asking about progress but better to refrain from bothering you. Please order one at my expense. No rush to receive it. As described earlier, it's an investment. Can convert 500 US to Canadian dollars and mail a paper cheque to your campus address. Is Interac used there? Might be Canada only. World Remit is international and I use it routinely. If you prefer another means of payment, just let me know. Thanks! ... P. -- tel: +1 604 670 0140 Bcc: peter at easthope. ca

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PO 2013 allows one to "override" predefined procedures and functions
by Andreas Pirklbauer 14 May '21

14 May '21

Wojtek, The run time behaviour of this “feature” is to simply override the predefined identifier, which then is no longer available in the current scope. So no crash. One can even override things like INTEGER, etc. Actually, the compiler itself does some overriding in this way, namely with the three procedures ORG.ADC, ORG.SBC, ORB.UML. Inside these three procedures the corresponding predefined identifier (ADC, SBC or UML) is of course not available. To disallow this kind of “overrriding” in the compiler, one could for example: 1. Rename ORG.ADC, ORG.SBC, ORB.UML to ORG.Adc, ORG.Sbc, ORB.Uml 2. Adapt ORP.StandFunc accordingly to use the new procedure names 3. Adapt ORB.NewObj such that it now also checks the predefined identifiers as follows: x := universe; WHILE (x # NIL) & (x.name # id) DO x := x.next END ; IF x = NIL THEN (*...ok...*) ELSE ORS.Mark("predefined identifier”) END to arrive at something along the lines of: PROCEDURE NewObj*(VAR obj: Object; id: ORS.Ident; class: INTEGER); (*insert new Object with name id*) VAR new, x: Object; BEGIN x := universe.next; WHILE (x # NIL) & (x.name # id) DO x := x.next END ; IF x = NIL THEN x := topScope; WHILE (x.next # NIL) & (x.next.name # id) DO x := x.next END ; IF x.next = NIL THEN NEW(new); new.name := id; new.class := class; new.next := NIL; new.rdo := FALSE; new.dsc := NIL; x.next := new; obj := new ELSE obj := x.next; ORS.Mark("mult def") END ELSE ORS.Mark("predefined identifier") END END NewObj; PS: When doing this, the impact on the compiler’s performance is about 5-10%. -ap > Andreas: > > what a great feature. It could be really useful in the hands of a creative programmer. I am wondering, what would be the run time behavior of this feature. A crash? > > How did you find this feature? Would be good to get rid of it. > > Wojtek ________________________________________ From: Oberon [ oberon-bounces at lists.inf.ethz.ch] on behalf of Andreas Pirklbauer [andreas_pirklbauer at yahoo.com ] Sent: Friday, May 14, 2021 9:29 AM To: Oberon List Subject: [EXT] [Oberon] PO 2013 allows one to "override" predefined procedures and functions Has anyone noticed that the PO 2013 allows the programmer to “overrride” predefined procedures and functions, e.g., MODULE M; VAR INC: CHAR; i: INTEGER; BEGIN INC := "a”; INC(i) (*not a procedure*) END M. This should not be allowed..

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PO 2013 allows one to "override" predefined procedures and functions
by Andreas Pirklbauer 14 May '21

14 May '21

Has anyone noticed that the PO 2013 allows the programmer to “overrride” predefined procedures and functions, e.g., MODULE M; VAR INC: CHAR; i: INTEGER; BEGIN INC := "a”; INC(i) (*not a procedure*) END M. This should not be allowed..

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Should hidden re-imports be able to coexist with identifiers
by Andreas Pirklbauer 14 May '21

14 May '21

> […] A similar situation occurs, when hidden re-imports clash with alias names. Thanks to all for the various emails on this topic. Below is a fix for this topic as well: One simply skips re-imports (~obj.rdo) in NewObj, thisObj *and* now also in ThisModule, and simultaneously allows re-imports and aliases to co-exist: PROCEDURE NewObj*(VAR obj: Object; id: ORS.Ident; class: INTEGER); (*insert new Object with name id*) VAR new, x: Object; BEGIN x := topScope; WHILE (x.next # NIL) & ((x.next.name # id) OR (x.next.class = Mod) & ~x.next.rdo) DO x := x.next END ; IF x.next = NIL THEN NEW(new); new.name := id; new.class := class; new.next := NIL; new.rdo := FALSE; new.dsc := NIL; x.next := new; obj := new ELSE obj := x.next; ORS.Mark("mult def") END END NewObj; PROCEDURE thisObj*(): Object; VAR s, x: Object; BEGIN s := topScope; REPEAT x := s.next; WHILE (x # NIL) & ((x.name # ORS.id) OR (x.class = Mod) & ~x.rdo) DO x := x.next END ; s := s.dsc UNTIL (x # NIL) OR (s = NIL); RETURN x END thisObj; PROCEDURE ThisModule(name, orgname: ORS.Ident; decl: BOOLEAN; key: LONGINT): Object; VAR mod: Module; obj, obj1: Object; BEGIN obj1 := topScope; obj := obj1.next; (*search for module*) WHILE (obj # NIL) & (obj(Module).orgname # orgname) DO obj1 := obj; obj := obj1.next END ; IF obj = NIL THEN (*new module, search for alias*) obj := topScope.next; WHILE (obj # NIL) & ((obj.name # name) OR decl & ~obj.rdo) DO obj := obj.next END ; IF (obj # NIL) & obj.rdo & decl THEN ORS.Mark("mult def") ELSE (*insert new module*) NEW(mod); mod.class := Mod; mod.rdo := FALSE; mod.name := name; mod.orgname := orgname; mod.val := key; mod.lev := nofmod; INC(nofmod); mod.type := noType; mod.dsc := NIL; mod.next := NIL; obj1.next := mod; obj := mod END ELSIF decl THEN (*module already present, explicit import by declaration*) IF obj.rdo THEN ORS.Mark("mult def") ELSE ORS.Mark("invalid import order") END END ; RETURN obj END ThisModule; With that fix, the only remaining restriction in the PO 2013 compiler relative to Luca’s ‘oberonc’ compiler is the "invalid import order” restruction. And that one is also doable, but would be a tick more complex (merging of lists of type objects in mod.dsc). Worth the trouble? -ap - - - - > I agree. The above example works in oberonc <https://github.com/lboasso/oberonc> > (once you make use of the import M1 and global variable M0 since unused identifiers > will be an > error in oberonc). At this point I am more and more convinced that the > algorithm from* Griesemer R. On the Linearization of Graphs and Writing Symbol > File* is the best approach while still being relatively simple to implement. > This corner case and many more are handled and it removes the import order > limitation of Wirth's compiler. - - - - - > > On Thu, May 13, 2021 at 9:33 AM Andreas Pirklbauer < >> andreas_pirklbauer at yahoo.com> wrote: > > The following reports a “mult def” error in PO 2013 when compiling M2 > > > > MODULE M0; > > TYPE T0* = RECORD i: INTEGER END ; > > END M0. > > > > MODULE M1; > > IMPORT M0; > > TYPE T1* = RECORD (M0.T0) j: INTEGER END ; > > END M1. > > > > MODULE M2; > > IMPORT M1; (*re-imports M0.T0*) > > VAR M0: INTEGER; (* <--- "mult def” error message*) > > END M2. > > > > In PO2013 this error is reported because the symbol table headed > > by topScope *also* contains the re-imported module M0 (which is > > a bit unfortunate) -- but ORB.NewObj does not check that fact. > > > > I my mind, M2 should compile with no error message. i.e. hidden > > re-imports should be able to coexist with regular identifiers (since > > one cannot refer to re-imported objects by name anyway). > > > > Comments? > >

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Should hidden re-imports be able to coexist with identifiers
by Andreas Pirklbauer 13 May '21

13 May '21

Hi Luca, Yes, you’re right, it works in oberonc of course.. because your compiler does not “merge” the module list with the list of identifiers as NW did in PO2013. You use module tables, just like Griesemer's algorithm. But now I just realized that the issue described below in fact has a trival fix also in PO 2013, namely to simply check (in ORB.NewObj and in ORB.thisObj) whether an object x in the topScope is in fact a re-imported module - and simply skip it if it is one. PS: A similar situation occurs, when hidden re-imports clash with alias names (they shouldn’t clash). With the change below it’s easy to fix to in ThisModule (see below). PS2: But the import order restriction would still remain. Andreas PROCEDURE NewObj*(VAR obj: Object; id: ORS.Ident; class: INTEGER); (*insert new Object with name id*) VAR new, x: Object; found: BOOLEAN; BEGIN x := topScope; found := FALSE; WHILE ~found & (x.next # NIL) DO IF ((x.next.class # Mod) OR x.next.rdo) & (x.next.name = id) THEN found := TRUE ELSE x := x.next END END ; IF x.next = NIL THEN NEW(new); new.name := id; new.class := class; new.next := NIL; new.rdo := FALSE; new.dsc := NIL; x.next := new; obj := new ELSE obj := x.next; ORS.Mark("mult def") END END NewObj; PROCEDURE thisObj*(): Object; VAR s, x: Object; found: BOOLEAN; BEGIN s := topScope; REPEAT x := s.next; found := FALSE; WHILE ~found & (x # NIL) DO IF ((x.class # Mod) OR x.rdo) & (x.name = ORS.id) THEN found := TRUE ELSE x := x.next END END ; s := s.dsc UNTIL (x # NIL) OR (s = NIL); RETURN x END thisObj; PROCEDURE thisimport*(mod: Object): Object; VAR obj: Object; BEGIN IF mod.rdo & (mod.name[0] # 0X) THEN obj := mod.dsc; WHILE (obj # NIL) & (obj.name # ORS.id) DO obj := obj.next END ELSE obj := NIL END ; RETURN obj END thisimport; PROCEDURE ThisModule(name, orgname: ORS.Ident; decl: BOOLEAN; key: LONGINT): Object; VAR mod: Module; obj, obj1: Object; BEGIN obj1 := topScope; obj := obj1.next; (*search for module*) WHILE (obj # NIL) & (obj(Module).orgname # orgname) DO obj1 := obj; obj := obj1.next END ; IF obj = NIL THEN (*new module, search for alias*) obj := topScope.next; WHILE (obj # NIL) & (obj.name # name) DO obj := obj.next END ; IF (obj # NIL) & decl & obj.rdo THEN ORS.Mark("mult def") ELSE (*insert new module*) NEW(mod); mod.class := Mod; mod.rdo := FALSE; mod.name := name; mod.orgname := orgname; mod.val := key; mod.lev := nofmod; INC(nofmod); mod.type := noType; mod.dsc := NIL; mod.next := NIL; obj1.next := mod; obj := mod END ELSIF decl THEN (*module already present, explicit import by declaration*) IF obj.rdo THEN ORS.Mark("mult def") ELSE ORS.Mark("invalid import order") END END ; RETURN obj END ThisModule; Andreas - - - - > I agree. The above example works in oberonc <https://github.com/lboasso/oberonc> > (once you make use of the import M1 and global variable M0 since unused identifiers > will be an > error in oberonc). At this point I am more and more convinced that the > algorithm from* Griesemer R. On the Linearization of Graphs and Writing Symbol > File* is the best approach while still being relatively simple to implement. > This corner case and many more are handled and it removes the import order > limitation of Wirth's compiler. - - - - - > > On Thu, May 13, 2021 at 9:33 AM Andreas Pirklbauer < >> andreas_pirklbauer at yahoo.com> wrote: > > The following reports a “mult def” error in PO 2013 when compiling M2 > > > > MODULE M0; > > TYPE T0* = RECORD i: INTEGER END ; > > END M0. > > > > MODULE M1; > > IMPORT M0; > > TYPE T1* = RECORD (M0.T0) j: INTEGER END ; > > END M1. > > > > MODULE M2; > > IMPORT M1; (*re-imports M0.T0*) > > VAR M0: INTEGER; (* <--- "mult def” error message*) > > END M2. > > > > In PO2013 this error is reported because the symbol table headed > > by topScope *also* contains the re-imported module M0 (which is > > a bit unfortunate) -- but ORB.NewObj does not check that fact. > > > > I my mind, M2 should compile with no error message. i.e. hidden > > re-imports should be able to coexist with regular identifiers (since > > one cannot refer to re-imported objects by name anyway). > > > > Comments? > >

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Should hidden re-imports be able to coexist with identifiers
by Andreas Pirklbauer 13 May '21

13 May '21

The following reports a “mult def” error in PO 2013 when compiling M2 MODULE M0; TYPE T0* = RECORD i: INTEGER END ; END M0. MODULE M1; IMPORT M0; TYPE T1* = RECORD (M0.T0) j: INTEGER END ; END M1. MODULE M2; IMPORT M1; (*re-imports M0.T0*) VAR M0: INTEGER; (* <--- "mult def” error message*) END M2. In PO2013 this error is reported because the symbol table headed by topScope *also* contains the re-imported module M0 (which is a bit unfortunate) -- but ORB.NewObj does not check that fact. I my mind, M2 should compile with no error message. i.e. hidden re-imports should be able to coexist with regular identifiers (since one cannot refer to re-imported objects by name anyway). Comments?

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Email; was Streams.
by peter＠easthope.ca 13 May '21

13 May '21

From: Liam Proven <lproven(a)gmail.com> Date: Thu, 13 May 2021 14:26:13 +0200 > I personally use Thunderbird, and this enables offline replies, > composition, editing etc. You only need to go online to send and > receive. An old topic repeated too often; IMAP is also available in A2 and POP3 is in Oberon. Messages can be retrieved by POP3. Messages can be read offline. Replies can be composed offline. Connect and send by SMTP. =8~) The discussion always reminds me of a comment by a developer of molecular graphics software. Paraphrasing: one tends to have more confidence in software which the developer is willing to use. Generalized slightly, applicable here: one tends to have more confidence in software used by people claiming it to be good software. =8~) Regards, ... P.L. -- tel: +1 604 670 0140 Bcc: peter at easthope. ca

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Re (2): Re (2): Re (2): Streams.
by peter＠easthope.ca 13 May '21

13 May '21

From: eas lab <lab.eas(a)gmail.com> Date: Tue, 4 May 2021 00:18:55 -0400 > Can aos do: > list the 22 most recentcy-ordered > including <dotted files> in /tmp ? > eg.*nix: ls -ta /tmp | head -22 Your *nix system should be firewalled. If not install Shorewall. In /etc/inetd.conf comment out #telnet stream tcp nowait telnetd /usr/sbin/tcpd /usr/sbin/in.telnetd and add this. telnet stream tcp nowait eas /usr/sbin/tcpd /usr/sbin/telnetd -E bin/bash In the Oberon subsystem, a console is opened without a password. Desktops.OpenDoc telnet://localhost There do the linux command. ls -ta /tmp | head -22 ls -ta /path/to/any/directory | head -22 Etc. A2 also has Tools > Serial Terminal which should connect to localhost and accept commands. Regards, ... P.L. -- tel: +1 604 670 0140 Bcc: peter at easthope. ca

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Re (2): Re (2): Re (2): Re (2): Streams.
by peter＠easthope.ca 13 May '21

13 May '21

> P.E's reply to my query makes no sence ? I suggested a means to have a host console in A2. Also in the Oberon subsystem. Ref. here. https://en.wikibooks.org/wiki/Oberon/A2#User_Level_Applications In the host console you can execute any linux command. Then copy the results to an Oberon viewer using MR+MM. Or save the host result to a file and open the file in the Oberon system. That's your objective? No? ... P. -- tel: +1 604 670 0140 Bcc: peter at easthope. ca

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Michael Franz receives 2020 ACM Chuck Thacker Breakthrough Award
by Andreas Pirklbauer 10 May '21

10 May '21

Just FYI: https://www.acm.org/media-center/2021/april/thacker-award-2020 PS: Michael was my assistant in the course Informatik 3/4 given by Niklaus Wirth in the late 80s. He also showed me many tricks in compiler design.. - - - - - - ACM Chuck Thacker Breakthrough Award Goes to Innovator Who Transformed Web Applications UC Irvine's Michael Franz Made Just-In-Time Compilation Practical for Billions of Web Users Daily New York, NY, April 28, 2021 – ACM, the Association for Computing Machinery, today announced that Michael Franz of the University of California, Irvine is the recipient of the ACM Charles P. “Chuck” Thacker Breakthrough in Computing Award. Franz is recognized for the development of just-in-time compilation techniques that enable fast and feature-rich web services on the internet. Every day, millions of people around the world use online applications such as Gmail and Facebook. These web applications would not have been possible without the groundbreaking compilation technique Franz developed in the mid-1990s. Beginning with the PhD thesis he completed in 1994, Franz has been exploring the use of just-in-time (JIT) dynamic compilation and optimization, focusing not only on static languages such as Java, but also on dynamically-typed languages. Initially such dynamic languages were primarily used in research and academic settings, but that changed when JavaScript was adopted for creating web services. JavaScript enabled the creation of websites that had application-like behavior, rather than the more static websites enabled by HTML. JavaScript, like other dynamic languages, was initially interpreted, and that led to poor performance. By inventing a new compilation technique, developing a JIT compiler for JavaScript based on this new technique, and then collaborating with Mozilla to incorporate it into the Firefox browser, Franz enabled massive growth in the use of JavaScript, now one of the world’s most heavily used programming languages. “We all use web-based applications every day and they are now so prevalent that we often forget how revolutionary they were when they were first introduced,” said ACM President Gabriele Kotsis. “Whether we’re connecting with friends or colleagues on a social media platform, preparing our taxes using online software, or booking an accommodation at a hotel, we are using a web-based application. Michael Franz’s work certainly fits the Thacker Award’s criteria for ‘leapfrog contributions to computing ideas and technologies.’ Franz displayed foresight in working with Mozilla to implement his ideas on their browser and in making his technology open source so that it could be continually refined and adapted by developers worldwide.” The idea of JIT dynamic compilation goes back decades and was initially used for a variety of statically-typed-languages. In the 1970s, researchers at the Xerox Palo Alto Research Center used JIT compilation for Smalltalk, a dynamically-typed language. In the 1980s, researchers at Stanford and Sun explored the use of JITs for Self, a dynamically typed, prototype-based language similar to JavaScript. Franz made several important contributions beyond this earlier work that greatly increased the practicality of JIT compilation. First, rather than optimizing entire functions, he introduced a technique that optimizes only the loops of a program, using a structure called a “trace tree” to represent alternative paths through a loop that are discovered and subsequently translated incrementally. Second, Franz developed a JIT compiler that could be applied in a variety of settings, including those with more limited CPU or memory resources. With these techniques, Franz’s JIT compiler could often achieve performance improvements of 5-10x on JavaScript, which was critical to its wide-ranging adoption and the transformation of web applications. Most websites today use JavaScript, and all browsers include a JavaScript execution engine. Franz’s technology helped make this transformation possible. “Microsoft is proud to fund the Breakthrough in Computing Award, named after Chuck Thacker, one of the computing field’s true visionaries,” said Eric Horvitz, Microsoft’s Chief Scientific Officer. “Chuck had a magical ability to transform over-the-horizon computing dreams into world-changing realities. Michael Franz’s work on just-in-time compilation is a great choice for the Breakthrough in Computing honor. His work has been transformative, enabling today’s rich web experiences by allowing websites to execute sophisticated, interactive programs nearly instantaneously. Michael Franz’s insights, and his successful application of those insights, have had tremendous real-world impact.” Biographical Background Michael Franz is a Chancellor's Professor in the Department of Computer Science at the University of California (UC), Irvine, where he also directs the Secure Systems and Software Laboratory. His current research emphasis is in software systems, particularly focusing on compiler, virtual machine, and related system-level techniques for making software safer, or faster, or both. Franz received a Doctor of Technical Sciences degree in Computer Science and a Diplomingenieur, Informatik-Ing. ETH degree, both from the Swiss Federal Institute of Technology (ETH Zurich). His honors include receiving a Humboldt Research Award from the Alexander von Humboldt Foundation, a National Science Foundation CAREER Award, an IEEE Computer Society Technical Achievement Award, and a Distinguished Mid-Career Faculty Award for Research from the University of California, Irvine. Franz is a Fellow of ACM, the Institute of Electrical and Electronics Engineers (IEEE), the American Association for the Advancement of Science (AAAS), and the International Federation for Information Processing (IFIP). About the ACM Charles P. "Chuck" Thacker Breakthrough in Computing Award The ACM Breakthrough Award celebrates Thacker's pioneering contributions in computing and his long-term inspirational mentorship of generations of computer scientists. The award recognizes individuals or groups with the same out-of-the-box thinking and “can-do” approach to solving the unsolved that Thacker exhibited. The award is accompanied by a prize of $100,000 and is presented at the annual ACM Awards Banquet. Recipients are expected to give the ACM Breakthrough Lecture at a major ACM conference of their choosing during the year following the announcement. Financial support of the ACM Breakthrough Award is provided by Microsoft. About ACM ACM, the Association for Computing Machinery, is the world's largest educational and scientific computing society, uniting educators, researchers and professionals to inspire dialogue, share resources and address the field's challenges. ACM strengthens the computing profession's collective voice through strong leadership, promotion of the highest standards, and recognition of technical excellence. ACM supports the professional growth of its members by providing opportunities for life-long learning, career development, and professional networking.

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