January 2016 - Oberon - mailman3.inf.ethz.ch

Re (3): Input.Timer in Native Oberon
by peter＠easthope.ca 30 Jan '16

30 Jan '16

Joerg, Thanks. I should have read your reply before sending another. ... Lyall E. -- 123456789 123456789 123456789 123456789 123456789 123456789 123456789 12 Tel +1 360 639 0202 http://easthope.ca/Peter.html Bcc: peter at easthope. ca

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Re (2): Input.Timer in Native Oberon
by peter＠easthope.ca 30 Jan '16

30 Jan '16

From: Chris Burrows <chris(a)cfbsoftware.com>, Fri, 29 Jan 2016 08:04:10 +1030 > ... values 100 and 12 have a certain significance in this context? Serial port speed 1200 appears in a few places. Obviously no connection. Sorry but 100 and 12 are magic numbers. 2% docked from grade for each. If i is too large, the "key mouse" will over-respond. One click and the arrow will be at the edge of the display. If i is too small "key mouse" will under-respond. In the extant calculation of i, if powers of 10 are considered in the divisor, 10 is too small and 1000 is too large. So "100" is OK? The "12"? Who knows, but see following. > PixelCount = 1024 * 768; (* Better than PixelCount = 786432; *) You might be astonished at the number of students in a first year class who don't recognize "1024 * 768". A helpful reference wouldn't be a crime. PixelCount = 1024 * 768; (* https://en.wikipedia.org/wiki/Display_resolution *) > ... better to let the code speak for itself. Absolutely! I gave names to the magic numbers. Initialized counter1 right after counter0. The outmost IF statement was in reverse chronological order. Reversed it for clarity. Also, when kpmap * {0..2, 4, 6, 8..10} = {}, incrementing i and checking the four displacements is pointless. MODULE Input; ... CONST TimeUnit* = 1000; (** portable, but VAR on other ports *) (** timer ticks per second (platform dependent). *) KPpollinterval = TimeUnit DIV 100; (* KP = keypad. Used as pseudo mouse. *) KPdivisor = 8; (* counter0 per pixel. *) KPspeedMax = 100; (* Maximal counter0. *) ... PROCEDURE *Timer; VAR i: INTEGER; BEGIN IF counter1 < KPpollinterval THEN INC(counter1) ELSE counter1 := 0; IF kpmap * {0..2, 4, 6, 8..10} = {} THEN counter0 := 0 ELSE IF counter0 < KPspeedMax THEN INC(counter0) END; i := counter0 DIV KPdivisor + 1; IF kpmap * {0,4,8} # {} THEN DEC(kdx, i) END; IF kpmap * {0,1,2} # {} THEN DEC(kdy, i) END; IF kpmap * {2,6,10} # {} THEN INC(kdx, i) END; IF kpmap * {8,9,10} # {} THEN INC(kdy, i) END END END END Timer; BEGIN ... counter0 := 0; counter1 := 0; ... END Input. How's that? Incidentally, Timer is not an enlightening name for the procedure. Too general. It does more than time. KPpointer? KPcontroller? Many names could say more than "Timer". Regards, ... Lyall E. -- 123456789 123456789 123456789 123456789 123456789 123456789 123456789 12 Tel +1 360 639 0202 http://easthope.ca/Peter.html Bcc: peter at easthope. ca

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Re: [Oberon] Oberon program compilation, linking and execution on Windows AND Linux and everything else.
by scrutinizer 30 Jan '16

30 Jan '16

Hi Try this Oberon programming example: http://www.modulaware.com/mdlt/?n=96 Runs everywhere — without download/install anything. Loads the Oberon source files, compiles and executes "˙sǝop ʎpoqǝɯos ʇɐɥʇ ǝɹns ǝʞɐɯ oʇ puɐ — ʇı sǝɔıʇou ʎpoqʎuɐ ɟı ǝǝs oʇ punoɹɐ ƃuıʞool 'ƃuıssɐd uı 'ʇuǝɯıɹǝdxǝ uɐ sɐ :uıs llɐɯs ɐ uı [ƃuıƃlnpuı] sɐ ʇsnɾ — — [5981] ǝɥɔszʇǝıu ɥɔıɹpǝıɹɟ ʎq "slopı ǝɥʇ ɟo ʇɥƃılıʍʇ" To extension of the template for dynamic module loading is — left as an exercise. )) happy WE Date: Fri, 29 Jan 2016 22:48:57 +0530 From: Srinivas Nayak <sinu.nayak2001(a)gmail.com> To: ETH Oberon and related systems <oberon(a)lists.inf.ethz.ch> Subject: [Oberon] Oberon program compilation, linking and execution on Windows or Linux. Dear All, Normally a C program when compiled, produces object file. Object file contains machine level code and symbol table. Object files (along with library object files) are linked using a linker to generate an executable file. Finally loader takes care of loading the shared libraries and executing the program. How these things happen for Oberon language programs on Windows or Linux? Any document describes this in detail (mostly what happens after finishing typing a Oberon Program to program execution start)? With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

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(no subject)
by None 30 Jan '16

30 Jan '16

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Re: [Oberon] Use of resources.
by Pablo Cayuela 30 Jan '16

30 Jan '16

On Mon, Jan 11, 2016 at 6:33 PM, Lars O <noreply(a)z505.com> wrote: > ... To prove a program correct, such as Microsoft Windows and all it's dll's, would require super amounts of time, which is >not possible in this particular universe... >If we develop the ability to live for 1000 years it may be possible to prove an entire operating system correct,... >Correctness proving only works on trivial Toy programs that have an IN and OUT, like an old standard pascal program that just calculates things and finishes... > You can only prove trivial things like 1+1=2 ... Concerning formal methods to check whether a piece of code and even hardware is correct you could check the last milestones of at least one of the Open Source Industry-Level Automated Theorem Provers achievements: http://vstte.inf.ethz.ch/pdfs/vstte-moore-position.pdf https://www.cs.utexas.edu/users/moore/publications/talks/machines-2015.pdf

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Oberon program compilation, linking and execution on Windows or Linux.
by Srinivas Nayak 29 Jan '16

29 Jan '16

Dear All, Normally a C program when compiled, produces object file. Object file contains machine level code and symbol table. Object files (along with library object files) are linked using a linker to generate an executable file. Finally loader takes care of loading the shared libraries and executing the program. How these things happen for Oberon language programs on Windows or Linux? Any document describes this in detail (mostly what happens after finishing typing a Oberon Program to program execution start)? With thanks and best regards, Yours sincerely, Srinivas Nayak Home: http://www.mathmeth.com/sn/ Blog: http://srinivas-nayak.blogspot.in/

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Input.Timer in Native Oberon
by peter＠easthope.ca 29 Jan '16

29 Jan '16

>From joerg.straube at iaeth.ch Tue Jan 12 11:31:53 2016 > I like to move around the caret with my keyboard instead of the mouse ... Input.Timer translates keypad arrow activation (KP-Right for example) to a displacement (INC(kdx, i) for example). For time interval counter0, the displacement increment is i := counter0 DIV (100 DIV 12)+1; Isn't 100 DIV 12 always 8? Why not this arithmetic? i := counter0 DIV 8+1; Thanks, ... Lyall E. -- 123456789 123456789 123456789 123456789 123456789 123456789 123456789 12 Tel +1 360 639 0202 http://easthope.ca/Peter.html Bcc: peter at easthope. ca

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Re (2): Input.Timer in Native Oberon
by peter＠easthope.ca 28 Jan '16

28 Jan '16

From: Paul Reed <paulreed(a)paddedcell.com>, Thu, 28 Jan 2016 19:16:01 +0000 > ... not if it's > > i := counter0 DIV 100 * 12 + 1; > > so the original "why" still stands, right? :) Suppose that in an earlier version, either "100" or "12" was a more complex expression. The expression was simplified but the further simplification was omitted? Another small oddity. Except for a special case, counter1 is incremented before it is initialized. If the compiler initializes it to 0 or if the initial value happens to be less than 10, no harm is done. Otherwise, counter1 will eventually overflow. It should be initialized as counter0 is, in the body of Input. Regards, ... Lyall E. -- 123456789 123456789 123456789 123456789 123456789 123456789 123456789 12 Tel +1 360 639 0202 http://easthope.ca/Peter.html Bcc: peter at easthope. ca

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Particularly Useful Oberon Implementations
by jwr＠robrts.net 28 Jan '16

28 Jan '16

As stated in my previous message, in December I purchased an OberonStation, and am currently trying to understand which implementations of Oberon (in addition to that of Project Oberon 2013) are also valuable to obtain and study. I am also interested in those valuable to USE: implementations which provide certain features or tools useful for programming, documentation, data conversion or transfer, networking, drivers for particular devices, etc. It currently appears to me that the following are particularly useful (for my purposes). I am interested in feedback concerning these and others you think valuable for particular reasons. I remain fairly puzzled regarding exactly which version numbers, release dates, and download locations are most appropriate for study and use of ETH Oberon / LEO / NO / LNO / ALO. Project Oberon 2013, Niklaus Wirth and Paul Reed http://www.projectoberon.com/ https://www.inf.ethz.ch/personal/wirth/ AStrobe for RISC5, Chris Burrows, http://www.astrobe.com/default.htm RISC5 emulator, Peter De Wachter, https://github.com/pdewacht/oberon-risc-emu OLR Oberon Linux Revival, Peter Matthias, http://oberon.wikidot.com/ Experimental Oberon, Andreas Pirklbauer, https://github.com/andreaspirklbauer NO Native Oberon, ETH, via http://www.oberon.ethz.ch/downloads/index (see note at OCP site to replace ftp.inf.ethz.ch/pub in all links with ftp.ethoberon.ethz.ch) also note Version 2.3.6 and 2.3.7 Alpha at http://sourceforge.net/projects/nativeoberon/files/nativeoberon/ LNO Linux Native Oberon, ETH, from www.oberon.ethz.ch/downloads/index LEO Linux ETH Oberon = ETH Oberon (2.4.3) for Linux x86, possibly at ftp://ftp.ethoberon.ethz.ch/ETHOberon/Unix/x86.Linux/ ALO ARM Linux Oberon (for Raspberry Pi), ETH & Peter Matthias, see https://lists.inf.ethz.ch/pipermail/oberon/2014/007404.html not clear where to download, perhaps replaced by OLR? OCP, Oberon Community Platform, http://www.ocp.inf.ethz.ch/wiki/OCP/Download Pow! [Windows Oberon-2], JKU Linz, http://www.fim.uni-linz.ac.at/pow/ BlackBox Component Builder, Oberon Microsystems, http://www.oberon.ch/blackbox.html Gardens Point Component Pascal, K John Gough, http://gpcp.codeplex.com/ Crazy-Fresh A2, Bernhard Treutwein, http://sourceforge.net/projects/a2oberon/files/ Are other versions of AOS/UnixAOS/Bluebottle/A2 particularly useful? Of note, http://oberon07.com/compilers.xhtml is a useful list of various Oberon compilers. -- John Roberts

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Re: [Oberon] Variadic functions or procedures, VARARG ...
by John R. Strohm 28 Jan '16

28 Jan '16

Actually, type checking is one of the important concepts of modern programming languages, PERIOD. The whole point of variadic procedures is to allow varying-length parameter lists, with varying parameter types. It was originally invented to allow printf() adn their ilk in C. Variadic procedures break type checking, by definition. (Yes, this does mean that C, and C++ because of the backwards-compatibility requirement observed by Stroustrup, are inherently broken, by design.) There are REASONS why the designers of Ada chose not to do that. (And there are reason why Bell Labs declined to submit a C-based candidate language to the DOD1 evaluation, that eventually yielded Ada.) --- joerg.straube(a)iaeth.ch wrote: From: Jörg Straube <joerg.straube(a)iaeth.ch> To: ETH Oberon and related systems <oberon(a)lists.inf.ethz.ch> Subject: Re: [Oberon] Variadic functions or procedures, VARARG ... Date: Wed, 27 Jan 2016 13:39:56 +0100 Lars One of the important concepts of Oberon is type checking be it during compile time or during runtime in case of inheritance. So the problem with variadic is rather the missing types of the arguments than the nbr of arguments. If all arguments have the same type (eg INTEGER) you can use open arrays in Oberon PROCEDURE Variadic (arglist: ARRAY OF INTEGER) Jörg > Am 27.01.2016 um 03:03 schrieb Douglas G. Danforth <danforth(a)greenwoodfarm.com>: > > Lars, > I would side step the issue and replace the needed compiler functionality > with a run time solution where the variable number of arguments is replaced with > a pointer to a list (of arguments). Very simple. > -Doug Danforth > > >> On 1/26/2016 5:33 PM, Lars wrote: >> Hi, I can't find any information on Variadic functions for oberon or how >> one would interface to a C function that is variadic. Does oberon use any >> trick to support this, or it forbids you from using variadic or >> interfacing with variadic? >> >> Just to recap what variadic means, it's a function like this: >> >> PROCEDURE Something(param1: INTEGER; otherparams...) >> >> The ... means multiple parameters. In freepascal I believe this is known >> as VARARGS whereas C and golang call it variadic function. >> >> I'm guessing this is forbidden because oberon prefers everything to be >> fixed and known up front, and variadic functions go against the psychic >> programmer philosophy of huge design up front and knowning everything >> about everything. i.e. define the exact amount of parameters up front, or >> go home and you aren't welcome here... or something like that. >> >> But how would oberon interact with a C library with variadic function >> accepting multiple parameters? >> >> Varidiac functions have been proven to be extremely useful in Golang >> although they are one of those double edged swords that is extremely >> useful, until someone uses it for abuse. So I am guessing oberon outright >> forbids it... >> >> Any information would be helpful. Would also be nice to hear Wirth's >> comments on it in one of his books or articles since he refuses to >> communicate with Human DNA and only communicates with Wine and Cheese >> eating non spinach alien DNA's. (this is a serious question about variadic >> function support in oberon, but the email most definitely contains some >> humor worth every nickle) >> -- >> Oberon(a)lists.inf.ethz.ch mailing list for ETH Oberon and related systems >> https://lists.inf.ethz.ch/mailman/listinfo/oberon > > -- > Oberon(a)lists.inf.ethz.ch mailing list for ETH Oberon and related systems > https://lists.inf.ethz.ch/mailman/listinfo/oberon -- Oberon(a)lists.inf.ethz.ch mailing list for ETH Oberon and related systems https://lists.inf.ethz.ch/mailman/listinfo/oberon

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