February 2007 - Oberon - mailman3.inf.ethz.ch

[BlackBox] Change in HostFiles
by Aubrey.McIntosh＠Alumni.UTexas.Net 18 Feb '07

18 Feb '07

I just sent this to the Blackbox mailing list. ---------- Forwarded message ---------- From: Aubrey.McIntosh(a)alumni.utexas.net <Aubrey.McIntosh(a)alumni.utexas.net> Date: Feb 17, 2007 7:37 PM Subject: Change in HostFiles To: blackbox(a)oberon.ch I wrote a small application to traverst all the directories on my windows machine and list the files. This program would not list directories that started with a dot "." I traced this behavior to HostFiles. I made a change in procedure LocList. You may search for the IF statement, and the third occurance should be in the correct procedure. I propose that this be considered a bug and a corresponding bugfix. IF find # invalid THEN REPEAT (* alm Feb 3, 2007 allow subdirectories beginning with "." *) IF (KERNEL32.FileAttrDirectory IN fd.attributes) & ~((fd.name$=".") OR (fd.name$="..")) & (LEN(fd.name$) < LEN(info.name)) THEN -- -- Aubrey McIntosh, Ph.D. -- -- Aubrey McIntosh, Ph.D.

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Re: N-O Scanner structure confusing ?
by Chris Glur 18 Feb '07

18 Feb '07

On 10 Feb 2007, Chris Glur <easlab(a)absamail.co.za> wrote: > > [...] > > Q- is it true that the Scanner is a descendant of the Reader ? > > > > Q- and that the Scanner 'uses' its parent to step&read as part > > of its scanning task ? > > > > Q - and that if the reader's char-position was publicly > > available, this would relate to the scanner's token position, > > since the scanner uses the reader ? > > > > Q - but the reader explicitly makes the read-postn-variable > > unavailable; isolating it via a function [procedure] ? > > [...] -- Thomas wrote: > All "Q"s need a "yes" except the last one, > cause the "scanner-reader" position is returned by Texts.Pos: > > Texts.Scanner record is an extension of a Texts.Reader record. > A Texts.Scanner record variable therefore has the two fields org and off. > The two fields describe the position of the scanner and are changed by a read. > Every scan normally makes at least one read. > After a scan, Texts.Pos(S) returns S.org+S.off, the sum of the two field values > changed by the read operation that forced that scan to terminate. > > That's what Oberon code may tell, > I wonder how execution of your code may telling you something else. ==== While I try to make a utility which will help expose the block structure and nested statements, I'm trying to investigate some meta-queries which have bothered me for a long time. One such query: 'why do they keep repeating eg. Hex2Ascii procs for several module', got the explanation that students need exercise. My present query is: why don't they write in a higher-level style eg. IF CaretPostn = NIL THEN Error('Caret not set'); Scan1stTkn(S); // which also inits Scanner; WHILE condition DO GetToken(S); DoStuff END; instead of eg. C.id := Oberon.get; C.F := NIL; C.car := NIL; C.text := NIL; Display.Broadcast(C); (* get caret position *) IF C.text = NIL THEN FAIL; ELSE Texts.OpenScanner(S, C.text, C.pos); Texts.Scan(S); WHILE condition DO Texts.Scan(S); DoStuff END I want to investigate a formal procedure/method of managing the high coupling of routines like Texts.Scan(S). Instead of just spreading all the part on the table, to be used as required. Ie. try some information hiding ? But I don't think my method of using the Scanner's inherited function value Texts.Pos(S) is 'sound'; beause Watson doesn't show Texts.Pos(S) for the Scanner, and you are not supposed to know that the scanner uses the reader and that therefore the Reader's Pos relates to the Scanner's Pos. Ie. it relies on undocumented, and hence potentially changeble conditions. Before I spend time to derive a 'pattern' for a cookbook method of knowing what arguments can be hidden, when executing a sequence of strongly coupled procs, perhaps some one else could comment. Eg. you are going to execute procs. P,Q,R in that sequence. And P has var-pars: a,b,c,d,e. And Q has var-pars: f,b,g,h. And R has var-pars: i,j,f,b. What N-O code seems to do is the most intuitive and natural, and perhaps unconsidered: expose all vars: a....j; creating code-clutter. And then just take what's needed when calling the next proc. So to use the TextScanner, the coder can't just look in a library description or use Watson. S/he must be concerned with too much of the internal workings of TextScanner - IMO. I recently spent some time on a spreadsheet, after a year[s] break, and was reminded that 'constrained coding'; ie. fill in the fields is much better that 'arty free flight'. Our creativety should be freed up for proper problems. Not for routine tasks which should be formally constrained, or even better, automated. Thanks, == Chris Glur.

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Bluebottle and Intel Mac without VM
by Alexander Hofmann 15 Feb '07

15 Feb '07

Hi, Does the Bluebottle ISO image currently available for download support USB-Keyboards within the Bootloader? I'm currently trying to boot Bluebottle on my Intel Mac Book without emulation, but beside the Message "OBERON loading..." nothing serious happens, till the Screen turns black and the System hangs... I would like to change some of the config-strings, but can't get into the Editor, holding down [shift] doesn't work... (I remember some previous version of Bluebottle succeeded in displaying the config-strings) Does anyone else have an Intel Mac and is trying to boot (or even succeeded in booting) Bluebottle? best regards, Alexander Hofmann. PS: I've already sent this message some days ago, but didnt' get it back from the list, thats why I'm sending it again... if you already got it, please excuse me...

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Re: [Oberon] Fragen was 'Status quo'
by Andreas Känner 15 Feb '07

15 Feb '07

Hi Ulrich and the others, for me the most appealing thing is, that the Oberon System is a complete development environment and runtime system with GUI support. The language is strongly typed and has a flexible inheritance mechanism. In comparison to many other and newer languages Oberon has a simple syntax which is easy to understand. Not to forget the garbage collector. I don't want to use Oberon commercially. Only for my own interest. I want to test/prototype some graphic algorithms with ist and I need a GUI to verify the results. A complete Oberon System with GUI would be nice. Reading the suggestions by the other members on this mailing list I see this candidates : POW ETH Oberon Sytem for Windows, Linux or native Blackbox Bluebottle Due to the fact that my main development platform is Mac OS X, nothing on this list fits really well. I would wish that the Oberon System had been ported to various platforms using libSDL or a similar cross platform library. But I'm willing to experiment in order work with Oberon. I have a PC too but I don't want to use Windows. Therfore I end up with this candidates: Bluebottle ETH Oberon System for Linux or native I have not found a recently build ETH Oberon System for any platform, but Bluebottle is updated frequently. Is there any progress with ETH Oberon or is all activity going into Bluebottle? Thank you for all the answers, Andreas Känner ulrich ulrich schrieb: > hallo Andreas, > > was gefällt Dir an Oberon und was willst Du damit machen? > > freundliche Grüße, > > Ulrich > > > > ____________________________________________________________________________________ > Food fight? Enjoy some healthy debate > in the Yahoo! Answers Food & Drink Q&A. > http://answers.yahoo.com/dir/?link=list&sid=396545367 >

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WinAos 3.02
by Felix Friedrich 15 Feb '07

15 Feb '07

A new release of WinAos (version 3.02) is available for download on http://www.bluebottle.ethz.ch/WinAos/ Felix bugfixes - Win32.AosTCP.Mod: some connections never got closed, is now done via close timer - Minor Bugfix in Win32.WinMenus.Mod modified/new features - A right mouse click on boundary of textframes works as selection only if SHIFT key is pressed at the same time. - Ctrl+Backspace now serves as substitution for the break key - SHIFT+F1 now serves as substitution for the menu-key (for zooming etc.) in Windows (which itself is a substitution for the windows-key that cannot be used in WinAos). - The system configuration is not written to the Oberon.Text any more each time when the system is closed - Very long (>64) filenames are now also supported in Oberon. Texts.Scanners and Attributes.Scanners do also accept long strings now Many Gadgets adapted to long strings. - The compiler now supports a display of warning messages for never used variables, types and procedures.

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Status quo?
by Andreas Känner 15 Feb '07

15 Feb '07

Hi, I'm a Objective-C / Cocoa developer by trade. In my spare time I look into other programming languages as well. Now I found Oberon and I think it is amazing. I have some questions, which I hope will be answered by someone on this list: - is there something like an active developer community? - is Oberon mainly an academic or a commercial endeavour or is it driven by an Open Source community? - if someone wants to start programming in Oberon which environment do you suggest? (In respect to support from the community) Thank you, Andreas Känner

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An Overview of Parallelism
by Douglas G. Danforth 11 Feb '07

11 Feb '07

Mortimer.CA writes with a recently released report from Berkeley entitled "The Landscape of Parallel Computing Research: A View from Berkeley:" (http://www.eecs.berkeley.edu/Pubs/TechRpts/2006/EECS-2006-183.html) Generally they conclude that the 'evolutionary approach to parallel hardware and software may work from 2- or 8-processor systems, but is likely to face diminishing returns as 16 and 32 processor systems are realized, just as returns fell with greater instruction-level parallelism.' This assumes things stay 'evolutionary' and that programming stays more or less how it has done in previous years (though languages like Erlang (http://www.erlang.org/) can probably help to change this)."

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Re: N-O Scanner structure confusing ?
by Chris Glur 10 Feb '07

10 Feb '07

Thomas wrote: > [...] > > > > > Here's a simple job which I can't acheive -- directly yet. > > > 1. set the caret > > > 2. scan from the caret until the token "END" > > > 3. reset the caret after the found token. > > > > [...] > > > > Texts.Scan(S); > > IF (S.class = Texts.Name) & (S.s = "END") THEN > > TextFrames.SetCaret(F, Texts.Pos(S)); > > > > Some longer fraction of Version4 code, leaving out full > > preconditioning related to the frame: > > > > PROCEDURE Do*; (* Test.Do *) > > VAR F: TextFrames.Frame; S: Texts.Scanner; > > BEGIN > > F := Oberon.FocusViewer.dsc.next(TextFrames.Frame); > > IF F.hasCar THEN > > Texts.OpenScanner(S, F.text, F.carloc.pos); Texts.Scan(S); > > WHILE ~S.eot & ((S.class # Texts.Name) OR (S.s # "END")) DO > > Texts.Scan(S) > > END;(***) > > IF ~S.eot THEN > > TextFrames.SetCaret(F, Texts.Pos(S)) > > END > > END > > END Do; > > > > In a frame viewing all lines of this procedure at once > > place the caret within these lines in front of the first "END" > > which is of class Texts.Name (before "(***)"), invoke the > > "Test.Do" command, the caret should show up > > just to the right of the semicolon that follows this "END". > > Invoke the command again and the caret jumps to a position > > behind the next END. > > Bob Walkden wrote:- > I use the ETH version for Windows, and the native version on bare > Intel hardware. N-O does not seem to have Oberon.FocusViewer. > Anybody know where the FocusViewer variable is in N-O? > If I had ETH version for Windows and time perhaps I'd examine what "Oberon.FocusViewer" does; and then see if N-O needs/has the same requirement. Re. TextsScanner being designed for command parameter read, and not used for the compiler, it's difficult to prove a 'non-existence' ? The compiler seems to have over 20 modules. The algorithm to search if/where the compiler uses the TextsScanner to get the tokens is interesting: 1. Watson.ShowDef Compiler.Compile == shows <list of imports> 2. Search in <list of imports>.Mod for "Texts.Scan" 3. and list the containing PROC names 4. manually examine the <list of PROC names> for a likely 'get next token' task. 5. manually analyse the containing code. And back to the original question, let's use a more theoretical approach: Q- is it true that the Scanner is a descendant of the Reader ? Q- and that the Scanner 'uses' its parent to step&read as part of its scanning task ? Q - and that if the reader's char-position was publicly available, this would relate to the scanner's token position, since the scanner uses the reader ? Q - but the reader explicitly makes the read-postn-variable unavailable; isolating it via a function [procedure] ? Thanks for any feedback, == Chris Glur. PS. for the first time 'TextMail.Directory' locked, for me. Luckily, with the recent Transmit authenticate requirement by my ISP I had investigated using Telnet to 'manually step' the pop-server. BTW when I occasionally look at the Transmit-authenticate field of mails which I've received, I never see ANY that are authenticated ? Except for ones which I've sent. I'm guessing that the ISP is putting a special requirement on me because I don't use M$-outsp00k !! It was a big problem to 'unlock TextMail.Directory' : I've got 2 'names' and the one directory had no problem. Also from watching the modem lights, I could see that some of the first few dir-entries were down-loading, before it locked. Under N-O I could use <Ctrl/Break> to escape the lock. A finer point is that the 'down-loaded but not yet displayed' dir-entries I think can be seen at the head of the next download; but which I didn't confirm. Under linux-ETH-Oberon, I could not recover. I need to setup an interupt, mentioned in the documentation Currently I've got about 40 mails which I leave on the server, and via telnet I could see that some mail after No.50 was causing the SERVER TO HANG. Ie. also with telnet the server was hanging. So it seems not to be a N-O problem. I suspect it was one of our ETH-posts re. "sound & video recording and reverse playback...etc.", because one of the fields was very long and full of non-ascii chars. Perhaps this bad format only arrived at *MY* ISP. But I'm interested to know if others also had a bad header. The reason why I couldn't investigate deeper was: 1. with a dozen spam a day, the job can't be left, while spam could overflow my box, due to inability to delete. 2. the manual-telnet operation is complex, since after deleting, the higher numbered mail 'fall down to fill the hole', but only after logging off. 3. On line costs.

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backwards playing video with WMPlayer, MPEG, DivX ?
by Patrick.Hunziker＠unibas.ch 10 Feb '07

10 Feb '07

Is there a simple way to play parts of a mpeg and divx video in bluebottle backwards ? Thanks Patrick ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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MediaPlayer VOB
by Patrick.Hunziker＠unibas.ch 09 Feb '07

09 Feb '07

Does WMPlayer play VOB video files (which are a kind of mpeg-2 files) ? Greetings Patrick ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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