[Oberon] Re (n): syntax in BB, CP, GPCP and V4 ...
Jan de Kruyf
jan.de.kruyf at gmail.com
Tue Jul 25 14:18:03 CEST 2017
Would you have the source code for the *.Mod files Dieter?
Jan.
On Tue, Jul 25, 2017 at 10:00 AM, Dieter <d.gloetzel at web.de> wrote:
> Just to remind you, that there exists a nice prettyprinter written by G.
> Feldmann, running on ETHOberon Windows plugin.
> Regards,
> Dieter
>
>
> Am 25.07.2017 um 01:44 schrieb Hans Klaver:
>
> Jörg wrote:
>
> Indentation is indeed a totally personal thing.
>
>
> It is interesting to catalogue the different indentation styles used by
> some well known (and less well known) programmers of Oberon and Component
> Pascal source code. With one of the exercises of the Reiser & Wirth book as
> material I wrote out various indentation styles.
>
> Crudely four styles of indentation can be discerned:
> - No indentation (Daniel)
> - Minimal indentation (Reiser / Mössenböck); the difference between the
> two is in the indentation of declarations (e.g. VAR) at the procedure level
> - Classical indentation (Wirth & Gutknecht); has the most consistent
> indentation of scope levels.
> - Knuth indentation (Knuth / Campbell); also quite consistent, but rather
> convoluted.
>
>
> MODULE M; (* After Exercise 6.4 (p. 85) from Reiser & Wirth, Programming
> in Oberon *)
> IMPORT Out;
> VAR i, j: INTEGER;
> PROCEDURE A*;
> VAR i: INTEGER;
> PROCEDURE B(VAR i, j: INTEGER);
> VAR k: INTEGER;
> BEGIN k := i; i := j; j := k END B;
> BEGIN i := 2; B(i, j)
> END A;
> PROCEDURE C*;
> BEGIN A; i := 2*j;
> Out.Int(i, 5); Out.Int(j, 5); Out.Ln
> END C;
> BEGIN
> END M.C
>
> (**************************************)
>
> MODULE M; (* Daniel, http://www.waltzballs.org/other/prog.html#track *)
> IMPORT Out;
> VAR i,j:INTEGER;
>
> PROCEDURE A*;
> VAR i:INTEGER;
>
> PROCEDURE B(VAR i,j:INTEGER);
> VAR k:INTEGER;
> BEGIN k:=i;i:=j;j:=kEND B;
>
> BEGIN i:=2;B(i,j)
> END A;
>
> PROCEDURE C*;
> BEGIN A;i:=2*j;
> Out.Int(i,5);Out.Int(j,5);Out.Ln
> END C;
>
> BEGIN
> END M.C
>
> (**************************************)
>
> MODULE M; (* M. Reiser, The Oberon System
> and M. Reiser & N. Wirth, Programming in Oberon *)
> IMPORT Out;
> VAR i, j: INTEGER;
>
> PROCEDURE A*;
> VAR i: INTEGER;
>
> PROCEDURE B(VAR i, j: INTEGER);
> VAR k: INTEGER;
> BEGIN
> k := i; i := j; j := k
> END B;
>
> BEGIN
> i := 2; B(i, j)
> END A;
>
> PROCEDURE C*;
> BEGIN
> A; i := 2*j;
> Out.Int(i, 5); Out.Int(j, 5); Out.Ln
> END C;
>
> BEGIN
> END M.C
>
> (*************************************)
>
> MODULE M; (* H. Mössenböck, Object Oriented Programming in Oberon-2 *)
> IMPORT Out;
> VAR i, j: INTEGER;
>
> PROCEDURE A*;
> VAR i: INTEGER;
>
> PROCEDURE B(VAR i, j: INTEGER);
> VAR k: INTEGER;
> BEGIN
> k := i; i := j; j := k
> END B;
>
> BEGIN
> i := 2; B(i, j)
> END A;
>
> PROCEDURE C*;
> BEGIN
> A; i := 2*j;
> Out.Int(i, 5); Out.Int(j, 5); Out.Ln
> END C;
>
> BEGIN
> END M.C
>
> (**************************************)
>
> MODULE M; (* Wirth & Gutknecht, Project Oberon *)
> IMPORT Out;
> VAR i, j: INTEGER;
>
> PROCEDURE A*;
> VAR i: INTEGER;
>
> PROCEDURE B(VAR i, j: INTEGER);
> VAR k: INTEGER;
> BEGIN
> k := i; i := j; j := k
> END B;
>
> BEGIN
> i := 2; B(i, j)
> END A;
>
> PROCEDURE C*;
> BEGIN
> A; i := 2*j;
> Out.Int(i, 5); Out.Int(j, 5); Out.Ln
> END C;
>
> BEGIN
> END M.C
>
> (**************************************)
>
> MODULE M; (* Knuth. E.g. see: http://brokestream.com/tex.pdf *)
> IMPORT Out;
> VAR i, j: INTEGER;
>
> PROCEDURE A*;
> VAR i: INTEGER;
>
> PROCEDURE B(VAR i, j: INTEGER);
> VAR k: INTEGER;
> BEGIN k := i; i := j; j := k
> END B;
>
> BEGIN i := 2; B(i, j)
> END A;
>
> PROCEDURE C*;
> BEGIN A; i := 2*j;
> Out.Int(i, 5); Out.Int(j, 5); Out.Ln
> END C;
>
> BEGIN
> END M.C
>
> (**************************************)
>
> MODULE M; (* R. Campbell, Subsystem Lib for BlackBox Component Framework,
> see the Component Pascal Collection, http://www.zinnamturm.eu/ *)
> IMPORT Out;
> VAR
> i, j : INTEGER;
>
> PROCEDURE A*;
> VAR
> i : INTEGER;
>
> PROCEDURE B(VAR i, j : INTEGER);
> VAR
> k : INTEGER;
> BEGIN
> k := i; i := j; j := k
> END B;
>
> BEGIN
> i := 2;
> B(i, j)
> END A;
>
> PROCEDURE C*;
> BEGIN
> A;
> i := 2*j;
> Out.Int(i, 5); Out.Int(j, 5); Out.Ln
> END C;
>
> BEGIN
> END M.C
>
>
> Anyone can choose his or her favourite indentation style.
>
> I personally don't like the two extremes (Daniel and Knuth / Campbell).
> Imho they don't follow Einstein's criterium "Make it as simple as ...":
> Daniel's is too simplistic and Knuth's / Campbell's are too convoluted.
>
> The classic Wirth / Gutknecht style is the only style that is completely
> consistent: every scope has its own indentation.
> BlackBox uses this style as standard. See: https://hansklav.home.
> xs4all.nl/ProgrammingConventionsBB.pdf
>
> Some might find the Reiser / Mössenböck styles more aesthetically pleasing
> because of their simplicity. Although these styles are not as consistent as
> the Wirth / Gutknecht style, in practice this doesn't matter much because
> there is only one module scope per compilation unit, and nested procedures
> are rarely used in Oberon programs.
>
> The latter styles are used in two excellent books: *The Oberon System* by
> Martin Reiser and *Object-Oriented Programming in Oberon-2* by Hanspeter
> Mössenböck. These books are the two best typeset Oberon books there are
> (imho). Unfortunately both have long been out of print. A scanned copy of *The
> Oberon System* can be found on the internet here: http://oberoncore.ru/
> library/reiser_the_oberon_system_user_guide_and_programmers_manual , and
> there's a pdf-version of *OOP in Oberon-2* here: http://ssw.jku.
> at/Research/Books/Oberon2.pdf . In this pdf the source code indentation
> is not rendered entirely accurately, so also have look at a scanned version
> of this book: https://books.google.nl/books?id=BseoCAAAQBAJ&
> printsec=frontcover&dq=object+oriented+programming+in+
> oberon-2&hl=nl&sa=X&redir_esc=y#v=onepage&q=object%
> 20oriented%20programming%20in%20oberon-2&f=false
>
> --
> Hans Klaver
>
>
>
>
>
>
>
> --Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systemshttps://lists.inf.ethz.ch/mailman/listinfo/oberon
>
>
>
> --
> ____________________________________
> Dr. Dieter Glötzel
> Im Rosengarten 27
> 64367 Mühltal
> Tel.: 06151 / 360 82 72
>
>
> --
> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
> https://lists.inf.ethz.ch/mailman/listinfo/oberon
>
>
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