Oberon

Oral Exam English

index

The creatorThe historyThe useThe syntaxAn exampleConclusion

The creator - Niklaus Wirth

Swiss computer scientistborn February 1934Academic history

Electronics Engineering (ETH in Zürich)Master degree from Laval University ,

CanadaPh.D from University of California Berkeley

The creator - Niklaus Wirth

Assistant professor Comp Science at Stanford University and University of Zürich

Prof Informatics at ETH ZürichChief designer of Algol W, Pascal,

Modula, Modula-2, and Oberon

history

ALGOL – 60’sPascal – 70’s (first OO)Modula / Modula-2 –- 80’s (Modules)Oberon / Oberon-2 –- 80’s-90’s (OO)

The use

Pascal’s syntax, styleMore powerVery clear structureObject-Oriented20 years experienceExecutable problemUsed for teaching

The syntax - introduction

Case sensitive Line end ; Comment (* *)

MODULE Hello;(* first program *)IMPORT Out;

PROCEDURE Do*BEGIN

Out.String(“Hello”);Out.Ln;

END Do;

END Hello;

The syntax – Programme Structure

MODULE Hello;(* first program *)IMPORT Out;

PROCEDURE Do*BEGIN

Out.String(“Hello”);Out.Ln;

END Do;

END Hello;

MODULE PROCEDURE

BEGIN END

predefined words

The syntax – VAR & CONST

Predefined section Marked by “VAR” Varname : TYPE; Assignment operator

:= constants in

“CONST” section

PROCEDURE Vartest*CONST

numb = 6;VAR

a : INTEGER;b : REAL;c : REAL;

BEGINa := 3;c := numb*a;Out.Real(c);Out.Ln;

END Vartest;

The syntax - Datatypes

BOOLEAN TRUE / FALSECHAR ASCIISHORTINT -128...127INTEGER -32768...32767LONGINT -2E+9...2E+9REAL -3,4E+38...3.4E+38

The syntax – Loops / Conditions

WHILEWHILE (var1 < 3) DO

var2 := var2 + 1;

END;

REPEATREPEAT

var2 := var2 + 1;

UNTIL (var1 < 3);

LOOPLOOP

var2 := var2 + 1;

EXIT;

END;

IFIF (var1 = 3) THEN

Out.String(“Hurray”);

ELSE

Out.String(“Booh”);

END;

CASECASE var1 OF

1 : Out.String(“1”);

| 2 : Out.String(“2”);

| 3 : Out.String(“3”);

ELSE

Out.String(“none”);

END;

Example – GFX engine

Very powerful languageExample : my GFX engine

5 months experience in OberonNo other programming background

Many GFX possibilities

Example – GFX engine

Dynamic 3D Object Rendered by Oberon Backface culling Z-buffer Shading

Example – GFX examples

Conclusion

Structured, Compact, PowerfulMany possible compilersDownside : Executable filesUsed for teaching

Thank you for your attention

Any questions?