Oberon

All hail the elven king... wait, wrong Oberon. Oberon is a programming language named after the moon of Uranus, discovered in 1787 by William Herschel. The language was developed in the late 1980s by Niklaus Wirth and Jürg Gutknecht. Oberon is a descendant of Pascal and Modula-2, and it was designed to be a simpler, more modern alternative to these languages. Wikipedia

Hello World

(* BEGIN_FRAGLET *)
MODULE Fraglet;
  IMPORT Out;
BEGIN
  Out.String("Hello World!");
  Out.Ln
END Fraglet.
(* END_FRAGLET *)

Coding Guide

Language Version

Oberon (oberonc: JVM-based compiler)

Execution Model

• Compiled language: source (.mod) is compiled to JVM bytecode, then executed
• Your fragment is the entire module: it replaces the whole module between the injection markers
• Use MODULE Fraglet with BEGIN … END Fraglet. so the container runner can invoke the compiled main class

Key Characteristics

• Wirth-family language: structured, minimal syntax
• Case-sensitive; semicolons separate statements
• Module-based: each compilation unit is a MODULE with optional IMPORT
• Procedures and variables at module level
• No nested procedure definitions; procedures are declared in the module body before BEGIN

Fragment Authoring

Write a complete Oberon module. The fraglet is the full module: MODULE name; optional IMPORT; optional declarations; BEGIN … END name. The container compiles hello-world.mod and runs the module’s main entry; the module name must be Fraglet to match the runner.

Available Libraries

• Out: Out.String(s), Out.Int(i, n), Out.Ln for output
• Standard Oberon modules provided by oberonc runtime

Common Patterns

• Print: Out.String("message"); Out.Ln
• Print integer: Out.Int(42, 0); Out.Ln
• Variables: VAR x: INTEGER; in declaration part, then x := 5; in body
• Procedures: declare in declaration part, define before BEGIN
• Loops: WHILE condition DO … END
• Conditionals: IF condition THEN … ELSE … END

Examples

MODULE Fraglet;
  IMPORT Out;
BEGIN
  Out.String("Hello, World!");
  Out.Ln
END Fraglet.

MODULE Fraglet;
  IMPORT Out;
  VAR a, b: INTEGER;
BEGIN
  a := 5;
  b := 10;
  Out.String("Sum: ");
  Out.Int(a + b, 0);
  Out.Ln
END Fraglet.

MODULE Fraglet;
  IMPORT Out;
  VAR sum, i: INTEGER;
BEGIN
  sum := 0;
  i := 1;
  WHILE i <= 5 DO
    sum := sum + i;
    i := i + 1
  END;
  Out.String("Sum 1..5: ");
  Out.Int(sum, 0);
  Out.Ln
END Fraglet.

MODULE Fraglet;
  IMPORT Out;
  PROCEDURE Double(x: INTEGER): INTEGER;
  BEGIN
    RETURN x * 2
  END Double;
BEGIN
  Out.String("5 * 2 = ");
  Out.Int(Double(5), 0);
  Out.Ln
END Fraglet.

Notes

• Module name must be Fraglet so the container can run the compiled program
• Procedure declarations go between the IMPORT section and BEGIN
• Semicolons between statements; no semicolon after END

Connections

Container Info