Simple Object-Oriented Language Interpreter

Overview

This project presents a Scheme interpreter that executes code written in a simplified object-oriented language, inspired by Java/C syntax. It was developed as a college project for CSDS 345.

Interpreter Usage

The interpreter accepts two parameters:

• file: The name of the file containing the code to be interpreted.
• classname: The name of the class whose main method will be executed.

Example Usage:

(interpret "MyProgram.j" "B")

Interpreter Process

1. Parsing: Parses the specified file using the Scheme parser.
2. Class Lookup: Retrieves the designated class from the interpreter's state.
3. Main Method Execution: Calls the main method of the specified class.
4. Return Value: Returns the value produced by the main method.

Language Features

Object-Oriented Constructs:

• Classes
• Inheritance
• Objects
• Static and non-static (instance) variables and methods
• this and super object references
• Constructor methods
• Nested dot operator usage

Data Types:

• Integers
• Booleans
• Objects

Operators:

• Mathematical and comparison (for integers)
• Logical (for booleans)
• Dot operator for object member access
• new operator for object creation

Parser Constructs

Language Construct	Equivalent Scheme Representation
class A { ... }	(class A () body)
class B extends A { ... }	(class B (extends A) body)
static var x = 5;	(static-var x 5)
var y = true;	(var y true)
static function main() { ... }	(static-function main () body)
function f() { ... }	(function f () body)
function g();	(abstract-function g ())
class A { A(x) { ... } }	(constructor (x) body)
new A()	(new A)
a.x	(dot a x)
new A().f(3, 5)	(funcall (dot (new A) f) 3 5)

Example Program

class A {
  var x = 6;
  var y = 7;

  function prod() {
    return this.x * this.y;
  }

  function set2(a, b) {
    x = a;
    y = b;
  }
}

class B extends A {
  function set1(a) {
    set2(a, a);
  }

  static function main () {
    var b = new B();
    b.set1(10);
    return b.prod();
  }
}