code: WebAssembly + OOP

Mastering Object-Oriented Programming in WebAssembly: From High-Level to Low-Level · Mirko Sertic

This article explores how object-oriented programming concepts are implemented in WebAssembly, a low-level binary instruction format for stack-based virtual machines. It demonstrates the translation of high-level language features like classes, methods, and inheritance into WebAssembly's basic primitive types and functions. Through practical examples, it explains crucial concepts such as virtual function tables, memory management, and object allocation, providing insights into how modern compilers bridge the gap between high-level programming languages and WebAssembly's efficient but limited instruction set.

public class HelloWorld {

    public static int compute() {
        int a = 10;
        int b = 20;
        return a + b;
    }

    public static void main(String[] args) {
        int result = compute();
    }
}

How, lets take a look at the compile result in its WebAssembly textual representation with added comments by myself:

   ;;
   ;; Here we are doing some computation by adding two integers and returning them.
   ;;
   (func $HelloWorld_INTcompute (param $UNUSED i32) (result i32) (1)
         (local $var0 i32)  (2)
         (local $var1 i32)
         (set_local $var0
             (i32.const 10)
         )
         (set_local $var1
             (i32.const 20)
         )
         (return
             (i32.add     (3)
                 (get_local $var0)
                 (get_local $var1)
             )

         )
   )

   ;;
   ;; This is the original main method, which basically just calls the static compute method
   ;;
   (func $HelloWorld_VOIDmainA1TString (param $UNUSED i32) (param $p1 i32) (4)
         (local $var0 i32)
         (set_local $var0
             (call $HelloWorld_INTcompute (i32.const 0))
         )
         (return)
   )