chui/assets/virtualMachine.js at master · Cyrus-0101/chui · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
const virtualMachine = (program) => {
    let programCounter = 0;

    let stack = [];

    let stackPointer = 0;

    while (programCounter < program.length) {
      let currentInstruction = program[programCounter];

      switch (currentInstruction) {
        case 'PUSH':
          stack[stackPointer] = program[programCounter + 1];
          stackPointer++;
          programCounter++;
          break;

        case 'ADD':
          right = stack[stackPointer - 1];
          stackPointer--;
          left = stack[stackPointer - 1];
          stackPointer--;
          stack[stackPointer] = left + right;
          stackPointer++;
          break;

        case 'MINUS':
          right = stack[stackPointer - 1];
          stackPointer--;
          left = stack[stackPointer - 1];
          stackPointer--;
          stack[stackPointer] = left - right;
          stackPointer++;
          break;
      }

      programCounter++;
    }

    console.log('stacktop: ', stack[stackPointer - 1]);
};

let program = ['PUSH', 3, 'PUSH', 4, 'ADD', 'PUSH', 5, 'MINUS'];

virtualMachine(program);