Small VM

A minimalistic stack based virtual machine written in Luau, for the sake of typings.

Explanation

Using the vm is quite simple, with the introduction of constants, stack pointer and program counter (instruction pointer) a simple program can be carried out.

For example:

Let's define our constants, 10 and 20

local constants = {
    value("NUMBER", 10),
    value("NUMBER", 20)
}

We should now construct our program which we want to run. We need to use the opcodes.

local program = {
    Opcode.CONST, 1,
    Opcode.CONST, 2,
    Opcode.ADD,
    Opcode.HALT
}

Now the 1 and 2 may look a bit confusing, that's because how arrays work in Luau, starting from 1. They symbolise the indexes of the constants we want to push onto the stack, hence the opcode CONST. We then push ADD onto the stack, which adds the two top most values of the stack. HALT then halts the program and returns the top most value of the stack.

local constants = {
    value("NUMBER", 10),
    value("NUMBER", 20),
}

local program = {
    Opcode.CONST, 1,
    Opcode.CONST, 2,
    Opcode.ADD,
    Opcode.HALT
}

local result = run(program, constants)

print(result.value)

And now if you guessed correctly, the output will be 30 !!