Interpreter

by Ganesh Sankaran

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This is a simple interpreter for a simple stack-based ISA.

Execution

python3 interpreter.py <program name>

A sample program is given in program.txt.

ISA

The ISA is based on Whitespace's. My mnemonics can be found in handlers.py:

handlers = {
    'push': push,
    'pop': pop,
    'dup': dup,
    'swap': swap,
    'add': add,
    'sub': sub,
    'mul': mul,
    'div': div,
    'mod': mod,
    'load': load,
    'store': store,
    'label': label,
    'call': call,
    'jump': jump, # unconditional jump
    'jnil': jnil, # jump if TOS == 0
    'jneg': jneg, # jump if TOS < 0
    'ret': ret,
    'halt': halt,
    'getchar': getchar,
    'getint': getint,
    'putchar': putchar,
    'putint': putint
}

VM Stack and Heap

The object vm in handlers.py contains the program counter, return address stack, operand stack, and runtime heap.