ex_factorial.py

#!/usr/bin/env python
import argparse
import sys
import socket
import random
import struct
from sendutils import *
from headers import *

def test_fact(n):
    return ([
        RESET(),
        PUSH(n), # current number
        PUSH(1), # result
        NOP(),
        PUSH(1), # if n <= 1 then jump to end
        LOAD(0),
        LTE(),
        CJUMP(17),
        LOAD(0), # multiply current number with result and store it
        LOAD(1),
        MUL(),
        STORE(1),
        PUSH(1), # subtract 1 from current number
        LOAD(0),
        SUB(),
        STORE(0),
        JUMP(3), # jump to first NOP
        NOP(),
        SETRESULT(),
        METADATA(0),
        SETEGRESS(),
    ], [])

def main():
    if len(sys.argv) < 2:
        print "calculates factorial of <n> and returns result to sender"
        print "arguments: <n>"
        return

    n = int(sys.argv[1])
    instrs, stk = test_fact(n)
    send_probe(instrs, stk)

if __name__ == '__main__':
    main()