IntComputer class for Advent-of-Code 2019

intcomputer.py

import logging
from collections import defaultdict
from collections import deque


# logging.basicConfig(level=logging.INFO, format="    %(message)s")
log = logging.getLogger(__name__)

# "parameter modes"
POSITION = 0
IMMEDIATE = 1
RELATIVE = 2


class IntComputer:
    class Halt(Exception):
        pass

    def __init__(self, reg0, inputs=()):
        self.ip = 0
        if not isinstance(reg0, (list, tuple)):
            reg0 = [int(x) for x in reg0.split(",")]
        self.offset = 0
        self.reg = defaultdict(int, dict(enumerate(reg0)))
        self.input = deque(inputs)
        self.output = deque()
        self._iterations = 0
        self._last_instruction = None
        self.op_map = {
            1: self.op_add,
            2: self.op_mul,
            3: self.op_input,
            4: self.op_output,
            5: self.op_jump_t,
            6: self.op_jump_f,
            7: self.op_lt,
            8: self.op_eq,
            9: self.op_offset,
            99: self.op_halt,
        }

    def op_add(self, x, y, z):
        self.reg[z] = self.reg[x] + self.reg[y]

    def op_mul(self, x, y, z):
        self.reg[z] = self.reg[x] * self.reg[y]

    def op_input(self, x):
        self.reg[x] = self.input.pop()

    def op_output(self, x):
        self.output.appendleft(self.reg[x])

    def op_jump_t(self, x, y):
        if self.reg[x]:
            self.ip = self.reg[y] - 3

    def op_jump_f(self, x, y):
        if not self.reg[x]:
            self.ip = self.reg[y] - 3

    def op_lt(self, x, y, z):
        self.reg[z] = int(self.reg[x] < self.reg[y])

    def op_eq(self, x, y, z):
        self.reg[z] = int(self.reg[x] == self.reg[y])

    def op_offset(self, x):
        self.offset += self.reg[x]

    def op_halt(self):
        raise IntComputer.Halt

    def step(self):
        opcode = self.reg[self.ip]
        op = self.op_map[opcode % 100]
        nargs = op.__func__.__code__.co_argcount
        args = []
        for i in range(1, nargs):
            mode = (opcode // 100) // (10 ** (i - 1)) % 10
            if mode == IMMEDIATE:
                args.append(self.ip + i)
            elif mode == POSITION:
                args.append(self.reg[self.ip + i])
            elif mode == RELATIVE:
                args.append(self.reg[self.ip + i] + self.offset)
        e = "%d %-10s ip=%-5d opcode=%05d offset=%-5d args=%s"
        log.debug(e, self._iterations, op.__name__, self.ip, opcode, self.offset, args)
        self._last_instruction = op.__func__
        op(*args)
        self._iterations += 1
        self.ip += nargs

    def run(self, until=None):
        while True:
            try:
                self.step()
            except IntComputer.Halt:
                break
            if self._last_instruction is until:
                break