Advent of Code day 5

parser.py

def param_accessor(instruction, position):
    try:
        if instruction[-2 - position] == "1":
            return lambda pointer, opcodes: opcodes[pointer+position]
    except IndexError:
        pass
    return lambda pointer, opcodes: opcodes[opcodes[pointer+position]]


def op_sum(pointer, opcodes, first_param, second_param):
    opcodes[opcodes[pointer+3]] = first_param(pointer, opcodes) + second_param(pointer, opcodes)
    return pointer + 4


def op_mul(pointer, opcodes, first_param, second_param):
    opcodes[opcodes[pointer+3]] = first_param(pointer, opcodes) * second_param(pointer, opcodes)
    return pointer + 4


def op_input(pointer, opcodes, *_):
    print("input")
    opcodes[opcodes[pointer+1]] = int(input())
    return pointer + 2


def op_print(pointer, opcodes, first_param, _):
    print("result: {}".format(first_param(pointer, opcodes)))
    return pointer + 2


def op_jump_if_true(pointer, opcodes, first_param, second_param):
    if first_param(pointer, opcodes) != 0:
        return second_param(pointer, opcodes)
    return pointer + 3


def op_jump_if_false(pointer, opcodes, first_param, second_param):
    if first_param(pointer, opcodes) == 0:
        return second_param(pointer, opcodes)
    return pointer + 3


def op_less_than(pointer, opcodes, first_param, second_param):
    opcodes[opcodes[pointer+3]] = 1 if first_param(pointer, opcodes) < second_param(pointer, opcodes) else 0
    return pointer + 4


def op_equal(pointer, opcodes, first_param, second_param):
    opcodes[opcodes[pointer+3]] = 1 if first_param(pointer, opcodes) == second_param(pointer, opcodes) else 0
    return pointer + 4

def end(*_):
    return None

OPERATIONS = {
    "1": op_sum,
    "2": op_mul,
    "3": op_input,
    "4": op_print,
    "5": op_jump_if_true,
    "6": op_jump_if_false,
    "7": op_less_than,
    "8": op_equal,
    "9": end,
}


def evaluate(opcodes):
    pointer = 0
    while pointer is not None:
        instruction = str(opcodes[pointer])
        print("instruction: {}".format(instruction))
        first_param = param_accessor(instruction, 1)
        second_param = param_accessor(instruction, 2)
        pointer = OPERATIONS[instruction[-1]](pointer, opcodes, first_param, second_param)
    return opcodes

with open("input") as stream:
    opcodes = stream.readlines()[0].strip().split(',')
    opcodes = [int(opcode) for opcode in opcodes]
    evaluate(opcodes)