advent_13_2022.py

"""
SPOILER ALERT!

Problem at: https://adventofcode.com/2022/day/13


This one was made quite easy by using Python's native comparison heuristics
along with operator overloading. 

Part 2 was ready without a single new line of code on the class- just adding the markers,
and applying "sorted" and the ".index" method on the data

"""


class Day13List:
    def __init__(self, data):
        data = data.strip()
        if data.isdigit():
            self.value = int(data)
            self.data = None
        else:
            self.value = None
            self.parse(data)
    def parse(self, data):
        cls = type(self)
        if data[0] != "[":
            raise ValueError()
        start0 = 0
        counter = 1
        tokens = []
        inner_num = inner_list = ""
        for char in data[1:]:
            if char == "[":
                counter += 1
                inner_list += char
            elif char == "]":
                if inner_num:
                    tokens.append(cls(inner_num))
                    inner_num = ""
                counter -= 1
                if counter == 0:
                    break
                elif counter == 1:
                    tokens.append(cls(inner_list + "]"))
                    inner_list = ""
                else:
                    inner_list += char
            elif inner_list:
                inner_list += char
            elif char == ",":
                if inner_num:
                    tokens.append(cls(inner_num))
                    inner_num = "" 
                else:
                    #asublist had been added when its bracked closed
                    pass
            elif char.isdigit():
                inner_num += char
        self.data = tokens
    def wrap(self):
        if self.data is not None:
            return self
        cls = type(self)
        instance = cls.__new__(cls)
        instance.value = None
        instance.data = [self]
        return instance
    def _cmp(self, other, op):
        if self.value is not None and other.value is not None:
            return op(self.value, other.value)
        x = self.wrap()
        y = other.wrap()
        return op(x.data, y.data)
    
    def __eq__(self, other):
        return self._cmp(other, eq)
        
    def __lt__(self, other):
        return self._cmp(other, lt)
    def __repr__(self):
        if self.value is not None:
            return str(self.value)
        return "[" + ", ".join(repr(item) for item in self.data) + "]"