lots of cleanup

advent/days/day09/solution.py

@@ -1,19 +1,19 @@
 from __future__ import annotations
 from dataclasses import dataclass
 
-from typing import Iterator
+from typing import Iterator, Self
 
 day_num = 9
 
 
 def part1(lines: Iterator[str]) -> int:
-    lst = [Command.parse(line) for line in lines]
-    return Command.walk(lst, 2)
+    commands = (Command.parse(line) for line in lines)
+    return simulate(commands, 2)
 
 
 def part2(lines: Iterator[str]) -> int:
-    lst = [Command.parse(line) for line in lines]
-    return Command.walk(lst, 10)
+    commands = (Command.parse(line) for line in lines)
+    return simulate(commands, 10)
 
 
 @dataclass(frozen=True, slots=True)
@@ -21,18 +21,18 @@ class Point:
     x: int
     y: int
 
-    @staticmethod
-    def parse_direction(char: str) -> Point:
+    @classmethod
+    def parse_direction(cls, char: str) -> Self:
         """ Parses the given direction to a Point. May raise if invalid """
         match char:
             case 'R':
-                return Point(1, 0)
+                return cls(1, 0)
             case 'U':
-                return Point(0, 1)
+                return cls(0, 1)
             case 'L':
-                return Point(-1, 0)
+                return cls(-1, 0)
             case 'D':
-                return Point(0, -1)
+                return cls(0, -1)
             case _:
                 raise Exception(f"Unkown Direction: {char}")
 
@@ -65,8 +65,8 @@ class Command:
     dir: Point
     steps: int
 
-    @staticmethod
-    def parse(line: str) -> Command:
+    @classmethod
+    def parse(cls, line: str) -> Self:
         """ Parse a command line. My raise exception if the was an illegal line"""
         match line.split():
             case [dir, steps]:
@@ -74,20 +74,20 @@ class Command:
             case _:
                 raise Exception(f"Illegal line: {line}")
 
-    @staticmethod
-    def walk(lst: list[Command], rope_length: int):
-        """ Walks the whole rope in Planck length steps according to commands """
-        rope = [Point(0, 0)] * rope_length
-        visited = {rope[-1]}
-        for command in lst:
-            for _ in range(command.steps):
-                rope[0] = rope[0].add(command.dir)
-                for n in range(1, rope_length):
-                    moved_piece = rope[n].step_to(rope[n - 1])
-                    if not moved_piece:
-                        break
-                    rope[n] = moved_piece
-                    if n == rope_length - 1:
-                        visited.add(rope[n])
 
-        return len(visited)
+def simulate(lst: Iterator[Command], rope_length: int) -> int:
+    """ Walks the whole rope in Planck length steps according to commands """
+    rope = [Point(0, 0)] * rope_length
+    visited = {rope[-1]}
+    for command in lst:
+        for _ in range(command.steps):
+            rope[0] = rope[0].add(command.dir)
+            for n in range(1, rope_length):
+                moved_piece = rope[n].step_to(rope[n - 1])
+                if not moved_piece:
+                    break
+                rope[n] = moved_piece
+                if n == rope_length - 1:
+                    visited.add(rope[n])
+
+    return len(visited)