Fix linting.

src/holt59/aoc/2023/day23.py

@@ -2,24 +2,34 @@ import logging
 import os
 import sys
 from collections import defaultdict
+from typing import Literal, Sequence, TypeAlias, cast
 
 VERBOSE = os.getenv("AOC_VERBOSE") == "True"
 logging.basicConfig(level=logging.INFO if VERBOSE else logging.WARNING)
 
-Direction = {
+DirectionType: TypeAlias = Literal[">", "<", "^", "v", ".", "#"]
+
+Direction: dict[DirectionType, tuple[int, int]] = {
     ">": (0, +1),
     "<": (0, -1),
     "^": (-1, 0),
     "v": (+1, 0),
 }
 
-Neighbors = {".": ((+1, 0), (-1, 0), (0, +1), (0, -1)), "#": ()} | {
-    k: (v,) for k, v in Direction.items()
-}
+Neighbors = cast(
+    "dict[DirectionType, tuple[tuple[int, int], ...]]",
+    {
+        ".": ((+1, 0), (-1, 0), (0, +1), (0, -1)),
+        "#": (),
+    }
+    | {k: (v,) for k, v in Direction.items()},
+)
 
 
 def neighbors(
-    grid: list[str], node: tuple[int, int], ignore: set[tuple[int, int]] = set()
+    grid: list[Sequence[DirectionType]],
+    node: tuple[int, int],
+    ignore: set[tuple[int, int]] = set(),
 ):
     """
     Compute neighbors of the given node, ignoring the given set of nodes and considering
@@ -51,7 +61,7 @@ def neighbors(
 
 
 def reachable(
-    grid: list[str], start: tuple[int, int], target: tuple[int, int]
+    grid: list[Sequence[DirectionType]], start: tuple[int, int], target: tuple[int, int]
 ) -> tuple[tuple[int, int], int]:
     """
     Compute the next 'reachable' node in the grid, starting at the given node.
@@ -75,7 +85,7 @@ def reachable(
 
 
 def compute_direct_links(
-    grid: list[str], start: tuple[int, int], target: tuple[int, int]
+    grid: list[Sequence[DirectionType]], start: tuple[int, int], target: tuple[int, int]
 ) -> dict[tuple[int, int], list[tuple[tuple[int, int], int]]]:
     if start == target:
         return {}
@@ -85,7 +95,7 @@ def compute_direct_links(
         i, j = neighbor
         di, dj = Direction[grid[i][j]]
 
-        reach, distance = reachable(lines, (i + di, j + dj), target)
+        reach, distance = reachable(grid, (i + di, j + dj), target)
         direct[start].append((reach, distance + 2))
 
         direct.update(compute_direct_links(grid, reach, target))
@@ -124,7 +134,7 @@ def longest_path_length(
     return max_distance
 
 
-lines = sys.stdin.read().splitlines()
+lines = cast(list[Sequence[DirectionType]], sys.stdin.read().splitlines())
 n_rows, n_cols = len(lines), len(lines[0])
 start = (0, 1)
 target = (len(lines) - 1, len(lines[0]) - 2)