2022 02: don't use strIndex

cherryblossom000 · Dec 6, 2022 · 9e51689 · 9e51689
1 parent e92ceb7
commit 9e51689
Showing 1 changed file with 7 additions and 4 deletions.
diff --git a/2022/02/main.idr b/2022/02/main.idr
@@ -13,8 +13,10 @@ Outcome = Int
 Input : Type
 Input = List (Shape, Int)
 
-partial parse : String -> Input
-parse = map (\l => (ord (l `strIndex` 0) - 65, ord (l `strIndex` 2) - 88)) . lines . trim
+parse : String -> Maybe Input
+parse = traverse ((\l => Just (ord !(getAt 0 l) - 65, ord !(getAt 2 l) - 88)) . fastUnpack)
+      . lines
+      . trim
 
 shapeScore : Shape -> Int
 shapeScore = (+1)
@@ -28,10 +30,11 @@ part1 = sum . map (\(a, b) => shapeScore b + outcomeScore ((b - a + 1) `mod` 3))
 part2 : Input -> Int
 part2 = sum . map (\(a, b) => shapeScore ((a + b - 1) `mod` 3) + outcomeScore b)
 
-partial main : IO ()
+main : IO ()
 main = do
 	Right input <- readFile {io = IO} "input.txt"
 	| Left e => die (show e)
-	let xs = parse input
+	let Just xs = parse input
+	| Nothing => die "parse error"
 	printLn $ part1 xs
 	printLn $ part2 xs