day 7: rewrite

use Data.Text

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

day7.hs

@@ -1,12 +1,21 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+import Data.Either (rights)
+import Data.Text (Text)
+import qualified Data.Text as T (head, lines, words)
+import qualified Data.Text.Read as T (decimal)
 import Data.Tree
+import Lib (readFile')
 
 -- this solution assumes that empty directories can exist,
 -- if you want to ignore that, there is a slightly different code in day7'.hs
--- needs cleaning and improvement
+
+-- needs cleaning and improvement, although i like the fact
+-- that the entire FS can be printed as a tree
 
 main :: IO ()
 main = do
-  tree <- snd . flip parse (emptyFs "/") . map words . lines <$> readFile "day7.in"
+  tree <- snd . flip parse (emptyFs "/") . map T.words . T.lines <$> readFile' "day7.in"
   putStr "Q1: "
   print $
     foldTree
@@ -26,18 +35,18 @@ main = do
       )
       tree
 
-type Filesystem = Tree (String, Int)
+type Filesystem = Tree (Text, Int)
 
 tail' :: [a] -> [a]
 tail' = drop 1
 
 -- wrapper to create an empty tree
-emptyFs :: String -> Filesystem
+emptyFs :: Text -> Filesystem
 emptyFs n = Node (n, 0) []
 
 -- This function is to replace a filesystem by name
 -- Used to replace empty directories with parsed directories in code
-replaceFs :: Filesystem -> String -> Filesystem -> Filesystem
+replaceFs :: Filesystem -> Text -> Filesystem -> Filesystem
 replaceFs (Node n xs) name fs =
   let (h, t) = span ((/= name) . fst . rootLabel) xs
    in Node
@@ -50,11 +59,17 @@ totalSize :: [Filesystem] -> Int
 totalSize = sum . map (snd . rootLabel)
 
 -- All directories/files are parsed here into leaves
-ls :: [[String]] -> [Filesystem]
-ls = map (\[a, b] -> if a == "dir" then Node (b, 0) [] else Node (b, read a) [])
+ls :: [[Text]] -> [Filesystem]
+ls =
+  map
+    ( \[a, b] ->
+        if a == "dir"
+          then Node (b, 0) []
+          else Node (b, fst . head $ rights [T.decimal a]) []
+    )
 
 -- main function where stuff happens
-parse :: [[String]] -> Filesystem -> ([[String]], Filesystem)
+parse :: [[Text]] -> Filesystem -> ([[Text]], Filesystem)
 parse input fs
   | null input || cur == ["$", "cd", ".."] = (tail' input, fs)
   | cur == ["$", "ls"] =