Add Map to app

app/Main.hs

@@ -4,16 +4,20 @@ module Main where
 
 import System.IO
 import System.Directory
-import Data.Text (Text, pack, unpack, isInfixOf, lines, unlines)
+import Data.Text (Text, pack, unpack, isInfixOf, lines, unlines, strip, splitOn)
 import qualified Data.Text.IO as TIO
 import Control.Monad (when)
 import Data.List (sortBy)
 import Data.Ord (comparing)
 import Data.Char (isAlpha)
+import qualified Data.Map as Map
+import Data.Function (on)
 
 todoFile :: FilePath
 todoFile = "todo.txt"
 
+type TaskMap = Map.Map Int Text
+
 main :: IO ()
 main = do
     putStrLn "Welcome to the Haskell Todo App"
@@ -39,8 +43,9 @@ displayTasks = do
     if exists
         then do
             contents <- TIO.readFile todoFile
+            let taskMap = parseTasks contents
             putStrLn "Tasks:"
-            TIO.putStrLn contents
+            mapM_ (putStrLn . showTask) (Map.toList taskMap)
         else putStrLn "No tasks found."
     main
 
@@ -49,23 +54,31 @@ addTask = do
     putStr "Enter the task: "
     hFlush stdout
     task <- getLine
-    TIO.appendFile todoFile (pack task <> "\n")
+    exists <- doesFileExist todoFile
+    if exists
+        then do
+            contents <- TIO.readFile todoFile
+            let taskMap = parseTasks contents
+                newId = if Map.null taskMap then 1 else fst (Map.findMax taskMap) + 1
+                newTaskMap = Map.insert newId (pack task) taskMap
+            TIO.writeFile todoFile (serializeTasks newTaskMap)
+        else TIO.writeFile todoFile (pack task <> "\n")
     putStrLn "Task added."
     main
 
 filterTasksByTag :: IO ()
 filterTasksByTag = do
-    putStr "Enter the tag to filter by (e.g., +chapelShelving): "
+    putStr "Enter the tag to filter by (e.g., +GarageSale): "
     hFlush stdout
     tag <- getLine
     exists <- doesFileExist todoFile
     if exists
         then do
             contents <- TIO.readFile todoFile
-            let tasks = Data.Text.lines contents
-                filteredTasks = filter (isInfixOf (pack tag)) tasks
+            let taskMap = parseTasks contents
+                filteredTasks = Map.filter (isInfixOf (pack tag)) taskMap
             putStrLn "Filtered tasks:"
-            TIO.putStrLn (Data.Text.unlines filteredTasks)
+            mapM_ (putStrLn . showTask) (Map.toList filteredTasks)
         else putStrLn "No tasks found."
     main
 
@@ -75,10 +88,10 @@ sortTasksByPriority = do
     if exists
         then do
             contents <- TIO.readFile todoFile
-            let tasks = Data.Text.lines contents
-                sortedTasks = sortBy comparePriority tasks
+            let taskMap = parseTasks contents
+                sortedTasks = sortBy (comparePriority `on` snd) (Map.toList taskMap)
             putStrLn "Sorted tasks by priority:"
-            TIO.putStrLn (Data.Text.unlines sortedTasks)
+            mapM_ (putStrLn . showTask) sortedTasks
         else putStrLn "No tasks found."
     main
 
@@ -86,6 +99,15 @@ comparePriority :: Text -> Text -> Ordering
 comparePriority t1 t2 = comparing getPriority t1 t2
 
 getPriority :: Text -> Maybe Char
-getPriority t = case unpack t of
+getPriority t = case unpack (strip t) of
     ('(':p:')':_) | isAlpha p -> Just p
-    _                         -> Nothing
+    _                         -> Nothing
+
+parseTasks :: Text -> TaskMap
+parseTasks = Map.fromList . zip [1..] . Data.Text.lines
+
+serializeTasks :: TaskMap -> Text
+serializeTasks = Data.Text.unlines . map snd . Map.toList
+
+showTask :: (Int, Text) -> String
+showTask (_, task) = unpack task

package.yaml

@@ -23,6 +23,7 @@ dependencies:
    - base >= 4.7 && < 5
    - text
    - directory
+   - containers
 
 ghc-options:
 - -Wall

todo-app.cabal

@@ -35,6 +35,7 @@ library
   ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
   build-depends:
       base >=4.7 && <5
+    , containers
     , directory
     , text
   default-language: Haskell2010
@@ -50,6 +51,7 @@ executable todo-app
   ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
+    , containers
     , directory
     , text
     , todo-app
@@ -67,6 +69,7 @@ test-suite todo-app-test
   ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
   build-depends:
       base >=4.7 && <5
+    , containers
     , directory
     , text
     , todo-app