feat: command line interface options

app/Main.hs

@@ -1,39 +1,94 @@
+{-# LANGUAGE NamedFieldPuns #-}
+
 module Main where
 
-import qualified Ast.Types as T
+import qualified Ast.Parser as P
 import qualified Codegen.Codegen as C
+import qualified Control.Monad as M
+import qualified Control.Monad.Trans.Except as E
 import qualified Data.Text.Lazy as TL
-import qualified LLVM.Pretty as P
+import qualified LLVM.Pretty as LLVM
+import qualified Options.Applicative as O
+import qualified System.Exit as EX
+import qualified System.IO as S
+
+data CompileError
+  = ParseError String
+  | CodegenError String
+  deriving (Show)
+
+data Options = Options
+  { input :: Maybe FilePath,
+    out :: FilePath,
+    verbose :: Bool
+  }
+
+optionsParser :: O.Parser Options
+optionsParser =
+  Options
+    <$> O.optional
+      ( O.strOption
+          ( O.long "input"
+              <> O.short 'i'
+              <> O.metavar "FILENAME"
+              <> O.help "Input file to read from (defaults to STDIN)"
+          )
+      )
+    <*> O.strOption
+      ( O.long "out"
+          <> O.metavar "FILENAME"
+          <> O.help "Output file for the generated LLVM IR"
+          <> O.value "demo/generated.ll"
+      )
+    <*> O.switch
+      ( O.long "verbose"
+          <> O.short 'v'
+          <> O.help "Enable verbose logging"
+      )
+
+optionsInfo :: O.ParserInfo Options
+optionsInfo =
+  O.info
+    (O.helper <*> optionsParser)
+    ( O.fullDesc
+        <> O.progDesc "A compiler that generates LLVM IR from a scheme-like language"
+        <> O.header "Scheme-to-LLVM Compiler"
+    )
+
+compile :: String -> E.ExceptT CompileError IO String
+compile input = do
+  ast <- case P.parse input of
+    Left err -> E.throwE $ ParseError (show err)
+    Right res -> return res
+
+  case C.codegen ast of
+    Left err -> E.throwE $ CodegenError (show err)
+    Right lmod -> return $ TL.unpack $ LLVM.ppllvm lmod
+
+logMsg :: Bool -> String -> IO ()
+logMsg verbose msg = M.when verbose $ S.hPutStrLn S.stderr ("[LOG] " ++ msg)
+
+readInput :: Maybe FilePath -> IO String
+readInput Nothing = getContents
+readInput (Just filePath) = readFile filePath
+
+handleError :: String -> String -> Bool -> IO a
+handleError errType errMsg verbose = do
+  S.hPutStrLn S.stderr $ "Error: " ++ errMsg
+  logMsg verbose $ "Compilation failed during " ++ errType ++ "."
+  EX.exitWith $ EX.ExitFailure 84
 
 main :: IO ()
 main = do
-  let ast =
-        T.AST
-          [ T.Define "value" (T.Lit (T.LInt 21)),
-            T.Define
-              "$$generated"
-              ( T.If
-                  (T.Lit (T.LInt 1))
-                  ( T.Call
-                      ( T.Lambda
-                          ["x"]
-                          ( T.Seq
-                              [ T.Define "example" (T.Lit (T.LInt 2)),
-                                T.Op T.Mult (T.Var "x") (T.Var "example")
-                              ]
-                          )
-                      )
-                      (T.Seq [T.Var "value"])
-                  )
-                  ( T.Call
-                      ( T.Lambda ["y"] (T.Seq [T.Op T.Sub (T.Var "y") (T.Lit (T.LInt 1))])
-                      )
-                      (T.Seq [T.Lit (T.LInt 2)])
-                  )
-              )
-          ]
-
-  let output = case C.codegen ast of
-        Left err -> error (show err)
-        Right lmod -> TL.unpack $ P.ppllvm lmod
-  writeFile "demo/generated.ll" output
+  Options {input, out, verbose} <- O.execParser optionsInfo
+  source <- readInput input
+
+  logMsg verbose "Starting compilation..."
+  result <- E.runExceptT $ compile source
+
+  case result of
+    Left (ParseError err) -> handleError "parsing" err verbose
+    Left (CodegenError err) -> handleError "parsing" err verbose
+    Right llvm -> do
+      writeFile out llvm
+      logMsg verbose $ "Compilation successful! Output written to: " ++ out

glados.cabal

@@ -31,7 +31,6 @@ library
     base ^>=4.17.2.1,
     bytestring >=0.11.2 && <0.12,
     containers >=0.6.7 && <0.7,
-    llvm-hs-pretty >=0.9.0 && <0.10,
     llvm-hs-pure >=9.0.0 && <9.1,
     megaparsec >=9.7.0,
     mtl >=2.2.2 && <2.3,
@@ -46,7 +45,9 @@ executable glados
     base ^>=4.17.2.1,
     glados,
     llvm-hs-pretty >=0.9.0 && <0.10,
+    optparse-applicative >=0.18.1 && <0.19,
     text,
+    transformers >=0.5.6 && <0.6,
 
   hs-source-dirs: app
   default-language: Haskell2010