From 5e7683af32ecb769e986554e12465cbe9acb4a05 Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Fri, 9 Aug 2024 20:16:41 +0200
Subject: [PATCH] Check types

---
 TODO                              |  5 +----
 lib/Language/Elna/TypeAnalysis.hs | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/TODO b/TODO
index 6a2f85b..46877d5 100644
--- a/TODO
+++ b/TODO
@@ -1,4 +1 @@
-# Type analysis
-
-- Iterate the tree and apply the expression function on procedure expressions.
-- Check statement types.
+# Register allocation
diff --git a/lib/Language/Elna/TypeAnalysis.hs b/lib/Language/Elna/TypeAnalysis.hs
index 2544947..040a022 100644
--- a/lib/Language/Elna/TypeAnalysis.hs
+++ b/lib/Language/Elna/TypeAnalysis.hs
@@ -5,7 +5,7 @@ module Language.Elna.TypeAnalysis
 
 import Control.Applicative (Alternative(..))
 import Control.Monad.Trans.Except (Except, runExcept, throwE)
-import Control.Monad.Trans.Reader (ReaderT, asks, runReaderT)
+import Control.Monad.Trans.Reader (ReaderT, asks, runReaderT, withReaderT, ask)
 import qualified Data.Vector as Vector
 import qualified Language.Elna.AST as AST
 import Language.Elna.Location (Identifier(..))
@@ -56,7 +56,21 @@ typeAnalysis globalTable = either Just (const Nothing)
     . program
 
 program :: AST.Program -> TypeAnalysis ()
-program (AST.Program _declarations) = pure ()
+program (AST.Program declarations) = traverse_ declaration declarations
+
+declaration :: AST.Declaration -> TypeAnalysis ()
+declaration (AST.ProcedureDefinition procedureName _ _ body) = do
+    globalTable <- TypeAnalysis ask
+    case SymbolTable.lookup procedureName globalTable of
+        Just (ProcedureInfo localTable _) -> TypeAnalysis
+            $ withReaderT (const localTable)
+            $ runTypeAnalysis
+            $ traverse_ (statement globalTable) body
+        Just anotherInfo -> TypeAnalysis $ lift $ throwE
+            $ UnexpectedProcedureInfoError anotherInfo
+        Nothing -> TypeAnalysis $ lift $ throwE
+            $ UndefinedSymbolError procedureName
+declaration _ = pure ()
 
 statement :: SymbolTable -> AST.Statement -> TypeAnalysis ()
 statement globalTable = \case