Check types

TODO

@@ -1,4 +1 @@
-# Type analysis
-
-- Iterate the tree and apply the expression function on procedure expressions.
-- Check statement types.
+# Register allocation

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