Create numerated temporary variables

elna.cabal

@@ -32,6 +32,7 @@ library elna-internal
     import: warnings
     exposed-modules:
         Language.Elna.AST
+        Language.Elna.CodeGenerator
         Language.Elna.Intermediate
         Language.Elna.Location
         Language.Elna.NameAnalysis

lib/Language/Elna/CodeGenerator.hs

@@ -0,0 +1,3 @@
+module Language.Elna.CodeGenerator
+    (
+    ) where

lib/Language/Elna/Intermediate.hs

@@ -21,6 +21,7 @@ import Language.Elna.SymbolTable (SymbolTable, Info(..))
 import qualified Language.Elna.SymbolTable as SymbolTable
 import Data.Foldable (Foldable(..), foldrM)
 import GHC.Records (HasField(..))
+import qualified Data.Text as Text
 import qualified Data.Text.Lazy.Builder.Int as Text.Builder
 import qualified Data.Text.Lazy.Builder as Text.Builder
 import qualified Data.Text.Lazy as Text.Lazy
@@ -31,25 +32,37 @@ data Operand
     deriving (Eq, Show)
 
 newtype Label = Label Text
-    deriving (Eq, Show)
+    deriving Eq
 
-data Variable = Variable Text | TempVariable
-    deriving (Eq, Show)
+instance Show Label
+  where
+    show (Label label) = '.' : Text.unpack label
 
-newtype Generator = Generator
+data Variable = Variable Text | TempVariable Int32
+    deriving Eq
+
+instance Show Variable
+  where
+    show (Variable variable) = '$' : Text.unpack variable
+    show (TempVariable variable) = '$' : show variable
+
+data Generator = Generator
     { labelCounter :: Int32
+    , temporaryCounter :: Int32
     } deriving (Eq, Show)
 
 instance Semigroup Generator
   where
     lhs <> rhs = Generator
         { labelCounter = getField @"labelCounter" lhs + getField @"labelCounter" rhs
+        , temporaryCounter = getField @"temporaryCounter" lhs + getField @"temporaryCounter" rhs
         }
 
 instance Monoid Generator
   where
     mempty = Generator
         { labelCounter = 0
+        , temporaryCounter = 0
         }
 
 newtype Intermediate a = Intermediate
@@ -106,6 +119,16 @@ createLabel = do
         { labelCounter = getField @"labelCounter" generator + 1
         }
 
+createTemporary :: Intermediate Variable
+createTemporary = do
+    currentCounter <- Intermediate $ gets temporaryCounter
+    Intermediate $ modify' modifier
+    pure $ TempVariable currentCounter
+  where
+    modifier generator = generator
+        { temporaryCounter = getField @"temporaryCounter" generator + 1
+        }
+
 intermediate :: SymbolTable -> AST.Program -> HashMap AST.Identifier (Vector Quadruple)
 intermediate globalTable
     = fst
@@ -237,8 +260,8 @@ variableAccess localTable (AST.ArrayAccess access1 index1) Nothing (ArrayType _
     variableAccess localTable access1 (Just indexPlace) baseType statements
 variableAccess localTable (AST.ArrayAccess arrayAccess' arrayIndex) (Just baseIndex) (ArrayType arraySize baseType) statements = do
     (indexPlace, statements') <- expression localTable arrayIndex
-    let resultVariable = TempVariable
-        resultOperand = VariableOperand resultVariable
+    resultVariable <- createTemporary
+    let resultOperand = VariableOperand resultVariable
         indexCalculation = Vector.fromList
             [ ProductQuadruple (IntOperand $ fromIntegral arraySize) baseIndex resultVariable
             , AddQuadruple indexPlace resultOperand resultVariable
@@ -262,19 +285,19 @@ expression localTable = \case
         case variableAccess' of
             (AST.Identifier identifier, Nothing, statements) ->
                 pure (VariableOperand (Variable identifier), statements)
-            (AST.Identifier identifier, Just operand, statements) ->
-                let arrayAddress = TempVariable
-                    arrayStatement = ArrayQuadruple (Variable identifier) operand arrayAddress
-                 in pure
+            (AST.Identifier identifier, Just operand, statements) -> do
+                arrayAddress <- createTemporary
+                let arrayStatement = ArrayQuadruple (Variable identifier) operand arrayAddress
+                pure
                     ( VariableOperand arrayAddress
                     , Vector.snoc statements arrayStatement
                     )
     (AST.LiteralExpression literal') -> pure (literal literal', mempty)
     (AST.NegationExpression negation) -> do
         (operand, statements) <- expression localTable negation
-        let tempVariable = TempVariable
-            negationQuadruple = NegationQuadruple operand tempVariable
-         in pure
+        tempVariable <- createTemporary
+        let negationQuadruple = NegationQuadruple operand tempVariable
+        pure
             ( VariableOperand tempVariable
             , Vector.snoc statements negationQuadruple
             )
@@ -289,9 +312,9 @@ expression localTable = \case
     binaryExpression f lhs rhs = do
         (lhsOperand, lhsStatements) <- expression localTable lhs
         (rhsOperand, rhsStatements) <- expression localTable rhs
-        let tempVariable = TempVariable
-            newQuadruple = f lhsOperand rhsOperand tempVariable
-         in pure
+        tempVariable <- createTemporary
+        let newQuadruple = f lhsOperand rhsOperand tempVariable
+        pure
             ( VariableOperand tempVariable
             , Vector.snoc (lhsStatements <> rhsStatements) newQuadruple
             )