Implement if statements with equality

lib/Language/Elna/Frontend/AST.hs

@@ -6,8 +6,8 @@ module Language.Elna.Frontend.AST
     , Statement(..)
     , TypeExpression(..)
     , VariableDeclaration(..)
-    {-, VariableAccess(..)
-    , Condition(..)-}
+    --, VariableAccess(..)
+    , Condition(..)
     , Expression(..)
     , Literal(..)
     ) where
@@ -67,8 +67,8 @@ instance Show TypeExpression
 
 data Statement
     = EmptyStatement
-    {-| AssignmentStatement VariableAccess Expression
     | IfStatement Condition Statement (Maybe Statement)
+    {-| AssignmentStatement VariableAccess Expression
     | WhileStatement Condition Statement -}
     | CompoundStatement [Statement]
     | CallStatement Identifier [Expression]
@@ -77,13 +77,13 @@ data Statement
 instance Show Statement
   where
     show EmptyStatement = ";"
-    {-show (AssignmentStatement lhs rhs) =
-        concat [show lhs, " := ", show rhs, ";"]
     show (IfStatement condition if' else') = concat
         [ "if (", show condition, ") "
         , show if'
         , maybe "" ((<> " else ") . show) else'
         ]
+    {-show (AssignmentStatement lhs rhs) =
+        concat [show lhs, " := ", show rhs, ";"]
     show (WhileStatement expression statement) =
         concat ["while (", show expression, ") ", show statement, ";"]-}
     show (CompoundStatement statements) =
@@ -143,22 +143,21 @@ instance Show VariableAccess
     show (VariableAccess variableName) = show variableName
     show (ArrayAccess arrayAccess elementIndex) =
         concat [show arrayAccess, "[", show elementIndex, "]"]
-
+-}
 data Condition
     = EqualCondition Expression Expression
-    | NonEqualCondition Expression Expression
-    | LessCondition Expression Expression
-    | GreaterCondition Expression Expression
-    | LessOrEqualCondition Expression Expression
-    | GreaterOrEqualCondition Expression Expression
+    -- | NonEqualCondition Expression Expression
+    -- | LessCondition Expression Expression
+    -- | GreaterCondition Expression Expression
+    -- | LessOrEqualCondition Expression Expression
+    -- | GreaterOrEqualCondition Expression Expression
     deriving Eq
 
 instance Show Condition
   where
     show (EqualCondition lhs rhs) = concat [show lhs, " = ", show rhs]
-    show (NonEqualCondition lhs rhs) = concat [show lhs, " # ", show rhs]
-    show (LessCondition lhs rhs) = concat [show lhs, " < ", show rhs]
-    show (GreaterCondition lhs rhs) = concat [show lhs, " > ", show rhs]
-    show (LessOrEqualCondition lhs rhs) = concat [show lhs, " <= ", show rhs]
-    show (GreaterOrEqualCondition lhs rhs) = concat [show lhs, " >= ", show rhs]
--}
+    -- show (NonEqualCondition lhs rhs) = concat [show lhs, " # ", show rhs]
+    -- show (LessCondition lhs rhs) = concat [show lhs, " < ", show rhs]
+    -- show (GreaterCondition lhs rhs) = concat [show lhs, " > ", show rhs]
+    -- show (LessOrEqualCondition lhs rhs) = concat [show lhs, " <= ", show rhs]
+    -- show (GreaterOrEqualCondition lhs rhs) = concat [show lhs, " >= ", show rhs]

lib/Language/Elna/Frontend/NameAnalysis.hs

@@ -160,17 +160,37 @@ statement globalTable (AST.CallStatement name arguments)
     >> traverse_ (expression globalTable) arguments
 statement globalTable (AST.CompoundStatement statements) =
     traverse_ (statement globalTable) statements
-{- statement globalTable (AST.AssignmentStatement lvalue rvalue)
-    = variableAccess globalTable lvalue
-    >> expression globalTable rvalue
 statement globalTable (AST.IfStatement ifCondition ifStatement elseStatement)
     = condition globalTable ifCondition
     >> statement globalTable ifStatement
     >> maybe (pure ()) (statement globalTable) elseStatement
-statement globalTable (AST.WhileStatement whileCondition loop)
-    = condition globalTable whileCondition
-    >> statement globalTable loop
+-- statement globalTable (AST.AssignmentStatement lvalue rvalue)
+--    = variableAccess globalTable lvalue
+--    >> expression globalTable rvalue
+--statement globalTable (AST.WhileStatement whileCondition loop)
+--    = condition globalTable whileCondition
+--    >> statement globalTable loop
 
+condition :: SymbolTable -> AST.Condition -> NameAnalysis ()
+condition globalTable (AST.EqualCondition lhs rhs)
+    = expression globalTable lhs
+    >> expression globalTable rhs
+--condition globalTable (AST.NonEqualCondition lhs rhs)
+--    = expression globalTable lhs
+--    >> expression globalTable rhs
+--condition globalTable (AST.LessCondition lhs rhs)
+--    = expression globalTable lhs
+--    >> expression globalTable rhs
+--condition globalTable (AST.GreaterCondition lhs rhs)
+--    = expression globalTable lhs
+--    >> expression globalTable rhs
+--condition globalTable (AST.LessOrEqualCondition lhs rhs)
+--    = expression globalTable lhs
+--    >> expression globalTable rhs
+--condition globalTable (AST.GreaterOrEqualCondition lhs rhs)
+--    = expression globalTable lhs
+--    >> expression globalTable rhs
+{-
 variableAccess :: SymbolTable -> AST.VariableAccess -> NameAnalysis ()
 variableAccess globalTable (AST.ArrayAccess arrayExpression indexExpression)
     = variableAccess globalTable arrayExpression
@@ -178,26 +198,6 @@ variableAccess globalTable (AST.ArrayAccess arrayExpression indexExpression)
 variableAccess globalTable (AST.VariableAccess identifier) =
     checkSymbol globalTable identifier
 
-condition :: SymbolTable -> AST.Condition -> NameAnalysis ()
-condition globalTable (AST.EqualCondition lhs rhs)
-    = expression globalTable lhs
-    >> expression globalTable rhs
-condition globalTable (AST.NonEqualCondition lhs rhs)
-    = expression globalTable lhs
-    >> expression globalTable rhs
-condition globalTable (AST.LessCondition lhs rhs)
-    = expression globalTable lhs
-    >> expression globalTable rhs
-condition globalTable (AST.GreaterCondition lhs rhs)
-    = expression globalTable lhs
-    >> expression globalTable rhs
-condition globalTable (AST.LessOrEqualCondition lhs rhs)
-    = expression globalTable lhs
-    >> expression globalTable rhs
-condition globalTable (AST.GreaterOrEqualCondition lhs rhs)
-    = expression globalTable lhs
-    >> expression globalTable rhs
-
 enter :: Identifier -> Info -> SymbolTable -> NameAnalysis SymbolTable
 enter identifier info table
     = maybe (identifierAlreadyDefinedError identifier) pure

lib/Language/Elna/Frontend/Parser.hs

@@ -16,8 +16,8 @@ import Language.Elna.Frontend.AST
     , Statement(..)
     , TypeExpression(..)
     , VariableDeclaration(..)
-    {-, VariableAccess(..)
-    , Condition(..)-}
+    --, VariableAccess(..)
+    , Condition(..)
     , Expression(..)
     , Literal(..)
     )
@@ -97,7 +97,7 @@ variableAccessP = do
     identifier <- identifierP
     indices <- many $ bracketsP expressionP
     pure $ foldr (flip ArrayAccess) (VariableAccess identifier) indices
-
+-}
 conditionP :: Parser Condition
 conditionP = do
     lhs <- expressionP
@@ -105,14 +105,14 @@ conditionP = do
     conditionCons lhs <$> expressionP
   where
     comparisonOperator =
-        [ symbol "<" >> pure LessCondition
-        , symbol "<=" >> pure LessOrEqualCondition
-        , symbol ">" >> pure GreaterCondition
-        , symbol ">=" >> pure GreaterOrEqualCondition
-        , symbol "=" >> pure EqualCondition
-        , symbol "#" >> pure NonEqualCondition
+        --, symbol "<" >> pure LessCondition
+        --, symbol "<=" >> pure LessOrEqualCondition
+        --, symbol ">" >> pure GreaterCondition
+        --, symbol ">=" >> pure GreaterOrEqualCondition
+        [ symbol "=" >> pure EqualCondition
+        --, symbol "#" >> pure NonEqualCondition
         ]
--}
+
 symbol :: Text -> Parser Text
 symbol = Lexer.symbol space
 
@@ -182,22 +182,22 @@ procedureDeclarationP = procedureCons
 statementP :: Parser Statement
 statementP
     = EmptyStatement <$ semicolonP
+    <|> ifElseP
     {-<|> CompoundStatement <$> blockP (many statementP)
     <|> try assignmentP
-    <|> try ifElseP
     <|> try whileP -}
-    <|> try callP
+    <|> callP
     <?> "statement"
   where
     callP = CallStatement
         <$> identifierP
         <*> parensP (sepBy expressionP commaP)
         <* semicolonP
-    {-ifElseP = IfStatement
+    ifElseP = IfStatement
         <$> (symbol "if" *> parensP conditionP)
         <*> statementP
         <*> optional (symbol "else" *> statementP)
-    whileP = WhileStatement
+    {-whileP = WhileStatement
         <$> (symbol "while" *> parensP conditionP)
         <*> statementP
     assignmentP = AssignmentStatement