Implement the while loop

lib/Language/Elna/Frontend/AST.hs

@@ -71,7 +71,7 @@ data Statement
     = EmptyStatement
     | IfStatement Condition Statement (Maybe Statement)
     | AssignmentStatement VariableAccess Expression
-    -- | WhileStatement Condition Statement
+    | WhileStatement Condition Statement
     | CompoundStatement [Statement]
     | CallStatement Identifier [Expression]
     deriving Eq
@@ -86,8 +86,8 @@ instance Show Statement
         ]
     show (AssignmentStatement lhs rhs) =
         concat [show lhs, " := ", show rhs, ";"]
-    {-show (WhileStatement expression statement) =
-        concat ["while (", show expression, ") ", show statement, ";"]-}
+    show (WhileStatement expression statement) =
+        concat ["while (", show expression, ") ", show statement, ";"]
     show (CompoundStatement statements) =
         concat ["{\n", unlines (show <$> statements), " }"]
     show (CallStatement name parameters) = show name <> "("

lib/Language/Elna/Frontend/NameAnalysis.hs

@@ -175,9 +175,9 @@ statement globalTable (AST.IfStatement ifCondition ifStatement elseStatement)
 statement globalTable (AST.AssignmentStatement lvalue rvalue)
     = variableAccess globalTable lvalue
     >> expression globalTable rvalue
---statement globalTable (AST.WhileStatement whileCondition loop)
---    = condition globalTable whileCondition
---    >> statement globalTable loop
+statement globalTable (AST.WhileStatement whileCondition loop)
+    = condition globalTable whileCondition
+    >> statement globalTable loop
 
 condition :: SymbolTable -> AST.Condition -> NameAnalysis ()
 condition globalTable (AST.EqualCondition lhs rhs)

lib/Language/Elna/Frontend/Parser.hs

@@ -188,7 +188,7 @@ statementP
     <|> ifElseP
     <|> CompoundStatement <$> blockP (many statementP)
     <|> try assignmentP
-    -- <|> try whileP
+    <|> try whileP
     <|> callP
     <?> "statement"
   where
@@ -200,9 +200,9 @@ statementP
         <$> (symbol "if" *> parensP conditionP)
         <*> statementP
         <*> optional (symbol "else" *> statementP)
-    {-whileP = WhileStatement
+    whileP = WhileStatement
         <$> (symbol "while" *> parensP conditionP)
-        <*> statementP -}
+        <*> statementP
     assignmentP = AssignmentStatement
         <$> variableAccessP
         <* symbol ":="

lib/Language/Elna/Frontend/TypeAnalysis.hs

@@ -101,11 +101,11 @@ statement globalTable = \case
             $ TypeAnalysis $ lift $ throwE $ InvalidConditionTypeError lhsType
         unless (rhsType == intType)
             $ TypeAnalysis $ lift $ throwE $ InvalidConditionTypeError rhsType
-    {- AST.WhileStatement whileCondition whileStatement -> do
+    AST.WhileStatement whileCondition whileStatement -> do
         conditionType <- condition globalTable whileCondition
         unless (conditionType == booleanType)
             $ TypeAnalysis $ lift $ throwE $ InvalidConditionTypeError conditionType
-        statement globalTable whileStatement -}
+        statement globalTable whileStatement
     AST.IfStatement ifCondition ifStatement elseStatement -> do
         conditionType <- condition globalTable ifCondition
         unless (conditionType == booleanType)