MisterChaos69/MiniJavaCompiler
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add missing typeCheckVariableDeclaration

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Maybe Fabian Noll aber vielleicht auch nicht. Ist ein bisschen ne Glaubenssache :) 2024-06-13 22:06:10 +02:00
parent 7e13b3fac3
commit f02226bca8
1 changed files with 22 additions and 8 deletions
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30
src/Typecheck.hs
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@ -2,7 +2,6 @@ module Typecheck where
import Data.List (find)
import Data.Maybe
import Ast
import Debug.Trace (trace)
typeCheckCompilationUnit :: CompilationUnit -> CompilationUnit
typeCheckCompilationUnit classes = map (`typeCheckClass` classes) classes
@ -10,13 +9,12 @@ typeCheckCompilationUnit classes = map (`typeCheckClass` classes) classes
typeCheckClass :: Class -> [Class] -> Class
typeCheckClass (Class className methods fields) classes =
let
-- Fields dont need to be added to the symtab because they are looked upon automatically under this if its not a declared local variable
-- TODO: Maybe remove method entries from the symbol table? I dont think we need them but if yes the next line would be
-- initalSymTab = ("this", className) : methodEntries
-- methodEntries = [(methodName, className) | MethodDeclaration _ methodName _ _ <- methods]
-- Fields and methods dont need to be added to the symtab because they are looked upon automatically under "this"
-- if its not a declared local variable. Also shadowing wouldnt be possible then.
initalSymTab = [("this", className)]
checkedMethods = map (\method -> typeCheckMethodDeclaration method initalSymTab classes) methods
in Class className checkedMethods fields
checkedFields = map (\field -> typeCheckVariableDeclaration field initalSymTab classes) fields
in Class className checkedMethods checkedFields
typeCheckMethodDeclaration :: MethodDeclaration -> [(Identifier, DataType)] -> [Class] -> MethodDeclaration
typeCheckMethodDeclaration (MethodDeclaration retType name params body) symtab classes =
@ -29,8 +27,24 @@ typeCheckMethodDeclaration (MethodDeclaration retType name params body) symtab c
then MethodDeclaration retType name params checkedBody
else error $ "Method Declaration: Return type mismatch in method " ++ name ++ ": expected " ++ retType ++ ", found " ++ bodyType
-- TODO: It could be that TypeCheckVariableDeclaration is missing. If it comes up -> just check wether the type is correct. The maybe expression needs to be
-- checked as well. Also if its a class type, check wether the class exists.
typeCheckVariableDeclaration :: VariableDeclaration -> [(Identifier, DataType)] -> [Class] -> VariableDeclaration
typeCheckVariableDeclaration (VariableDeclaration dataType identifier maybeExpr) symtab classes =
let
-- Ensure the type is valid (either a primitive type or a valid class name)
validType = dataType `elem` ["int", "boolean", "char"] || isUserDefinedClass dataType classes
-- Ensure no redefinition in the same scope
redefined = any ((== identifier) . snd) symtab
-- Type check the initializer expression if it exists
checkedExpr = fmap (\expr -> typeCheckExpression expr symtab classes) maybeExpr
exprType = fmap getTypeFromExpr checkedExpr
in case (validType, redefined, exprType) of
(False, _, _) -> error $ "Type '" ++ dataType ++ "' is not a valid type for variable '" ++ identifier ++ "'"
(_, True, _) -> error $ "Variable '" ++ identifier ++ "' is redefined in the same scope"
(_, _, Just t)
| t == "null" && isObjectType dataType -> VariableDeclaration dataType identifier checkedExpr
| t /= dataType -> error $ "Type mismatch in declaration of '" ++ identifier ++ "': expected " ++ dataType ++ ", found " ++ t
| otherwise -> VariableDeclaration dataType identifier checkedExpr
(_, _, Nothing) -> VariableDeclaration dataType identifier checkedExpr
-- ********************************** Type Checking: Expressions **********************************