Made method mutability part of signature and method selection

IDEHelper/Compiler/BfAst.h

@@ -738,6 +738,8 @@ public:
 			break;
 		}
 	}
+
+	bool CanModify() const;
 };
 
 #define BF_AST_TYPE(name, TBase) \

IDEHelper/Compiler/BfExprEvaluator.cpp

@@ -1015,6 +1015,7 @@ void BfMethodMatcher::CompareMethods(BfMethodInstance* prevMethodInstance, BfTyp
 	auto activeDef = mModule->GetActiveTypeDef();
 	RETURN_BETTER_OR_WORSE(newMethodDef->mDeclaringType == activeDef, prevMethodDef->mDeclaringType == activeDef);
 	RETURN_BETTER_OR_WORSE(newMethodDef->mDeclaringType->IsExtension(), prevMethodDef->mDeclaringType->IsExtension());
+	RETURN_BETTER_OR_WORSE(newMethodDef->mIsMutating, prevMethodDef->mIsMutating);
 
 	RETURN_RESULTS;
 }
@@ -1437,6 +1438,13 @@ bool BfMethodMatcher::CheckMethod(BfTypeInstance* targetTypeInstance, BfTypeInst
 	else if (needInferGenericParams)
 		genericArgumentsSubstitute = &mCheckMethodGenericArguments;
 	
+	if ((checkMethod->mIsMutating) && (targetTypeInstance != NULL) && (targetTypeInstance->IsValueType()) &&
+		((mTarget.IsReadOnly()) || (!mTarget.IsAddr())) &&
+		(!targetTypeInstance->IsValuelessType()))
+	{
+		goto NoMatch;
+	}
+
 	if (mSkipImplicitParams)
 	{
 		//paramOfs = methodInstance->GetImplicitParamCount();
@@ -4200,7 +4208,7 @@ BfTypedValue BfExprEvaluator::LookupField(BfAstNode* targetSrc, BfTypedValue tar
 						{
 							if (curCheckType->mTypeDef->HasAutoProperty(propertyDeclaration))
 							{								
-								bool hasSetter = GetPropertyMethodDef(mPropDef, BfMethodType_PropertySetter, BfCheckedKind_NotSet) != NULL;
+								bool hasSetter = GetPropertyMethodDef(mPropDef, BfMethodType_PropertySetter, BfCheckedKind_NotSet, mPropTarget) != NULL;
 								auto autoFieldName = curCheckType->mTypeDef->GetAutoPropertyName(propertyDeclaration);
 								auto result = LookupField(targetSrc, target, autoFieldName, BfLookupFieldFlag_IgnoreProtection);
 								if (result)
@@ -14845,14 +14853,54 @@ void BfExprEvaluator::Visit(BfInvocationExpression* invocationExpr)
 		mResult = cascadeValue;
 }
 
-BfMethodDef* BfExprEvaluator::GetPropertyMethodDef(BfPropertyDef* propDef, BfMethodType methodType, BfCheckedKind checkedKind)
+BfMethodDef* BfExprEvaluator::GetPropertyMethodDef(BfPropertyDef* propDef, BfMethodType methodType, BfCheckedKind checkedKind, BfTypedValue propTarget)
 {
+	bool allowMut = (propTarget) && (!propTarget.mType->IsValueType() || propTarget.CanModify());
+
+	int bestPri = -1000;
 	BfMethodDef* matchedMethod = NULL;
+
+	for (auto methodDef : propDef->mMethods)
+	{
+		if (methodDef->mMethodType != methodType)
+			continue;
+
+		int curPri = 0;		
+
+		if (methodDef->mCheckedKind == checkedKind)
+		{
+			curPri = 5;
+		}
+		else if ((checkedKind == BfCheckedKind_NotSet) && (methodDef->mCheckedKind == mModule->GetDefaultCheckedKind()))
+			curPri = 3;
+		else
+			curPri = 1;
+
+		if (methodDef->mIsMutating)
+		{
+			if (allowMut)
+				curPri++;
+			else
+				curPri -= 10;
+		}
+
+		if (curPri > bestPri)
+		{
+			bestPri = curPri;
+			matchedMethod = methodDef;
+		}
+	}
+
+	return matchedMethod;
+
+	/*BfMethodDef* matchedMethod = NULL;
 	BfMethodDef* backupMethod = NULL;
 	for (auto methodDef : propDef->mMethods)
 	{
 		if (methodDef->mMethodType != methodType)
 			continue;
+				
+
 		if (methodDef->mCheckedKind == checkedKind)
 		{
 			matchedMethod = methodDef;
@@ -14865,7 +14913,7 @@ BfMethodDef* BfExprEvaluator::GetPropertyMethodDef(BfPropertyDef* propDef, BfMet
 	}
 	if (matchedMethod == NULL)
 		matchedMethod = backupMethod;
-	return matchedMethod;
+	return matchedMethod;*/
 }
 
 BfModuleMethodInstance BfExprEvaluator::GetPropertyMethodInstance(BfMethodDef* methodDef)
@@ -15084,7 +15132,7 @@ BfTypedValue BfExprEvaluator::GetResult(bool clearResult, bool resolveGenericTyp
 			SetAndRestoreValue<BfFunctionBindResult*> prevFunctionBindResult(mFunctionBindResult, NULL); 
 			SetAndRestoreValue<BfAstNode*> prevDeferCallRef(mDeferCallRef, NULL);			
 
-			BfMethodDef* matchedMethod = GetPropertyMethodDef(mPropDef, BfMethodType_PropertyGetter, mPropCheckedKind);
+			BfMethodDef* matchedMethod = GetPropertyMethodDef(mPropDef, BfMethodType_PropertyGetter, mPropCheckedKind, mPropTarget);
 			if (matchedMethod == NULL)
 			{
 				mModule->Fail("Property has no getter", mPropSrc);
@@ -15404,8 +15452,7 @@ bool BfExprEvaluator::CheckModifyResult(BfTypedValue typedVal, BfAstNode* refNod
 		return true;
 	}
 
-	bool canModify = (((typedVal.IsAddr()) || (typedVal.mType->IsValuelessType())) &&
+	bool canModify = typedVal.CanModify();
-		(!typedVal.IsReadOnly()));
 
 	if (localVar != NULL)
 	{
@@ -15777,7 +15824,7 @@ void BfExprEvaluator::PopulateDeferrredTupleAssignData(BfTupleExpression* tupleE
 					propTypeInst = pointerType->mElementType->ToTypeInstance();
 				}
 				
-				auto setMethod = GetPropertyMethodDef(exprEvaluator->mPropDef, BfMethodType_PropertySetter, mPropCheckedKind);
+				auto setMethod = GetPropertyMethodDef(exprEvaluator->mPropDef, BfMethodType_PropertySetter, mPropCheckedKind, mPropTarget);
 				if (setMethod != NULL)
 				{
 					auto methodInstance = mModule->GetMethodInstance(propTypeInst, setMethod, BfTypeVector());
@@ -15785,7 +15832,7 @@ void BfExprEvaluator::PopulateDeferrredTupleAssignData(BfTupleExpression* tupleE
 				}
 				else 
 				{
-					auto getMethod = GetPropertyMethodDef(exprEvaluator->mPropDef, BfMethodType_PropertyGetter, mPropCheckedKind);
+					auto getMethod = GetPropertyMethodDef(exprEvaluator->mPropDef, BfMethodType_PropertyGetter, mPropCheckedKind, mPropTarget);
 					if (getMethod != NULL)
 					{
 						auto methodInstance = mModule->GetMethodInstance(propTypeInst, getMethod, BfTypeVector());
@@ -15948,7 +15995,7 @@ void BfExprEvaluator::PerformAssignment(BfAssignmentExpression* assignExpr, bool
 		auto propDef = mPropDef;
 		auto propTarget = mPropTarget;
 
-		auto setMethod = GetPropertyMethodDef(mPropDef, BfMethodType_PropertySetter, mPropCheckedKind);
+		auto setMethod = GetPropertyMethodDef(mPropDef, BfMethodType_PropertySetter, mPropCheckedKind, mPropTarget);
 		if (setMethod == NULL)
 		{
 			// Allow for a ref return on the getter to be used if a setter is not available
@@ -17306,6 +17353,7 @@ void BfExprEvaluator::Visit(BfIndexerExpression* indexerExpr)
 							continue;
 
 						methodMatcher.mCheckedKind = checkedKind;
+						methodMatcher.mTarget = target;
 						methodMatcher.CheckMethod(startCheckTypeInst, curCheckType, checkMethod, false);						
 
 						if ((methodMatcher.mBestMethodDef == checkMethod) ||
@@ -18191,7 +18239,7 @@ void BfExprEvaluator::PerformUnaryOperation_OnResult(BfExpression* unaryOpExpr,
 
 	if (writeToProp)
 	{
-		auto setMethod = GetPropertyMethodDef(propDef, BfMethodType_PropertySetter, mPropCheckedKind);
+		auto setMethod = GetPropertyMethodDef(propDef, BfMethodType_PropertySetter, mPropCheckedKind, mPropTarget);
 		if (setMethod == NULL)
 		{
 			mModule->Fail("Property has no setter", propSrc);

IDEHelper/Compiler/BfExprEvaluator.h

@@ -348,7 +348,7 @@ public:
 	void ResolveArgValues(BfResolvedArgs& resolvedArgs, BfResolveArgFlags flags = BfResolveArgFlag_None);
 	BfAllocTarget ResolveAllocTarget(BfAstNode* newNode, BfTokenNode*& newToken, BfCustomAttributes** outCustomAttributes = NULL);
 	BfTypedValue ResolveArgValue(BfResolvedArg& resolvedArg, BfType* wantType, BfTypedValue* receivingValue = NULL, BfParamKind paramKind = BfParamKind_Normal);
-	BfMethodDef* GetPropertyMethodDef(BfPropertyDef* propDef, BfMethodType methodType, BfCheckedKind checkedKind);
+	BfMethodDef* GetPropertyMethodDef(BfPropertyDef* propDef, BfMethodType methodType, BfCheckedKind checkedKind, BfTypedValue propTarget);
 	BfModuleMethodInstance GetPropertyMethodInstance(BfMethodDef* methodDef);
 	void CheckPropFail(BfMethodDef* propMethodDef, BfMethodInstance* methodInstance, bool checkProt);
 	bool HasResult();

IDEHelper/Compiler/BfModule.cpp

@@ -20846,6 +20846,7 @@ void BfModule::DoMethodDeclaration(BfMethodDeclaration* methodDeclaration, bool
 
 					if (((checkMethodInstance->mChainType == BfMethodChainType_None) || (checkMethodInstance->mChainType == BfMethodChainType_ChainHead)) &&						
 						(checkMethodInstance->GetExplicitInterface() == methodInstance->GetExplicitInterface()) &&
+						(checkMethod->mIsMutating == methodDef->mIsMutating) &&
 						(CompareMethodSignatures(checkMethodInstance, mCurMethodInstance)))
 					{							
 						bool canChain = false;

IDEHelper/Compiler/BfResolvedTypeUtils.cpp

@@ -56,6 +56,11 @@ bool BfTypedValue::IsValuelessType() const
 	return mType->IsValuelessType();
 }
 
+bool BfTypedValue::CanModify() const
+{	
+	return (((IsAddr()) || (mType->IsValuelessType())) && (!IsReadOnly()));	
+}
+
 //////////////////////////////////////////////////////////////////////////
 
 bool BfDependencyMap::AddUsedBy(BfType* dependentType, BfDependencyMap::DependencyFlags flags)

IDEHelper/Tests/src/Indexers.bf

@@ -31,6 +31,24 @@ namespace Tests
 
 		}
 
+		struct StructA
+		{
+			int mA;
+
+			public int this[int index]
+			{
+				get
+				{
+					return 1;
+				}
+
+				get mut
+				{
+					return 2;
+				}
+			}
+		}
+
 		[Test]
 		public static void Hey()
 		{
@@ -43,6 +61,11 @@ namespace Tests
 			Test.Assert(value == 234);
 			value = ca[0];
 			Test.Assert(value == 234);
+
+			StructA sa = default;
+			let sa2 = sa;
+			Test.Assert(sa[0] == 2);
+			Test.Assert(sa2[0] == 1);
 		}
 	}
 }

IDEHelper/Tests/src/Properties.bf

@@ -36,8 +36,35 @@ namespace Tests
 		{
 			public StructA B { get; }
 
+			public int C => 123;
+			[SkipCall]
+			public int D => 123;
+
+			public int E
+			{
+				get
+				{
+					return 1;
+				}
+
+				get mut
+				{
+					return 2;
+				}
+			}
+
 			int mZ = 9;
 
+			public int GetVal()
+			{
+				return 3;
+			}
+
+			public int GetVal() mut
+			{
+				return 4;
+			}
+
 			public this()
 			{
 				B = .();
@@ -73,6 +100,15 @@ namespace Tests
 			sa = sb.B;
 			Test.Assert(sa.mA == 222);
 
+			StructC sc = default;
+			Test.Assert(sc.C == 123);
+			Test.Assert(sc.D == 0);
+			let sc2 = sc;
+			Test.Assert(sc.E == 2);
+			Test.Assert(sc.GetVal() == 4);
+			Test.Assert(sc2.E == 1);
+			Test.Assert(sc2.GetVal() == 3);
+
 			ClassB cb = scope .();
 			sa = cb.B;
 			Test.Assert(sa.mA == 0);