Exemplo n.º 1
0
//while-condition -> expression  declaration
ExpressionPtr Parser::parseConditionExpression()
{
    Token token;
    expect_next(token);
    if(token.type == TokenType::Identifier && token.identifier.keyword != Keyword::_)
    {
        Keyword::T keyword = token.identifier.keyword;
        tassert(token, keyword == Keyword::Var || keyword == Keyword::Let, Errors::E_EXPECTED_EXPRESSION_VAR_OR_LET_IN_A_CONDITION_1, L"if");
        ValueBindingPatternPtr value = nodeFactory->createValueBindingPattern(token.state);
        value->setReadOnly(keyword == Keyword::Let);
        PatternPtr binding = parsePattern();
        value->setBinding(binding);
        if(binding->getNodeType() == NodeType::TypedPattern)
        {
            TypedPatternPtr tpattern = std::static_pointer_cast<TypedPattern>(binding);
            value->setBinding(tpattern->getPattern());
            value->setDeclaredType(tpattern->getDeclaredType());
        }
        if (!match(L"=", token))
        {
            tassert(token, false, Errors::E_VARIABLE_BINDING_IN_A_CONDITION_REQUIRES_AN_INITIALIZER);
        }
        AssignmentPtr assignment = nodeFactory->createAssignment(token.state);
        ExpressionPtr expr = parseExpression();
        assignment->setLHS(value);
        assignment->setRHS(expr);
        return assignment;
    }
    else
    {
        restore(token);
        return parseExpression();
    }
}
void SemanticAnalyzer::visitValueBinding(const ValueBindingPtr& node)
{
    PatternPtr name = node->getName();
    //tuple was already exploded in declaration analyzer
    if(name->getNodeType() == NodeType::Tuple)
    {
        validateTupleTypeDeclaration(node);
    }
    if (name->getNodeType() != NodeType::Identifier)
        return;
    if(node->getOwner()->isReadOnly() && !node->getInitializer() && ctx->currentType == nullptr)
    {
        error(node, Errors::E_LET_REQUIRES_INITIALIZER);
        return;
    }
    //handle type inference for temporary variable
    if(node->isTemporary() && node->getInitializer())
    {
        //temporary variable always has an initializer
        TypePtr initializerType;
        TypePtr declaredType = node->getType();

        SCOPED_SET(ctx->contextualType, declaredType);
        node->getInitializer()->accept(this);
        initializerType = node->getInitializer()->getType();
        assert(initializerType != nullptr);

        if(declaredType)
        {
            //it has both type definition and initializer, then we need to check if the initializer expression matches the type annotation
            if(!initializerType->canAssignTo(declaredType))
            {
                error(node, Errors::E_CANNOT_CONVERT_EXPRESSION_TYPE_2, initializerType->toString(), declaredType->toString());
                return;
            }
        }
        else
        {
            node->setType(initializerType);
        }
    }
    

    //add implicitly constructor for Optional
    IdentifierPtr id = static_pointer_cast<Identifier>(node->getName());
    SymbolScope* currentScope = symbolRegistry->getCurrentScope();


    TypePtr declaredType = node->getType() ? node->getType() : lookupType(node->getDeclaredType());
    SCOPED_SET(ctx->contextualType, declaredType);
    if(!declaredType && !node->getInitializer())
    {
        error(node, Errors::E_TYPE_ANNOTATION_MISSING_IN_PATTERN);
        return;
    }
    SymbolPtr sym = currentScope->lookup(id->getIdentifier());
    assert(sym != nullptr);
    SymbolPlaceHolderPtr placeholder = std::dynamic_pointer_cast<SymbolPlaceHolder>(sym);
    assert(placeholder != nullptr);
    if(declaredType)
    {
        placeholder->setType(declaredType);
    }
    ExpressionPtr initializer = node->getInitializer();
    if(initializer)
    {
        placeholder->setFlags(SymbolFlagInitializing, true);
        ExpressionPtr initializer = transformExpression(declaredType, node->getInitializer());
        node->setInitializer(initializer);
        TypePtr actualType = initializer->getType();
        assert(actualType != nullptr);
        if(declaredType)
        {
            if(!Type::equals(actualType, declaredType) && !canConvertTo(initializer, declaredType))
            {
                error(initializer, Errors::E_CANNOT_CONVERT_EXPRESSION_TYPE_2, actualType->toString(), declaredType->toString());
                return;
            }
        }

        if(!declaredType)
            placeholder->setType(actualType);
    }
    assert(placeholder->getType() != nullptr);
    placeholder->setFlags(SymbolFlagInitializing, false);
    //optional type always considered initialized, compiler will make it has a default value nil
    TypePtr symbolType = sym->getType();
    GlobalScope* global = symbolRegistry->getGlobalScope();
    if(initializer || global->isOptional(symbolType) || global->isImplicitlyUnwrappedOptional(symbolType))
        markInitialized(placeholder);

    if (initializer)
        placeholder->setFlags(SymbolFlagHasInitializer, true);
    if(node->isTemporary())
    {
        placeholder->setFlags(SymbolFlagTemporary, true);
        markInitialized(placeholder);
    }

    if(!node->isTemporary())
    {
        //check access control level
        DeclarationType decl = ctx->currentType ? DeclarationTypeProperty : DeclarationTypeVariable;
        declarationAnalyzer->verifyAccessLevel(node->getOwner(), placeholder->getType(), decl, ComponentTypeType);
    }
    if(ctx->currentType && ctx->currentType->getCategory() == Type::Protocol)
    {
        error(node, Errors::E_PROTOCOL_VAR_MUST_BE_COMPUTED_PROPERTY_1);
    }
}
void SemanticAnalyzer::validateTupleTypeDeclaration(const PatternPtr& name, const TypePtr& declType, const TypePtr& initType)
{
    switch(name->getNodeType())
    {
        case NodeType::Identifier:
        {
            if(initType && declType && !initType->canAssignTo(declType))
            {
                error(name, Errors::E_CANNOT_CONVERT_EXPRESSION_TYPE_2, initType->toString(), declType->toString());
            }
            break;
        }
        case NodeType::TypedPattern:
        {
            TypedPatternPtr pat = static_pointer_cast<TypedPattern>(name);
            assert(pat->getDeclaredType());
            TypePtr nameType = lookupType(pat->getDeclaredType());
            assert(nameType != nullptr);
            if(declType && !Type::equals(nameType, declType))
            {
                error(name, Errors::E_TYPE_ANNOTATION_DOES_NOT_MATCH_CONTEXTUAL_TYPE_A_1, declType->toString());
                abort();
                return;
            }

            break;
        }
        case NodeType::Tuple:
        {
            TuplePtr tuple = static_pointer_cast<Tuple>(name);
            if(declType)
            {
                if((declType->getCategory() != Type::Tuple) || (tuple->numElements() != declType->numElementTypes()))
                {
                    error(name, Errors::E_TYPE_ANNOTATION_DOES_NOT_MATCH_CONTEXTUAL_TYPE_A_1, declType->toString());
                    abort();
                    return;
                }
            }
            int elements = tuple->numElements();
            for(int i = 0; i < elements; i++)
            {
                PatternPtr element = tuple->getElement(i);
                TypePtr elementDecl = declType ? declType->getElementType(i) : nullptr;
                TypePtr elementInit = initType ? initType->getElementType(i) : nullptr;
                validateTupleTypeDeclaration(element, elementDecl, elementInit);
            }
            break;
        }
        case NodeType::ValueBindingPattern:
            break;
        case NodeType::EnumCasePattern:
        {
            
            break;
        }
        case NodeType::TypeCase:
        case NodeType::TypeCheck:
        default:
            error(name, Errors::E_EXPECT_TUPLE_OR_IDENTIFIER);
            break;
    }
    
}