Method VisitMemberExpression

Source/SpireCore/CodeGenerator.cpp:1087–1145

				return expr;
			}
			virtual RefPtr<ExpressionSyntaxNode> VisitMemberExpression(MemberExpressionSyntaxNode * expr) override
			{
				RefPtr<Object> refObj;
				if (expr->Tags.TryGetValue("ComponentReference", refObj))
				{
					if (auto refComp = refObj.As<StringObject>())
					{
						ILOperand * op;
						if (variables.TryGetValue(refComp->Content, op))
							PushStack(op);
						else
							throw InvalidProgramException("referencing undefined component/variable. probable cause: unchecked circular reference.");
					}
				}
				else
				{
					expr->BaseExpression->Access = expr->Access;
					expr->BaseExpression->Accept(this);
					auto base = PopStack();
					auto generateSingleMember = [&](char memberName)
					{
						int idx = 0;
						if (memberName == 'y' || memberName == 'g')
							idx = 1;
						else if (memberName == 'z' || memberName == 'b')
							idx = 2;
						else if (memberName == 'w' || memberName == 'a')
							idx = 3;

						GenerateIndexExpression(base, result.Program->ConstantPool->CreateConstant(idx),
							expr->Access == ExpressionAccess::Read);
					};
					if (expr->BaseExpression->Type->IsVectorType())
					{
						if (expr->MemberName.Length() == 1)
						{
							generateSingleMember(expr->MemberName[0]);
						}
						else
						{
							auto rs = new SwizzleInstruction();
							rs->Type = TranslateExpressionType(expr->Type.Ptr());
							rs->SwizzleString = expr->MemberName;
							rs->Operand = base;
							codeWriter.Insert(rs);
							PushStack(rs);
						}
					}
					else if (expr->BaseExpression->Type->IsStruct())
					{
						int id = expr->BaseExpression->Type->AsBasicType()->structDecl->FindFieldIndex(expr->MemberName);
						GenerateIndexExpression(base, result.Program->ConstantPool->CreateConstant(id),
							expr->Access == ExpressionAccess::Read);
					}
					else
						throw NotImplementedException("member expression codegen");
				}
				return expr;