| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.cassandra.cql3; |
| |
| import java.util.Collection; |
| |
| public interface AssignmentTestable |
| { |
| /** |
| * @return whether this object can be assigned to the provided receiver. We distinguish |
| * between 3 values: |
| * - EXACT_MATCH if this object is exactly of the type expected by the receiver |
| * - WEAKLY_ASSIGNABLE if this object is not exactly the expected type but is assignable nonetheless |
| * - NOT_ASSIGNABLE if it's not assignable |
| * Most caller should just call the isAssignable() method on the result, though functions have a use for |
| * testing "strong" equality to decide the most precise overload to pick when multiple could match. |
| */ |
| public TestResult testAssignment(String keyspace, ColumnSpecification receiver); |
| |
| public enum TestResult |
| { |
| EXACT_MATCH, WEAKLY_ASSIGNABLE, NOT_ASSIGNABLE; |
| |
| public boolean isAssignable() |
| { |
| return this != NOT_ASSIGNABLE; |
| } |
| |
| public boolean isExactMatch() |
| { |
| return this == EXACT_MATCH; |
| } |
| |
| // Test all elements of toTest for assignment. If all are exact match, return exact match. If any is not assignable, |
| // return not assignable. Otherwise, return weakly assignable. |
| public static TestResult testAll(String keyspace, ColumnSpecification receiver, Collection<? extends AssignmentTestable> toTest) |
| { |
| TestResult res = EXACT_MATCH; |
| for (AssignmentTestable rt : toTest) |
| { |
| if (rt == null) |
| { |
| res = WEAKLY_ASSIGNABLE; |
| continue; |
| } |
| |
| TestResult t = rt.testAssignment(keyspace, receiver); |
| if (t == NOT_ASSIGNABLE) |
| return NOT_ASSIGNABLE; |
| |
| if (t == WEAKLY_ASSIGNABLE) |
| res = WEAKLY_ASSIGNABLE; |
| } |
| return res; |
| } |
| } |
| } |