| ////////////////////// |
| * Licensed 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. |
| ////////////////////// |
| |
| [[core-api-value,ValueComposite]] |
| = ValueComposite = |
| Usage of value objects is one of the most ignored and best return-on-investment the programmer can do. Values are |
| immutable and can be compared by value instead of memory reference. Concurrency is suddenly not an issue, since either |
| the value exists or it doesn't, no need for synchronization. Values are typically very easy to test and very robust to |
| refactoring. |
| |
| Polygene™ defines values as a primary meta type through the ValueComposite, as we think the benefits of values are great. |
| The ValueComposite is very light-weight compared to the EntityComposite, and its value can still be persisted as part |
| of an EntityComposite via a Property. |
| |
| The characteristics of a ValueComposite compared to other Composite meta types are; |
| |
| * It is Immutable. |
| * Its equals/hashCode works on both the descriptor and the values of the ValueComposite. |
| * Can be used as Property types. |
| * Can be serialized and deserialized, see <<core-api-serialization>>. |
