View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0003511 | 10000-003: Address Space | Spec | public | 2016-08-18 11:15 | 2017-01-12 17:04 |
| Reporter | BjarneBostrom | Assigned To | jeffhardingabb | ||
| Priority | normal | Severity | minor | Reproducibility | N/A |
| Status | closed | Resolution | fixed | ||
| Summary | 0003511: Subtyping Unions needs clarification | ||||
| Description | The spec ver 1.03 part 3 section 8.42 states "All DataTypes inheriting from this DataType have special handling for the encoding as defined in Part 6. All union DataTypes shall inherit from this DataType." To me it is not clear is it possible to subtype an existing Union. Technically this would be possible (e.g. in java where there is no language level support for unions so it would be implemented e.g. as Object), however to my knowledge extending unions is not possible in languages that support them natively, therefore the spec should clarify that only direct subtypes of Union are allowed. | ||||
| Tags | No tags attached. | ||||
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Another clarification would be needed that is it allowed to read the value from an union as different type than it was put there, e.g. c-style typecasting? (As a note this would make implementing unions in programming languages that do not support them extremely or completely impossible). |
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Discussed in telecon. We agree there is no practical value in allowing subtypes of Unions. Clarify in the spec. |
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It is not possible to subtype Unions. This means all Union types must inherit directly from the base abstract DataType 'Union'. Clarifying text has been added to Part 3 section 8.42 to state the requirement for direct inheritance. |
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agreed to changes in telecon. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2016-08-18 11:15 | BjarneBostrom | New Issue | |
| 2016-08-22 12:44 | BjarneBostrom | Note Added: 0007147 | |
| 2016-08-30 15:33 | Jim Luth | Assigned To | => Wolfgang Mahnke |
| 2016-08-30 15:33 | Jim Luth | Status | new => assigned |
| 2016-08-30 15:33 | Jim Luth | Note Added: 0007160 | |
| 2016-11-29 14:10 | Jim Luth | Assigned To | Wolfgang Mahnke => jeffhardingabb |
| 2016-12-16 17:31 | jeffhardingabb | Note Added: 0007630 | |
| 2016-12-16 17:31 | jeffhardingabb | Status | assigned => resolved |
| 2016-12-16 17:31 | jeffhardingabb | Fixed in Version | => 1.04 |
| 2016-12-16 17:31 | jeffhardingabb | Resolution | open => fixed |
| 2017-01-12 17:04 | Jim Luth | Note Added: 0007731 | |
| 2017-01-12 17:04 | Jim Luth | Status | resolved => closed |
