LorenzoMartini opened a new pull request, #39367:
URL: https://github.com/apache/spark/pull/39367
<!--
Thanks for sending a pull request! Here are some tips for you:
1. If this is your first time, please read our contributor guidelines:
https://spark.apache.org/contributing.html
2. Ensure you have added or run the appropriate tests for your PR:
https://spark.apache.org/developer-tools.html
3. If the PR is unfinished, add '[WIP]' in your PR title, e.g.,
'[WIP][SPARK-XXXX] Your PR title ...'.
4. Be sure to keep the PR description updated to reflect all changes.
5. Please write your PR title to summarize what this PR proposes.
6. If possible, provide a concise example to reproduce the issue for a
faster review.
7. If you want to add a new configuration, please read the guideline first
for naming configurations in
'core/src/main/scala/org/apache/spark/internal/config/ConfigEntry.scala'.
8. If you want to add or modify an error type or message, please read the
guideline first in
'core/src/main/resources/error/README.md'.
-->
### What changes were proposed in this pull request?
The `ScanBuilder` interface has the `build()` method to return `Scan`
objects. All the different implementations of it return scans that are of the
type of the builder itself. Eg `ParquetScanBuilder` will return a
`ParquetScan`, `TextScanBuilder` a `TextScan` etc. However, in the method
overrides declaration, the return type is not changed to the more specific type
but left as a generic `Scan`. For ease of development I'm proposing that the
the `build()` methods of each implementation of `ScanBuilder`s returned a more
strictly typed object instead of the generic `Scan` object
### Why are the changes needed?
When developing using spark as a library, it can be problematic to deal with
the scan types as often manual casting is required when we should know for a
fact that typed `ScanBuilder`s return typed scans. In order to avoid having to
hard cast objects and have stricter requirements on the return types (We want a
`ParquetScanBuilder` to return `ParquetScan`s only) these changes would be
really helpful.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
No need to test as we are just changing the declared return type to the
effective return type of the scanbuilders.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
