alamb opened a new pull request, #27238: URL: https://github.com/apache/datafusion/pull/27238
## Which issue does this PR close? - N/A, documentation only. ## Rationale for this change While reviewing https://github.com/apache/datafusion/pull/27191 I was researching how `EquivalenceProperties` tracks orderings, equal expressions and constants, and wanted to write down what I learned so others do not have to repeat it. Several of the struct docs in the `equivalence` module were out of date or hard to follow. For example, the `ConstExpr` docs still described `across_partitions` as a boolean flag. ## What changes are included in this PR? Rustdoc only, in `datafusion/physical-expr/src/equivalence/`: - `mod.rs`: a module doc that says what the module holds and points at `EquivalenceProperties` as the place to start. - `class.rs`: `AcrossPartitions` documents its variants on the variants; `ConstExpr` drops the stale "boolean flag" field description; `EquivalenceClass` and `EquivalenceGroup` get shorter summaries. Each links to the relevant section of the `EquivalenceProperties` docs. - `ordering.rs`: `OrderingEquivalenceClass` moves the no-suffix-is-a-prefix invariant onto the `orderings` field, links to `GroupingEquivalenceClass` as its counterpart for contiguous-but-unsorted groups, and `is_expr_partial_const` says what the encoding is for and links to the section that explains it. The `EquivalenceProperties` sections these link to (`#constants`, `#equivalent-expressions`, `#equivalent-sort-expressions`, `#per-partition-constants-from-window-functions`) are added in https://github.com/apache/datafusion/pull/27234, of which this PR is a split. Until that merges the links land on the struct page without a matching heading. The "Future Improvements" note removed from `is_expr_partial_const` moves into that section in the same PR. Companion split: https://github.com/apache/datafusion/pull/27237 (the `GroupingEquivalenceClass` side of the cross-link). ## What is the testing strategy for this PR? No code changes. `cargo doc` with `-D warnings` passes, so the intra-doc links resolve. ## Are there any user-facing changes? No. -- 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]
