chore: Fix duplicated word typos in comments and docs

[geographybuff]

Which issue does this PR close?

N/A — small standalone cleanup, following the precedent of recent comment-typo PRs merged without a linked issue:

• chore: Fix typos #10956 chore: Fix typos (47 files, +108/-107)
• chore: fix typos in code comments #10943 chore: fix typos in code comments (11 files, +16/-16)
• chore: fix typo in release email template #10530 chore: fix typo in release email template

Rationale for this change

Several comments contain accidentally doubled words — run-encoded encoded data, and and an offset, typed typed on, are used used. Most are rustdoc on public items, so they render on docs.rs.

These survive automated checking because the CI spell check (.github/ci/scripts/typos_check.sh, the typos crate) matches misspelled words and does not detect a correctly spelled word repeated twice in a row. typos --config typos.toml passes on both the unmodified tree and this branch.

One case is more than cosmetic. In parquet/src/file/metadata/thrift/mod.rs, the PageHeader doc comment is a transcription of the Parquet Thrift IDL, and reads to be be calculated as follows. Upstream parquet-format's parquet.thrift reads to be calculated, so this is a transcription slip and the fix restores agreement with the spec.

Found by searching the tree for \b(\w+)\s+\1\b restricted to comment and prose lines. The remaining matches are ASCII-art layout diagrams in list_array.rs / list_view_array.rs (Logical Logical column headings) and correct English like 100-row row group; those are left alone.

What changes are included in this PR?

Removes 13 doubled words across 11 Rust files and 1 Markdown file. Comment and prose text only — no code changes.

File	Fix
arrow-buffer/src/lib.rs	Run-ends used in run-encoded encoded data
arrow-buffer/src/util/bit_chunk_iterator.rs	and and an offset and length in bits
arrow-array/src/array/run_array.rs	A RunArray typed typed on its child values array
arrow-data/src/data.rs	2. the the null count is correct
arrow-data/src/transform/mod.rs	Note this this is not stored in _MutableArrayData
parquet/src/file/properties.rs	default values for ndv and fpp value are used used
parquet/src/file/metadata/mod.rs (x2)	Takes ownership of the the column metadata; Returns a reference to the the histogram's values
parquet/src/file/metadata/thrift/mod.rs	CRC checksum for the page, to be be calculated
parquet/src/arrow/mod.rs	the AES encryption keys required required for decrypting
parquet/src/arrow/arrow_reader/mod.rs	maximum size of value to pass to to value generator
parquet/src/arrow/arrow_reader/statistics.rs	extracting i128 values from from an iterator
parquet_derive/README.md	You must must enable the chrono feature

Are these changes tested?

No new tests — the change is confined to comments and prose, so there is no behaviour to cover.

Checks run locally on Linux x86_64 with the pinned 1.98.1 toolchain:

• typos --config typos.toml (v1.37.0, the version pinned in dev.yml) — pass

• cargo fmt --all --check — pass

• cargo test --doc -p arrow-buffer -p arrow-array -p arrow-data -p parquet --all-features — pass, 376 doctests, 0 failed (arrow-array 206, parquet 96, arrow-buffer 60, arrow-data 14)

  This first failed with 5 errors, all of them PARQUET_TEST_DATA is undefined from an uninitialised parquet-testing submodule rather than anything in this PR. The numbers above are from the re-run after git submodule update --init.

parquet_derive/README.md is outside the prettier glob in dev.yml ({arrow,arrow-flight,dev,arrow-integration-testing,parquet}/**/*.md), so the docs formatting job is unaffected.

I did not run the full test suite. One edited line sits inside a rustdoc example (parquet/src/arrow/mod.rs, the encryption example), and that doctest is covered by the run above; every other edited line is an ordinary comment.

Are there any user-facing changes?

No API or behaviour changes. The rendered rustdoc is corrected for RunEndBuffer, UnalignedBitChunk::new, Int64RunArray, ArrayData, WriterProperties, ColumnChunkMetaDataBuilder::take_column_metadata, Histogram::values, PageHeader, and two parquet::arrow reader items.

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AI disclosure

This contribution was AI-assisted. Claude Code (Claude Opus 5) performed the tree-wide doubled-word search, made the 13 line edits, checked the PageHeader comment against upstream parquet-format, and ran every check listed above. The check commands were executed by the AI and have not been independently re-run by hand.

[Jefffrey]

do we need such a verbose PR body for these simple fixes 😅

[Rich-T-kid]

thanks!