From e238f40605a47739c63751a7c31038f9835406cb Mon Sep 17 00:00:00 2001 From: jedarden Date: Wed, 27 May 2026 22:54:08 -0400 Subject: [PATCH] docs(pdftract-14w0w): verify gap detection implementation complete The detect_column_gaps function was already implemented in columns.rs with full test coverage. All acceptance criteria verified: - 8 zeros < threshold: no gap - 20 zeros middle: 1 gap detected - Leading zeros >= threshold: gap emitted - All-zero histogram: 0 gaps Co-Authored-By: Claude Opus 4.7 --- notes/pdftract-14w0w.md | 44 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 notes/pdftract-14w0w.md diff --git a/notes/pdftract-14w0w.md b/notes/pdftract-14w0w.md new file mode 100644 index 0000000..5d81b11 --- /dev/null +++ b/notes/pdftract-14w0w.md @@ -0,0 +1,44 @@ +# pdftract-14w0w: Gap detection verification + +## Summary + +The `detect_column_gaps` function was already implemented in `crates/pdftract-core/src/layout/columns.rs` (lines 156-201). All acceptance criteria tests pass. + +## Implementation details + +The function: +- Takes histogram slice and page_width +- Calculates threshold: `(page_width * 0.03).ceil() as usize` +- Returns `Vec` + +Key behaviors: +- Handles leading zeros (left margin) - emits gap if >= threshold +- Handles trailing zeros (right margin) - emits gap if >= threshold +- Handles all-zero histogram (empty page) - returns no gaps +- Handles empty histogram - returns no gaps + +## Acceptance criteria verification + +| Criterion | Test | Status | +|-----------|------|--------| +| 8 zeros, page_width=600: NO gap | `test_detect_column_gaps_short_zeros_no_gap` | PASS | +| 20 zeros middle, page_width=600: 1 gap | `test_detect_column_gaps_middle_gap` | PASS | +| Leading zeros >= threshold: 1 gap | `test_detect_column_gaps_leading_gap` | PASS | +| All-zero histogram: 0 gaps | `test_detect_column_gaps_all_zeros_no_gaps` | PASS | + +Additional tests: +- `test_detect_column_gaps_trailing_gap` - trailing margin gap +- `test_detect_column_gaps_multiple_gaps` - multiple separated gaps +- `test_detect_column_gaps_threshold_exact` - gap at exact threshold +- `test_detect_column_gaps_threshold_minus_one` - gap just below threshold +- `test_detect_column_gaps_empty_histogram` - empty input +- `test_detect_column_gaps_no_zeros` - no gaps in histogram +- `test_detect_column_gaps_small_page` - small page width +- `test_detect_column_gaps_leading_and_trailing` - both margins + +All 36 column tests PASS (including 13 detect_column_gaps tests). + +## Files verified + +- `crates/pdftract-core/src/layout/columns.rs` - implementation (lines 89-201) +- `crates/pdftract-core/src/layout/mod.rs` - exports ColumnGap, detect_column_gaps