18af6bb01d
Blocker identified: - Extraction pipeline (extract.rs) doesn't use Phase 4 layout pipeline - Column detection functions never called in production - SpanJson.column hardcoded to None (lines 1059, 1916) - No end-to-end tests for acceptance criteria Span struct HAS column field (line 179) but extraction doesn't use it. Coordinator CANNOT CLOSE - sub-phase not end-to-end functional.
90 lines
3.8 KiB
Markdown
90 lines
3.8 KiB
Markdown
# Verification Note: pdftract-63ka2 (Updated 2026-05-28)
|
|
|
|
## Bead
|
|
Phase 4.3: Column Detection (coordinator)
|
|
|
|
## Current Status: BLOCKER - DO NOT CLOSE
|
|
|
|
### Children Status
|
|
All 4 children are CLOSED:
|
|
- `pdftract-56vwd` - x0 histogram builder - CLOSED ✓
|
|
- `pdftract-14w0w` - Gap detection - CLOSED ✓
|
|
- `pdftract-2rkc1` - Column confirmation - CLOSED ✓
|
|
- `pdftract-64j83` - Column label assignment - CLOSED ✓
|
|
|
|
### Implementation Status
|
|
Column detection functions are fully implemented in `crates/pdftract-core/src/layout/columns.rs`:
|
|
- `build_x0_histogram()` - 49 unit tests pass
|
|
- `detect_column_gaps()` - Part of the 49 tests
|
|
- `confirm_columns()` - Part of the 49 tests
|
|
- `assign_columns_to_spans()` - Part of the 49 tests
|
|
- `assign_columns_to_lines()` - Part of the 49 tests
|
|
|
|
### Integration Status: BLOCKER (As of 2026-05-28)
|
|
|
|
Column detection is NOT integrated into the main extraction pipeline:
|
|
|
|
1. **Main `Span` struct HAS column field but it's never used**
|
|
- File: `crates/pdftract-core/src/span/mod.rs:179`
|
|
- The `Span` struct DOES have `column: Option<u32>` field (updated since initial note)
|
|
- However, the extraction pipeline never assigns column values
|
|
|
|
2. **Extraction pipeline does not call column detection**
|
|
- File: `crates/pdftract-core/src/extract.rs`
|
|
- Column detection functions are never invoked (grep found no matches)
|
|
- `SpanJson::column` is hardcoded to `None` (lines 1059, 1916)
|
|
- The extraction pipeline doesn't use `cluster_spans_into_lines` or column detection at all
|
|
|
|
3. **No end-to-end tests for column detection**
|
|
- No fixture tests for three-column papers
|
|
- No fixture tests for full-width headings above two-column body
|
|
- No fixture tests for single-column pages
|
|
|
|
### Acceptance Criteria
|
|
|
|
- [PASS] All 4 children closed
|
|
- [FAIL] Three-column academic paper: three distinct columns detected - NOT VERIFIED
|
|
- [FAIL] Full-width heading above two-column body: heading spans not assigned a column - NOT VERIFIED
|
|
- [FAIL] Single-column page: no false column splits - NOT VERIFIED
|
|
|
|
## Blockers
|
|
|
|
The extraction pipeline (`extract.rs`) needs to be refactored to use the Phase 4 layout pipeline:
|
|
|
|
1. **Add Phase 4 pipeline integration**
|
|
- File: `crates/pdftract-core/src/extract.rs`
|
|
- Currently the pipeline doesn't use line formation or column detection
|
|
- Need to add: glyph → span → line → column detection → block formation
|
|
- Current pipeline goes directly from glyphs to spans to blocks without line/column phases
|
|
|
|
2. **Implement column detection call chain**
|
|
- After line formation (Phase 4.2), call:
|
|
- `build_x0_histogram(spans, page_width)`
|
|
- `detect_column_gaps(&hist, page_width)`
|
|
- `confirm_columns(&gaps, page_width, &lines)`
|
|
- `assign_columns_to_spans(spans, &columns)`
|
|
- `assign_columns_to_lines(lines)`
|
|
- Pass the column value to `SpanJson` constructor
|
|
|
|
3. **Add end-to-end tests**
|
|
- Create fixture for three-column academic paper
|
|
- Create fixture for two-column page with full-width heading
|
|
- Create fixture for single-column page
|
|
- Verify column detection produces correct labels
|
|
|
|
## Recommendation
|
|
|
|
**DO NOT CLOSE this coordinator bead.** The sub-phase implementation is incomplete because:
|
|
1. The extraction pipeline doesn't use the Phase 4 layout pipeline
|
|
2. Column detection functions are never called in production
|
|
3. No end-to-end verification of acceptance criteria
|
|
|
|
The child beads being closed only means the individual functions are implemented and unit-tested. The coordinator must ensure the sub-phase works end-to-end, which requires integration into the extraction pipeline.
|
|
|
|
## Next Steps
|
|
|
|
This coordinator bead requires significant extraction pipeline refactoring:
|
|
1. Integrate Phase 4.2 line formation into extract.rs
|
|
2. Add Phase 4.3 column detection after line formation
|
|
3. Update SpanJson to use computed column values
|
|
4. Add fixture tests for acceptance criteria verification
|