pdftract/notes/pdftract-4brcu.md

pdftract-4brcu: List Detection Implementation

Summary

The list detection implementation was already complete in crates/pdftract-core/src/layout/list.rs. This task verified that the implementation meets all acceptance criteria.

Implementation Details

Location

• File: crates/pdftract-core/src/layout/list.rs
• Module: pdftract_core::layout::list
• Exported via: crates/pdftract-core/src/layout/mod.rs

Key Functions

1. classify_list<S, L>(block: &Block<S>) -> bool

   • Returns true when ≥80% of block's lines start with bullet/numbered pattern
   • Empty blocks return false

2. starts_with_bullet(line_text: &str) -> bool

   • Pattern: ^\s*[•‣◦⁃\-\*]\s
   • Matches Unicode bullets and ASCII marks

3. starts_with_number(line_text: &str) -> bool

   • Pattern: ^\s*\d+[.\)]\s
   • Matches "1.", "2)", etc.

Regex Patterns

BULLET_RE:    r"^\s*[•‣◦⁃\-\*]\s"
NUMBER_RE:    r"^\s*\d+[.\)]\s"

Acceptance Criteria Verification

All acceptance criteria PASS:

#	Criterion	Test	Result
1	3 "* Item" lines → List	test_classify_list_three_bullet_items	PASS
2	3 "1. First/2. Second/3. Third" lines → List	test_classify_list_three_numbered_items	PASS
3	1 "* Solo" line → List	test_classify_list_single_bullet_item	PASS
4	4/5 "- " starts → List	test_classify_list_four_of_five_bullet_items	PASS
5	2/5 "- " starts → NOT List	test_classify_list_two_of_five_bullet_items	PASS

Test Results

running 20 tests
test layout::list::tests::test_classify_list_empty_block ... ok
test layout::list::tests::test_classify_list_exactly_80_percent ... ok
test layout::list::tests::test_classify_list_four_of_five_bullet_items ... ok
test layout::list::tests::test_classify_list_just_below_80_percent ... ok
test layout::list::tests::test_classify_list_mixed_bullet_and_numbered ... ok
test layout::list::tests::test_classify_list_single_bullet_item ... ok
test layout::list::tests::test_classify_list_three_bullet_items ... ok
test layout::list::tests::test_classify_list_three_numbered_items ... ok
test layout::list::tests::test_classify_list_two_of_five_bullet_items ... ok
test layout::list::tests::test_classify_list_unicode_bullets ... ok
test layout::list::tests::test_classify_list_zero_matching ... ok
... (9 more helper tests for starts_with_bullet/starts_with_number)

test result: ok. 20 passed; 0 failed

Notes

• Lettered (a., b.) and Roman (I., II.) lists are NOT covered in v0.1.0 (as per plan)
• Indented sub-bullets (nesting) is deferred (as per plan)
• Unicode bullets (•, ‣, ◦, ⁃) are matched as literal codepoints (per INV)

Git Status

No file changes required - implementation was already complete and passing.