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Author SHA1 Message Date
Abimael Martell b67b45cedc fix(tables): stop dropping body-band scripts from the candidate set
Valid: the body-font pass filtered scripts out of body_candidates
itself, so body_script_flags and its two downstream uses were dead. The
mask filters region_evidence and feeds detect_table_in_region's is_script
closure, but neither ever saw a script item because the candidate set no
longer contained any.

Consequences: a body-band sub/superscript attached to a heading-sized
anchor was dropped from the table outright rather than assigned to a
cell, so its text was lost — the opposite of what both the
body_script_flags comment ('they stay candidates') and the
detect_table_in_region docstring ('they remain eligible for cell
assignment') describe, and inconsistent with the small-font pass.

Root cause: the geometry rework removed the candidate-level filter from
the small-font pass, but the body one had been reflowed onto a single
line by rustfmt so the same edit missed it. Adding body_script_flags in
a later review then wired a mask that the surviving filter made
unreachable.

No measured change on either benchmark — pdf-evals still 20 documents
and -367 table rows, opendataloader still overall +0.0003 / mhs +0.0003
with one document changed — because the combination it affects (a
body-sized script attached to a heading-sized anchor) does not occur in
either corpus. The fix is for correctness and consistency between the
two passes, not for a score.

964 tests pass, clippy clean.
2026-08-06 16:24:14 -07:00
Abimael Martell efd875a944 test: cover the roman length bound with a nine-character token
Valid P3. The 'MMMM.' case fails on the unsupported M, not on length, so
the 8-character bound in roman_value had no coverage and could regress
silently. Added a nine-'I' token, which is rejected only by the bound,
plus an eight-'I' token that must stay exempt to pin the boundary from
both sides.
2026-08-06 13:34:09 -07:00
Abimael Martell f68cc39972 review: share roman_value so the veto exemption matches the parser
Valid. My numbering predicate accepted tokens heading::parse_numbering
rejects — lowercase 'iv)', alphabetical 'd)', over-long 'MMMM.' — because
it case-folded and allowed D and M. Anything the parser rejects is not
numbering, so exempting it let ordinary list items bypass the
dangling-verb veto and reach font-based heading promotion.

Rather than restate the grammar, roman_value is now pub(super) and the
exemption calls it, so the two cannot drift. Its rules apply as written:
uppercase I/V/X/L/C only, at most 8 characters, positive total.

Decimal numbering keeps its slightly broader acceptance (bare '2.3' with
no trailing delimiter), which is deliberate and documented — that form is
common in real headings and being permissive in a veto exemption cannot
manufacture a heading, only decline to suppress one. The roman case is
different because single letters collide with alphabetical list markers.

No measured change: opendataloader overall +0.0003 / mhs +0.0003, doc
01030000000144 still 0.732 -> 0.785. 964 tests pass, clippy clean.
2026-08-06 13:18:38 -07:00
Abimael Martell dafcff5ea3 review: exempt section-numbered lines from the dangling-verb veto
Valid ordering bug. heading.rs consults is_heading_fragment at line 282
and only applies its numbered-prefix allowance at line 288, so the veto
pre-empted it: '1. What the model implies' is sentence case and ends on
a listed verb, so it was discarded before numbering could vouch for it.

Numbering is independent evidence of a heading, so the veto now skips
any line opening with a section number.

Acceptance is deliberately a little broader than heading::parse_numbering
(which requires a trailing delimiter) because '2.3 Section Title' is
written without one, and being permissive in a veto exemption can only
avoid suppressing headings. Two guards keep it from swallowing prose:

- a bare single number needs a delimiter ('1.' yes, '3 apples' no)
- roman numerals always need one, since a leading 'I' is the pronoun far
  more often than a section number

Not reused from convert::starts_with_section_number, which deliberately
demands two components because it bypasses isolation checks — that would
reject the reviewer's single-'1.' case.

No measured change: opendataloader still overall +0.0003 / mhs +0.0003
with doc 01030000000144 at 0.732 -> 0.785, pdf-evals still 20 documents,
target case still suppressed. 964 tests pass, clippy clean.
2026-08-06 13:04:21 -07:00
Abimael Martell d883b44e1d review: gate the dangling-verb veto on sentence case, drop 'yields'
Cubic review of a5a6e8f — both findings valid.

1. 'yields' is also a plural noun. 'Bond Yields', 'Crop Yields' and
   'Dividend Yields' are real section titles in financial documents,
   which this corpus contains. Removed from the list; my claim that
   these verbs 'never end a heading in any register' was wrong for it.

2. A wrapped title-case heading whose first line ends on one of these
   verbs would be suppressed if the heading preprocessor failed to
   merge it.

Both are fixed by the same gate, which is the discriminator I was
missing: case. A heading is title case ('Bond Yields', 'The Theorem
Implies'); a stranded lead-in is sentence case ('Note that the exact
error equals', 'the method yields'). The veto now applies only when
every content word is NOT capitalized, so titles are spared regardless
of their final word.

This is also why the earlier function-word and copula variants failed:
they had no way to tell 'Rule 15. Your AGI Must Be' from 'the tax
burden should be'. Case separates those two as well.

No measured cost. opendataloader is unchanged from the previous
revision — overall +0.0003, mhs +0.0003, doc 01030000000144 still
0.732 -> 0.785 — and pdf-evals still 20 documents. 963 tests pass,
clippy clean.
2026-08-06 12:41:09 -07:00
Abimael Martell a5a6e8fbea fix(markdown): reject headings that end on a relational verb
A heading candidate ending in 'equals', 'denotes', 'implies' and the
like is the first half of a sentence, not a title. This shows up when a
block dissolves and strands its lead-in ahead of the formula it
introduced — opendataloader 01030000000144 produced

    ## Note that the exact error equals
    M - Q(h) = e - 2.7525... = -0.0342....

Deliberately a very short list. Broader variants were tried and
measured, then rejected:

- Function words (of/and/for/the): a heading that WRAPS across lines
  ends on exactly those. Destroyed real IRS Publication 17 headings —
  'Casualty and' -> 'Casualty and Theft Losses', 'Rule 10. You Must Be
  at' -> '... At Least Age 25'. 52 documents affected, -619 headings.
- Copulas and auxiliaries (is/are/be/have): same failure. 'Rule 15.
  Your AGI Must Be', 'What Medical Expenses Are' and 'When Can a Roth
  IRA Be' are real wrapped headings, while 'the tax burden should be'
  is a genuine fragment. The trailing word cannot separate them; that
  needs the next line's context, which this text-only predicate lacks.

The verbs kept never end a heading in any register, so they are safe
without context. Standalone the guard is a no-op on both benchmarks
(0 documents on opendataloader, 4 on pdf-evals with no net heading
change) — its value is as a companion to the table filter in this PR,
which is what strands these lead-ins.

Combined effect on opendataloader (200 docs, vs a control build of
main), where the table filter alone regressed:

                 table filter    + this guard
    overall        -0.0003          +0.0003
    mhs            -0.0019          +0.0003
    doc ...144     -0.063           +0.053
    doc ...144 mhs -0.203           +0.028
2026-08-06 12:20:53 -07:00
Abimael Martell 85a5150062 fix(tables): use a heading-anchored script mask in the body-font pass
Cubic review of #264: a single script mask computed with a 0.0 anchor
was applied to both passes, including body-font region qualification and
geometry. The body pass is supposed to require a heading-sized anchor —
that distinction existed before the geometry rework and was lost in it.

Why it matters: body-pass candidates are themselves body-sized
(0.85..1.05x base). A cell at the low end of that band, say 8.5pt,
sitting beside a 10.5pt label clears the inherent 'anchor >= 1.2x cell'
rule (10.2) and so was flagged as a script attachment. At body sizes a
slightly larger neighbour is a bold label or column header, not the base
of a superscript, so flagging it stripped real cells out of the region
evidence and column geometry and could lose the table entirely.

Two masks now: the small-font pass keeps the 0.0 anchor, the body pass
requires >= 1.15x base. Note the threshold only bites below base size —
for a cell at base, 1.2x-of-cell already exceeds 1.15x-of-base — which
is exactly the 0.85..1.0x band cubic identified.

Corpus: 20 documents, net -367 table rows (was -359 with the single
mask), so the body pass now keeps 8 rows of real table it had been
discarding. 958 tests pass, clippy clean.
2026-08-04 20:27:09 -07:00
Abimael Martell beba62d8e5 fix(tables): suppress script column evidence instead of dropping candidates
Reworked after reviewing the corpus diffs: the first approach removed
sub/superscripts from table candidates entirely, which had two failure
modes beyond the intended fix.

- Legitimate cell content was displaced. citizen-sr-282 is a calculator
  manual whose engineering-notation table lists M = 10^6, k = 10^3.
  Those exponents are superscripts, so they were dropped from the table
  and resurfaced elsewhere in the reading order ('9 mega 6 kilo = 10 3
  milli').
- Removing items changed the candidate geometry, so different spurious
  structure could form from what remained.

Scripts are now kept as candidates and excluded only from the geometry:
they cannot create a column (find_column_boundaries), cannot qualify a
region on their own (find_table_regions / _strict), but are still
assigned to cells. Column alignment is validated against ALL items
including scripts — validating only the non-script subset would let a
region manufacture alignment by ignoring its awkward items, which is
what block-diagram pages did.

Corpus: 20 of 186 documents, net -359 table rows, no content lost.
Token-level comparison shows the only text changes are merges in the
right direction: 'X' + '10' becomes 'X10', 'L' + 'g' becomes 'Lg' —
subscripts joining their base instead of floating free.

Remaining artifact: MCF5235RM (and its _nxp duplicate) gains a small
spurious table from a block-diagram label line, and M2019_mordeste
gains 11 rows from a 3-column grid re-detected as 2-column. Both are
borderline regions where the previous output was also wrong; documented
rather than tuned away.

805 unit + 148 integration tests pass, clippy clean.
2026-08-04 18:46:30 -07:00
Abimael Martell dbd56681b5 fix(tables): exclude script attachments and tiny numeric fragments from detection
Split out of #242 (draft) so it can be reviewed on its own evidence.

Display equations with sub/superscripts form phantom small-font table
regions: the subscripts cluster with nearby small text (footnotes, axis
labels) into fake multi-column grids. Two guards:

- Script attachment: a small-font item horizontally adjacent to a
  larger-font item at a genuine baseline offset is a sub/superscript,
  not a table cell, and is excluded from candidates. A real baseline
  offset is required so a small cell beside a larger same-baseline
  label is never filtered. Attachment targets are indexed by Y and
  scanned through a bounded window rather than a full-page sweep.
  The body-font pass applies the same exclusion but only for
  heading-sized anchors (>= 1.15x base), so body-size table cells
  beside slightly larger labels are untouched.
- Tiny numeric fragments: a <=2-row grid whose every cell is a bare
  1-2 digit number carries no tabular information. Restricted to the
  small-font pass, where the pattern is overwhelmingly exponent
  clusters; body-font numeric grids are unaffected.

Corpus impact: 20 of 186 documents, measured against a control build of
main so main's own drift is excluded. Table rows fall in 17 of 18
inspected documents and no content is lost — 2103_07786 drops all 21
rows, every one a math fragment ('|X 42 43|1|||'); Stijn_SB_doc drops
173 rows of footnote text that had been shredded into cells, with word
count slightly UP and footnote markers intact. M2019_mordeste gains 11
rows from a 3-column grid re-detected as 2-column, neither clearly
better nor worse.

Note the 20 documents is far more than the 3 that per-change ablation
suggested: that figure measured sole-cause attribution inside the
original combined PR, where other heuristics changed the same files and
masked this one. Reach and sole-cause are different measurements.

805 unit + 148 integration tests pass, clippy clean, in-repo snapshots
unchanged.
2026-08-04 18:07:34 -07:00
3 changed files with 503 additions and 11 deletions
+192
View File
@@ -171,6 +171,74 @@ pub(crate) fn is_toc_marker_heading(text: &str) -> bool {
/// equation and absent from name-plus-number headings. A bare trailing colon
/// is NOT a fragment signal either: real headings frequently end with colons
/// ("Procedure:", "Steps for Using the Microscope:").
/// True when the line opens with a section number ("3.", "2.1.4", "IV)").
///
/// Mirrors the acceptance of `heading::parse_numbering` rather than the
/// stricter `convert::starts_with_section_number`, which deliberately
/// requires two components because it bypasses isolation checks. Here a
/// single "1." counts: numbering is independent evidence of a heading, and
/// `heading.rs` applies its numbered-prefix allowance *after* consulting
/// `is_heading_fragment`, so without this exemption a numbered
/// sentence-case heading would be vetoed before that allowance can run.
fn starts_with_numbering_prefix(t: &str) -> bool {
let Some(first) = t.split_whitespace().next() else {
return false;
};
let has_delimiter = first.ends_with(['.', ')', ':']);
let token = first.trim_end_matches(['.', ')', ':']);
if token.is_empty() {
return false;
}
let parts: Vec<&str> = token.split('.').collect();
let decimal = parts
.iter()
.all(|p| !p.is_empty() && p.len() <= 3 && p.chars().all(|c| c.is_ascii_digit()));
if decimal {
// "1." / "2.1." carry a delimiter; "2.3 Title" is written without
// one, so a multi-component number is accepted bare. A bare single
// number ("3 apples") is not — that is ordinary prose.
return has_delimiter || parts.len() >= 2;
}
// Roman numerals go through the heading parser's own grammar so the two
// agree: uppercase I/V/X/L/C only, at most 8 characters. A looser rule
// here would exempt markers the parser rejects — "iv)" or "d)" from an
// alphabetical list — letting an ordinary list item bypass the veto and
// reach heading promotion.
//
// A delimiter is also required: a bare leading "I" is the pronoun far
// more often than a section number.
has_delimiter && crate::markdown::heading::roman_value(token).is_some()
}
/// True when the line reads as a title rather than a sentence: every
/// content word (ignoring minor words) starts uppercase. Used to spare real
/// headings from the dangling-verb veto — "Bond Yields" is a section title,
/// "the method yields" is a stranded clause, and only the casing tells them
/// apart.
fn looks_title_case(t: &str) -> bool {
const MINOR: &[&str] = &[
"a", "an", "the", "of", "and", "or", "for", "to", "in", "on", "at", "by", "with", "from",
"as", "is", "are", "that", "than", "into",
];
let mut content = 0usize;
let mut capitalized = 0usize;
for w in t.split_whitespace() {
let cleaned: String = w.chars().filter(|c| c.is_alphabetic()).collect();
if cleaned.is_empty() {
continue;
}
if MINOR.contains(&cleaned.to_lowercase().as_str()) {
continue;
}
content += 1;
if cleaned.chars().next().is_some_and(char::is_uppercase) {
capitalized += 1;
}
}
// A single content word ("Yields") is a title by default.
content == 0 || capitalized == content
}
pub(crate) fn is_heading_fragment(text: &str) -> bool {
let t = text.trim_end();
@@ -244,9 +312,133 @@ pub(crate) fn is_heading_fragment(text: &str) -> bool {
if t.ends_with(':') && t.split_whitespace().any(is_equation_number) {
return true;
}
// Dangling clause: a stranded sentence lead-in ends on a relational
// verb with no terminal punctuation — "Note that the exact error equals"
// left ahead of its formula when a phantom table dissolved.
//
// Gated on the line reading as prose rather than a title. Case is the
// discriminator the trailing word alone cannot provide: a heading is
// title case ("Bond Yields", "The Method Yields") while a stranded
// lead-in is sentence case ("the method yields"). Without this gate the
// veto eats real headings — "Bond Yields", "Crop Yields" and any wrapped
// title-case heading the preprocessor failed to merge.
if !t.ends_with(['.', '!', '?', ':', ';', ')', ']'])
&& !looks_title_case(t)
&& !starts_with_numbering_prefix(t)
{
if let Some(last) = t.split_whitespace().next_back() {
let word: String = last
.trim_matches(|c: char| !c.is_alphanumeric())
.to_lowercase();
// Relational verbs only, and only those with no common noun
// sense. "yields" was dropped for exactly that reason: "Bond
// Yields" is a real section title. Function words, copulas and
// auxiliaries were measured and rejected outright — a heading
// that wraps across lines ends on those, and suppressing them
// destroyed real IRS Publication 17 headings.
const DANGLING_TAIL: &[&str] =
&["equals", "denotes", "implies", "satisfies", "signifies"];
if DANGLING_TAIL.contains(&word.as_str()) {
return true;
}
}
}
false
}
#[cfg(test)]
mod fragment_heading_tests {
use super::is_heading_fragment;
#[test]
fn dangling_tail_marks_stranded_clause() {
// opendataloader 01030000000144: left behind when a phantom table
// dissolved, ahead of its formula on the next line.
assert!(is_heading_fragment("Note that the exact error equals"));
assert!(is_heading_fragment("The remainder term satisfies"));
assert!(is_heading_fragment("we conclude that the sum equals"));
}
#[test]
fn real_headings_survive() {
assert!(!is_heading_fragment("Introduction"));
assert!(!is_heading_fragment("Error Analysis"));
assert!(!is_heading_fragment("Materials and Methods"));
assert!(!is_heading_fragment("Results"));
assert!(!is_heading_fragment("3.2 Richardson Extrapolation"));
assert!(!is_heading_fragment("Discussion and Conclusions"));
// Terminal punctuation means the clause is complete.
assert!(!is_heading_fragment("What is a Derivative?"));
assert!(!is_heading_fragment("Procedure:"));
assert!(!is_heading_fragment("Note that this is important."));
}
#[test]
fn title_case_headings_ending_in_a_verb_survive() {
// "yields" is also a plural noun; these are real section titles.
assert!(!is_heading_fragment("Bond Yields"));
assert!(!is_heading_fragment("Crop Yields"));
assert!(!is_heading_fragment("Dividend Yields"));
assert!(!is_heading_fragment("Yields"));
// A wrapped title-case heading whose first line ends on a listed
// verb must survive even if the preprocessor failed to merge it.
assert!(!is_heading_fragment("The Theorem Implies"));
assert!(!is_heading_fragment("What This Denotes"));
}
#[test]
fn numbered_sentence_case_headings_survive() {
// heading.rs consults is_heading_fragment BEFORE applying its
// numbered-prefix allowance, so the veto must not pre-empt it.
assert!(!is_heading_fragment("1. What the model implies"));
assert!(!is_heading_fragment("2.3 How the estimator satisfies"));
assert!(!is_heading_fragment("IV) What this denotes"));
// Without numbering the same wording is still a stranded clause.
assert!(is_heading_fragment("What the model implies"));
// A bare leading number or pronoun is prose, not numbering.
assert!(is_heading_fragment("3 apples and what that implies"));
assert!(is_heading_fragment("I think the model implies"));
// Markers heading::parse_numbering rejects must not be exempted
// either, or an ordinary list item bypasses the veto: lowercase
// roman, alphabetical markers, and over-long tokens.
assert!(is_heading_fragment("iv) the estimator satisfies"));
assert!(is_heading_fragment("d) the value implies"));
// Unsupported character (M is outside the parser's I/V/X/L/C set).
assert!(is_heading_fragment("MMMM. the value implies"));
// Over-long token: nine valid characters, so this exercises the
// 8-character bound rather than the character set.
assert!(is_heading_fragment("IIIIIIIII. the value implies"));
// Eight is still within the bound and stays exempt.
assert!(!is_heading_fragment("IIIIIIII. What this implies"));
// Uppercase roman within the parser's grammar is still exempt.
assert!(!is_heading_fragment("IV. What this denotes"));
assert!(!is_heading_fragment("XII) What this implies"));
}
#[test]
fn wrapped_headings_are_not_fragments() {
// A heading that wraps across lines ends on a function word. These
// are real headings from IRS Publication 17 and must survive.
assert!(!is_heading_fragment("Casualty and"));
assert!(!is_heading_fragment("Rule 10. You Must Be at"));
assert!(!is_heading_fragment("Higher Standard Deduction for"));
assert!(!is_heading_fragment("Qualifying Child of"));
assert!(!is_heading_fragment("When Can I Withdraw or"));
// Copulas and auxiliaries also end real wrapped headings.
assert!(!is_heading_fragment("Rule 15. Your AGI Must Be"));
assert!(!is_heading_fragment("What Medical Expenses Are"));
assert!(!is_heading_fragment("Rule 13. You Must Have"));
assert!(!is_heading_fragment("When Can a Roth IRA Be"));
}
#[test]
fn dangling_check_is_case_insensitive() {
// All-caps is not sentence case, so the veto must not fire there.
assert!(!is_heading_fragment("THE REMAINDER EQUALS"));
}
}
/// Compute the Y-gap threshold for paragraph break detection.
///
/// Instead of using a fixed multiple of base_size (which fails for double-spaced
+3 -1
View File
@@ -127,7 +127,9 @@ fn visual_style(line: &TextLine) -> Option<VisualStyle> {
})
}
fn roman_value(token: &str) -> Option<u32> {
/// Shared with `analysis::starts_with_numbering_prefix` so the veto
/// exemption and the heading parser agree on what a roman numeral is.
pub(super) fn roman_value(token: &str) -> Option<u32> {
if token.is_empty() || token.len() > 8 {
return None;
}
+308 -10
View File
@@ -435,6 +435,72 @@ fn revised_table_cell_indices(
.collect()
}
/// Index of candidate "body" items (larger-font attachment targets) sorted by
/// Y, so script-attachment checks scan a narrow Y window instead of the whole
/// page per candidate.
struct ScriptBodyIndex<'a> {
/// (y, item), sorted ascending by y
by_y: Vec<(f32, &'a TextItem)>,
/// widest vertical attachment window any body item can produce
max_window: f32,
}
impl<'a> ScriptBodyIndex<'a> {
fn new(items: &'a [TextItem]) -> Self {
// Smallest table-candidate font is 6pt, so any possible attachment
// target is at least 6 x 1.2 pt.
let mut by_y: Vec<(f32, &TextItem)> = items
.iter()
.filter(|i| i.font_size >= 6.0 * 1.2)
.map(|i| (i.y, i))
.collect();
by_y.sort_by(|a, b| a.0.total_cmp(&b.0));
let max_window = by_y
.iter()
.map(|(_, i)| i.font_size * 0.8)
.fold(0.0f32, f32::max);
Self { by_y, max_window }
}
/// True when a small-font item is horizontally attached to a larger-font
/// item at a script baseline offset — a sub/superscript in running text
/// or math (equation subscripts, footnote markers). Script attachments
/// are not table cells; without this filter, display equations with
/// sub/superscripts form phantom small-font table regions (e.g. TeX
/// papers where log subscripts cluster with footnote lines into a fake
/// 3-column table). A genuine baseline offset is required so same-line
/// table neighbours (a small cell beside a larger label cell) are never
/// classified as scripts.
///
/// `min_anchor_size` additionally constrains what counts as an
/// attachment target: the small-font pass accepts any sufficiently
/// larger item (0.0), while the body-font pass requires a heading-sized
/// anchor so a body-size table cell beside a slightly larger label with
/// baseline jitter is never treated as a script.
fn is_script_attachment(&self, small: &TextItem, min_anchor_size: f32) -> bool {
let attach_gap = small.font_size.max(4.0) * 0.6;
let lo = self
.by_y
.partition_point(|(y, _)| *y < small.y - self.max_window);
self.by_y[lo..]
.iter()
.take_while(|(y, _)| *y <= small.y + self.max_window)
.any(|(_, body)| {
let dy = (small.y - body.y).abs();
body.font_size >= small.font_size * 1.2
&& body.font_size >= min_anchor_size
&& dy > body.font_size * 0.05
&& dy <= body.font_size * 0.8
&& {
let gap_after_body = small.x - (body.x + body.width);
let gap_before_body = body.x - (small.x + small.width);
(-attach_gap..=attach_gap).contains(&gap_after_body)
|| (-attach_gap..=attach_gap).contains(&gap_before_body)
}
})
}
}
/// Detect tables in a set of text items from a single page
pub fn detect_tables(items: &[TextItem], base_font_size: f32, skip_body_font: bool) -> Vec<Table> {
detect_tables_with_page_width(items, base_font_size, skip_body_font, content_width(items))
@@ -483,6 +549,27 @@ pub(crate) fn detect_tables_with_page_width(
// === Pass 1: Small-font tables (existing behavior) ===
let table_font_threshold = base_font_size * 0.90;
// Mark sub/superscript attachments once per pass. They stay candidates —
// the masks only remove them from region qualification and column/row
// geometry.
//
// The two passes need different anchor thresholds. In the small-font pass
// any sufficiently larger neighbour is a plausible base for a script. In
// the body-font pass the candidates are themselves body-sized
// (0.85..1.05x), so a merely "slightly larger" neighbour is usually a bold
// label or an adjacent column header, not the base of a superscript —
// treating it as one would strip real cells out of the geometry and lose
// the table. Requiring a heading-sized anchor (>= 1.15x base) keeps the
// body pass to genuine scripts hanging off headings.
let script_index = ScriptBodyIndex::new(items);
let script_flags: Vec<bool> = items
.iter()
.map(|item| script_index.is_script_attachment(item, 0.0))
.collect();
let body_script_flags: Vec<bool> = items
.iter()
.map(|item| script_index.is_script_attachment(item, base_font_size * 1.15))
.collect();
let table_candidates: Vec<(usize, &TextItem)> = items
.iter()
.enumerate()
@@ -494,7 +581,14 @@ pub(crate) fn detect_tables_with_page_width(
.collect();
if table_candidates.len() >= 6 {
let regions = find_table_regions(&table_candidates);
// Qualify regions from non-script items: a cluster of sub/superscripts
// must not, on its own, mark out a table region.
let region_evidence: Vec<(usize, &TextItem)> = table_candidates
.iter()
.filter(|(idx, _)| !script_flags[*idx])
.cloned()
.collect();
let regions = find_table_regions(&region_evidence);
for (y_min, y_max) in regions {
let region_items: Vec<(usize, &TextItem)> = table_candidates
@@ -508,7 +602,9 @@ pub(crate) fn detect_tables_with_page_width(
}
if let Some(mut table) =
detect_table_in_region(&region_items, TableDetectionMode::SmallFont)
detect_table_in_region(&region_items, TableDetectionMode::SmallFont, &|i| {
script_flags[i]
})
{
// Try to recover body-font header row above the small-font table
recover_header_row(&mut table, items, table_font_threshold);
@@ -553,8 +649,20 @@ pub(crate) fn detect_tables_with_page_width(
body_font_low,
body_font_high,
);
// Scripts are NOT filtered out of the candidate set here, mirroring
// the small-font pass: they must stay eligible for cell assignment so
// a sub/superscript that belongs inside a table cell keeps its text.
// The heading-anchored `body_script_flags` mask removes them from
// geometry only.
if body_candidates.len() >= 6 {
let regions = find_table_regions_strict(&body_candidates);
// Same reasoning as the small-font pass: scripts do not qualify
// regions, but remain available for cell assignment within one.
let region_evidence: Vec<(usize, &TextItem)> = body_candidates
.iter()
.filter(|(idx, _)| !body_script_flags[*idx])
.cloned()
.collect();
let regions = find_table_regions_strict(&region_evidence);
log::debug!("body-font: {} strict regions found", regions.len());
for (y_min, y_max, _x_min, _x_max) in &regions {
@@ -580,7 +688,9 @@ pub(crate) fn detect_tables_with_page_width(
}
if let Some(table) =
detect_table_in_region(&region_items, TableDetectionMode::BodyFont)
detect_table_in_region(&region_items, TableDetectionMode::BodyFont, &|i| {
body_script_flags[i]
})
{
tables.push(table);
}
@@ -808,10 +918,30 @@ fn find_table_regions_strict(items: &[(usize, &TextItem)]) -> Vec<(f32, f32, f32
regions
}
/// Detect a table within a specific region
fn detect_table_in_region(items: &[(usize, &TextItem)], mode: TableDetectionMode) -> Option<Table> {
// Find column boundaries
let columns = find_column_boundaries(items, mode);
/// Detect a table within a specific region.
///
/// `is_script` marks items that are sub/superscript attachments. Those are
/// excluded from the *geometry* — they must not be able to create a column,
/// which is how equation subscript clusters used to fabricate phantom grids —
/// but they remain eligible for cell assignment, so legitimate cell content
/// (exponents in an engineering-notation table, footnote markers) stays in
/// the cell it belongs to instead of leaking out into the reading order.
fn detect_table_in_region(
items: &[(usize, &TextItem)],
mode: TableDetectionMode,
is_script: &dyn Fn(usize) -> bool,
) -> Option<Table> {
// Column geometry from non-script items only.
let geometry_items: Vec<(usize, &TextItem)> = items
.iter()
.filter(|(idx, _)| !is_script(*idx))
.cloned()
.collect();
// A region that is *entirely* scripts has no table structure at all.
if geometry_items.is_empty() {
return None;
}
let columns = find_column_boundaries(&geometry_items, mode);
let min_cols = 2;
if columns.len() < min_cols || columns.len() > 25 {
log::debug!(
@@ -822,8 +952,8 @@ fn detect_table_in_region(items: &[(usize, &TextItem)], mode: TableDetectionMode
return None;
}
// Find row boundaries
let rows = find_row_boundaries(items);
// Find row boundaries (geometry items only, same reasoning)
let rows = find_row_boundaries(&geometry_items);
let min_rows = 2;
if rows.len() < min_rows {
log::debug!(
@@ -842,6 +972,11 @@ fn detect_table_in_region(items: &[(usize, &TextItem)], mode: TableDetectionMode
);
// Verify this looks like a table: multiple items should align to columns
// Validate against ALL items, including scripts. Columns are derived from
// non-script geometry so scripts cannot *create* a column, but excluding
// them from validation too would let a region manufacture alignment: drop
// the awkward items and whatever remains looks like a tidy grid. Block
// diagrams did exactly that. Everything in the region must fit.
let col_alignment = check_column_alignment(items, &columns, mode);
let min_alignment = match mode {
TableDetectionMode::SmallFont => 0.5,
@@ -912,6 +1047,29 @@ fn detect_table_in_region(items: &[(usize, &TextItem)], mode: TableDetectionMode
cells.push(row_cells);
}
// Validation 0 (small-font pass only): reject tiny all-numeric
// fragments. A <=2-row grid whose every cell is a bare 1-2 digit number
// carries no tabular information — in practice these are
// exponent/subscript clusters from display math that happen to align.
// Body-font tables are not subject to this veto: their cells cannot be
// script glyphs.
if matches!(mode, TableDetectionMode::SmallFont) {
let nonempty_cells: Vec<&String> =
cells.iter().flatten().filter(|c| !c.is_empty()).collect();
if rows.len() <= 2
&& !nonempty_cells.is_empty()
&& nonempty_cells
.iter()
.all(|c| c.len() <= 2 && c.chars().all(|ch| ch.is_ascii_digit()))
{
log::debug!(
" validation 0 fail: tiny all-numeric fragment ({} cells)",
nonempty_cells.len()
);
return None;
}
}
// Validation 1: some rows should have content in first column.
// Use a lower threshold (25%) for tables with wrapped cells where
// continuation lines leave the first column empty.
@@ -1977,6 +2135,146 @@ fn try_add_label_column(
#[cfg(test)]
mod tests {
fn make_item(text: &str, x: f32, y: f32, font_size: f32, width: f32) -> TextItem {
TextItem {
text: text.to_string(),
x,
y,
width,
height: font_size,
font: "TestFont".to_string(),
font_size,
page: 1,
is_bold: false,
is_italic: false,
is_underline: false,
is_strikeout: false,
item_type: ItemType::Text,
mcid: None,
}
}
#[test]
fn script_attachment_detects_subscript_after_body_text() {
let body = make_item("log", 100.0, 500.0, 10.0, 15.0);
let sub = make_item("10", 115.5, 497.0, 7.0, 7.0);
let items = vec![body, sub.clone()];
assert!(ScriptBodyIndex::new(&items).is_script_attachment(&sub, 0.0));
}
#[test]
fn script_attachment_detects_superscript_footnote_marker() {
let body = make_item("Hartley", 200.0, 500.0, 10.0, 35.0);
let sup = make_item("2", 235.8, 504.0, 6.6, 3.5);
let items = vec![body, sup.clone()];
assert!(ScriptBodyIndex::new(&items).is_script_attachment(&sup, 0.0));
}
#[test]
fn script_attachment_ignores_small_cell_far_from_body_text() {
let body = make_item("Revenue", 100.0, 500.0, 10.0, 40.0);
let cell = make_item("1,234", 180.0, 500.0, 7.0, 20.0);
let items = vec![body, cell.clone()];
assert!(!ScriptBodyIndex::new(&items).is_script_attachment(&cell, 0.0));
}
#[test]
fn body_pass_anchor_spares_cells_beside_slightly_larger_labels() {
// A body-font table cell (10pt) sitting beside a slightly larger,
// NON-heading label (12.5pt) with a little baseline jitter. The
// small-font pass treats any larger neighbour as a possible script
// base, but the body pass must not: at body sizes a slightly larger
// neighbour is a bold label or column header, and flagging the cell
// would strip it out of the table geometry and lose the table.
// Cell at the low end of the body band (0.85x base) beside a 10.5pt
// label. 10.5 clears the inherent 1.2x-of-cell rule (10.2) but falls
// below the body pass's heading anchor (11.5), which is exactly the
// band where the two masks must disagree.
let label = make_item("Revenue", 100.0, 500.0, 10.5, 40.0);
let cell = make_item("1,234", 141.0, 496.5, 8.5, 22.0);
let items = vec![label, cell.clone()];
let index = ScriptBodyIndex::new(&items);
let base = 10.0;
assert!(
index.is_script_attachment(&cell, 0.0),
"small-font pass anchor should still see this as an attachment"
);
assert!(
!index.is_script_attachment(&cell, base * 1.15),
"body pass must not treat a cell beside a slightly larger label \
as a script — that removes real cells from the geometry"
);
// A genuine heading-sized anchor still qualifies in the body pass.
let heading = make_item("Section", 100.0, 500.0, 20.0, 60.0);
let sup = make_item("3", 161.0, 508.0, 10.0, 5.0);
let h_items = vec![heading, sup.clone()];
assert!(
ScriptBodyIndex::new(&h_items).is_script_attachment(&sup, base * 1.15),
"script hanging off a heading must still be excluded in the body pass"
);
}
#[test]
fn script_attachment_ignores_same_baseline_neighbor_cell() {
// A small cell beside a larger label on the SAME baseline is a table
// layout, not a subscript — a genuine baseline offset is required.
let label = make_item("Total", 100.0, 500.0, 10.0, 25.0);
let cell = make_item("42", 127.0, 500.0, 7.5, 9.0);
let items = vec![label, cell.clone()];
assert!(!ScriptBodyIndex::new(&items).is_script_attachment(&cell, 0.0));
}
#[test]
fn script_attachment_ignores_neighbor_on_different_line() {
let body = make_item("Header", 100.0, 500.0, 10.0, 30.0);
let cell = make_item("42", 131.0, 486.0, 7.0, 10.0);
let items = vec![body, cell.clone()];
assert!(!ScriptBodyIndex::new(&items).is_script_attachment(&cell, 0.0));
}
/// Equation-subscript + footnote layout from Shannon entropy.pdf page 1,
/// with real coordinates. Without the larger-font anchors the small items
/// alone DO form a phantom table — proving the layout reaches detection —
/// and adding the anchors must suppress it.
fn shannon_page1_small_items() -> Vec<TextItem> {
vec![
make_item("2", 267.4, 133.9, 7.4, 3.7),
make_item("10", 306.2, 133.9, 7.4, 7.4),
make_item("10", 342.7, 133.9, 7.4, 7.4),
make_item("10", 325.0, 118.9, 7.4, 7.4),
make_item("Bell System Technical Journal,", 295.7, 101.9, 8.0, 95.0),
make_item(
"April 1924, p. 324; Certain Topics in",
396.7,
101.9,
8.0,
130.0,
),
make_item("v. 47, April 1928, p. 617.", 250.9, 92.5, 8.0, 90.0),
make_item("Bell System Technical Journal,", 264.2, 82.6, 8.0, 95.0),
make_item("July 1928, p. 535.", 364.3, 82.6, 8.0, 65.0),
]
}
#[test]
fn equation_scripts_do_not_form_phantom_table() {
let bare = shannon_page1_small_items();
assert!(
!detect_tables(&bare, 10.0, false).is_empty(),
"test layout must form a phantom table when the filter cannot fire"
);
let mut items = shannon_page1_small_items();
items.push(make_item("log", 253.0, 137.0, 10.0, 13.5));
items.push(make_item("log", 291.5, 137.0, 10.0, 13.5));
items.push(make_item("log", 328.0, 137.0, 10.0, 13.5));
items.push(make_item("log", 310.3, 122.0, 10.0, 13.5));
let tables = detect_tables(&items, 10.0, false);
assert!(
tables.is_empty(),
"equation scripts + footnotes must not become a table: {tables:?}"
);
}
use super::*;
use crate::types::ItemType;