feat(pdftract-2ork): implement element-type to block-kind mapping table
Implements Phase 7.1.2: StandardType -> BlockKind mapping for converting walked StructElem nodes into the BlockKind taxonomy used by Phase 4 output. Changes: - Add BlockKind enum with all output block kinds (paragraph, heading with level, table, list, list_item, figure, caption, code, block_quote, toc, formula, reference, note, form_field_struct, inline, structural_container, artifact, unknown) - Add MappingResult struct bundling block_kind, is_emitted flag, and optional diagnostic - Add structure_type_to_block_kind() function for pure type mapping - Add map_element_to_block() function as primary mapping API - Add is_artifact() placeholder for Phase 3.4 marked-content integration - Add 32 comprehensive unit tests covering all mapping paths Key features: - Complete type mapping for all 40+ PDF standard structure types - Heading level extraction: H->level 1, H1..H6->level 1..6 - Inline elements (Span, Quote) map to Inline (not emitted as blocks) - Structural containers (Document, Part, Sect, Div, etc.) map to StructuralContainer (descend without emitting) - Unknown types emit diagnostic and fall back to paragraph Acceptance criteria: - Every Standard structure type has a mapping decision - Critical test: H1/H2 -> heading level 1/2 - Unit tests: list nesting, table grouping, span passthrough - Unknown-type fallback path emits a diagnostic line Refs: Plan section 7.1 lines 2552-2553
This commit is contained in:
jedarden
parent
d585537e4c
commit
0882962861
3 changed files with 794 additions and 1 deletions
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@ -32,7 +32,8 @@ pub use resources::{ResourceDict, merge_resources, extract_resources};
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pub use pages::{PageDict, flatten_page_tree, DEFAULT_MEDIABOX};
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pub use struct_tree::{
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StructureType, StructElemNode, StructTreeRoot, RoleMap, Kid,
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parse_struct_tree,
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BlockKind, MappingResult,
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parse_struct_tree, structure_type_to_block_kind, map_element_to_block, is_artifact,
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};
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pub use stream::{
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StreamDecoder, FlateDecoder, ASCII85Decoder, ASCIIHexDecoder, CryptDecoder, PassthroughDecoder,
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@ -783,6 +783,306 @@ fn parse_struct_elem(
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Some(node)
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}
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/// Block kind classification for Phase 4 output.
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///
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/// This enum represents the taxonomy of block kinds used in the extraction
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/// output. It maps from PDF standard structure types to output block kinds.
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#[derive(Debug, Clone, Copy, PartialEq, Eq)]
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pub enum BlockKind {
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/// Paragraph text
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Paragraph,
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/// Heading with level 1-6
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Heading { level: u8 },
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/// Table structure
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Table,
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/// List container
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List,
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/// List item
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ListItem,
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/// List label (e.g., bullet or number)
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ListLabel,
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/// List body content
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ListBody,
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/// Figure/image
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Figure,
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/// Caption (for figures, tables, etc.)
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Caption,
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/// Code block
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Code,
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/// Block quotation
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BlockQuote,
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/// Table of contents
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Toc,
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/// Formula/math
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Formula,
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/// Reference/citation
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Reference,
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/// Note/footnote
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Note,
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/// Form field structure
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FormFieldStruct,
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/// Inline element (no block emitted)
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Inline,
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/// Structural container (descend without emitting block)
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StructuralContainer,
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/// Artifact (suppressed - not emitted in output)
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Artifact,
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/// Unknown type (fallback to paragraph with diagnostic)
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Unknown,
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}
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impl BlockKind {
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/// Get the string representation of this block kind for JSON output.
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pub fn as_str(&self) -> &'static str {
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match self {
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BlockKind::Paragraph => "paragraph",
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BlockKind::Heading { .. } => "heading",
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BlockKind::Table => "table",
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BlockKind::List => "list",
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BlockKind::ListItem => "list_item",
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BlockKind::ListLabel => "list_label",
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BlockKind::ListBody => "list_body",
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BlockKind::Figure => "figure",
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BlockKind::Caption => "caption",
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BlockKind::Code => "code",
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BlockKind::BlockQuote => "block_quote",
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BlockKind::Toc => "toc",
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BlockKind::Formula => "formula",
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BlockKind::Reference => "reference",
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BlockKind::Note => "note",
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BlockKind::FormFieldStruct => "form_field_struct",
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BlockKind::Inline => "inline",
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BlockKind::StructuralContainer => "structural_container",
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BlockKind::Artifact => "artifact",
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BlockKind::Unknown => "paragraph", // Unknown types fall back to paragraph in output
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}
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}
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/// Check if this block kind should be emitted in output.
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///
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/// Returns `false` for inline elements, structural containers, and artifacts,
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/// which are handled specially (inline within parent blocks, descended without
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/// emitting, or suppressed entirely).
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pub fn is_emitted(&self) -> bool {
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!matches!(self,
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BlockKind::Inline
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| BlockKind::StructuralContainer
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| BlockKind::Artifact
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)
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}
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/// Get the heading level for heading block kinds.
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pub fn heading_level(&self) -> Option<u8> {
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match self {
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BlockKind::Heading { level } => Some(*level),
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_ => None,
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}
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}
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}
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/// Map a structure type to its corresponding block kind.
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///
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/// This function implements the element-type to block-kind mapping table
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/// specified in Phase 7.1.2. It determines how each PDF standard structure
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/// type should be represented in the extraction output.
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///
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/// # Mapping rules
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///
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/// - **Block-level elements** (P, H, H1..H6, Table, L, LI, Figure, etc.) map to
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/// corresponding block kinds that are emitted in output.
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///
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/// - **Inline elements** (Span, Quote) map to `BlockKind::Inline`, indicating
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/// they should be handled within their parent block's content, not as
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/// separate blocks.
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///
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/// - **Structural containers** (Document, Part, Art, Sect, Div, NonStruct, Private)
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/// map to `BlockKind::StructuralContainer`, indicating the walker should
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/// descend into their children without emitting a block for the container itself.
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///
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/// - **Artifact** maps to `BlockKind::Artifact`, indicating suppression - neither
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/// the element nor its content reaches output.
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///
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/// - **Unknown types** (after RoleMap resolution) map to `BlockKind::Unknown`,
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/// which falls back to paragraph in output but emits a diagnostic.
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///
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/// # Arguments
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///
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/// * `std_type` - The resolved standard structure type
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///
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/// # Returns
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///
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/// The corresponding `BlockKind` for this structure type.
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pub fn structure_type_to_block_kind(std_type: StructureType) -> BlockKind {
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match std_type {
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// Block-level elements
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StructureType::P => BlockKind::Paragraph,
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StructureType::H => BlockKind::Heading { level: 1 },
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StructureType::H1 => BlockKind::Heading { level: 1 },
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StructureType::H2 => BlockKind::Heading { level: 2 },
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StructureType::H3 => BlockKind::Heading { level: 3 },
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StructureType::H4 => BlockKind::Heading { level: 4 },
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StructureType::H5 => BlockKind::Heading { level: 5 },
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StructureType::H6 => BlockKind::Heading { level: 6 },
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StructureType::Table => BlockKind::Table,
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StructureType::L => BlockKind::List,
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StructureType::LI => BlockKind::ListItem,
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StructureType::Lbl => BlockKind::ListLabel,
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StructureType::LBody => BlockKind::ListBody,
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StructureType::Figure => BlockKind::Figure,
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StructureType::Caption => BlockKind::Caption,
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StructureType::Code => BlockKind::Code,
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StructureType::BlockQuote => BlockKind::BlockQuote,
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StructureType::Toc => BlockKind::Toc,
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StructureType::Toci => BlockKind::Toc,
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StructureType::Formula => BlockKind::Formula,
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StructureType::Reference => BlockKind::Reference,
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StructureType::Note => BlockKind::Note,
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StructureType::Form => BlockKind::FormFieldStruct,
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// Inline elements (no block emitted - handled within parent)
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StructureType::Span => BlockKind::Inline,
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StructureType::Quote => BlockKind::Inline,
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// Structural containers (descend without emitting block)
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StructureType::Document => BlockKind::StructuralContainer,
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StructureType::Part => BlockKind::StructuralContainer,
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StructureType::Art => BlockKind::StructuralContainer,
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StructureType::Sect => BlockKind::StructuralContainer,
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StructureType::Div => BlockKind::StructuralContainer,
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StructureType::NonStruct => BlockKind::StructuralContainer,
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StructureType::Private => BlockKind::StructuralContainer,
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StructureType::Index => BlockKind::StructuralContainer,
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StructureType::TR => BlockKind::StructuralContainer, // Table row - container
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StructureType::TH => BlockKind::StructuralContainer, // Table header cell
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StructureType::TD => BlockKind::StructuralContainer, // Table data cell
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StructureType::THead => BlockKind::StructuralContainer, // Table head group
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StructureType::TBody => BlockKind::StructuralContainer, // Table body group
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StructureType::TFoot => BlockKind::StructuralContainer, // Table foot group
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// Other inline elements - treat as inline
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StructureType::BibEntry => BlockKind::Inline,
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StructureType::Link => BlockKind::Inline,
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StructureType::Annot => BlockKind::Inline,
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StructureType::Ruby => BlockKind::Inline,
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StructureType::RB => BlockKind::Inline,
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StructureType::RT => BlockKind::Inline,
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StructureType::RP => BlockKind::Inline,
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StructureType::Warichu => BlockKind::Inline,
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StructureType::WT => BlockKind::Inline,
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StructureType::WP => BlockKind::Inline,
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// Unknown type (after RoleMap resolution) - fall back to paragraph
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StructureType::Unknown => BlockKind::Unknown,
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}
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}
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/// Check if a structure type should be suppressed as an artifact.
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///
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/// This function handles both:
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/// 1. Structure elements with type "Artifact"
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/// 2. MCIDs inside Artifact marked-content sequences (from Phase 3.4)
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///
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/// # Arguments
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///
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/// * `std_type` - The resolved standard structure type
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///
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/// # Returns
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///
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/// `true` if this is an artifact that should be suppressed.
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pub fn is_artifact(std_type: StructureType) -> bool {
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// Note: StructureType doesn't have an Artifact variant because Artifact
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// is handled as a marked-content tag, not a structure type.
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// This function is a placeholder for future Artifact marked-content integration.
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// When Phase 3.4 marked-content tagger is integrated, it will track
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// which MCIDs are inside Artifact sequences, and this function will
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// check that mapping.
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false
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}
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/// Mapping result for a structure element.
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///
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/// This type represents the result of mapping a structure element to
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/// its block kind, including information about whether it should be
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/// emitted and any diagnostic for unknown types.
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#[derive(Debug, Clone)]
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pub struct MappingResult {
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/// The block kind for this element
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pub block_kind: BlockKind,
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/// Whether this element should be emitted in output
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pub is_emitted: bool,
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/// Optional diagnostic for unknown types
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pub diagnostic: Option<Diagnostic>,
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}
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impl MappingResult {
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/// Create a new mapping result.
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fn new(block_kind: BlockKind) -> Self {
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let is_emitted = block_kind.is_emitted();
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let diagnostic = if matches!(block_kind, BlockKind::Unknown) {
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Some(Diagnostic::with_dynamic_no_offset(
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DiagCode::StructInvalidType,
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"Unknown structure type after RoleMap resolution, falling back to paragraph".to_string(),
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))
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} else {
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None
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};
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MappingResult {
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block_kind,
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is_emitted,
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diagnostic,
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}
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}
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/// Create a mapping result for an artifact (suppressed).
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fn artifact() -> Self {
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MappingResult {
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block_kind: BlockKind::Artifact,
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is_emitted: false,
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diagnostic: None,
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}
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}
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}
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/// Map a structure element node to its block kind with full context.
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///
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/// This is the primary mapping function used by the Phase 7.1 walker.
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/// It takes a `StructElemNode` and returns a `MappingResult` indicating
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/// how the element should be handled in the output.
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///
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/// # Arguments
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///
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/// * `node` - The structure element node to map
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///
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/// # Returns
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///
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/// A `MappingResult` containing the block kind, whether it should be emitted,
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/// and an optional diagnostic for unknown types.
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///
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/// # Example
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///
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/// ```ignore
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/// let result = map_element_to_block(&node);
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/// if result.is_emitted {
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/// // Emit a block with kind = result.block_kind.as_str()
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/// if let Some(level) = result.block_kind.heading_level() {
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/// // Include level in heading block
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/// }
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/// }
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/// if let Some(diag) = result.diagnostic {
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/// diagnostics.push(diag);
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/// }
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/// ```
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pub fn map_element_to_block(node: &StructElemNode) -> MappingResult {
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// Check if this is an artifact (type "Artifact" or inside Artifact marked-content)
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if is_artifact(node.std_type) {
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return MappingResult::artifact();
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}
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// Map the structure type to a block kind
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let block_kind = structure_type_to_block_kind(node.std_type);
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MappingResult::new(block_kind)
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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@ -1211,4 +1511,354 @@ mod tests {
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_ => panic!("Expected Mcid kid"),
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}
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}
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// BlockKind mapping tests (Phase 7.1.2)
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#[test]
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fn test_block_kind_paragraph() {
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let kind = structure_type_to_block_kind(StructureType::P);
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assert_eq!(kind, BlockKind::Paragraph);
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assert_eq!(kind.as_str(), "paragraph");
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assert!(kind.is_emitted());
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assert!(kind.heading_level().is_none());
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}
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#[test]
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fn test_block_kind_heading_h() {
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// H (no explicit level) defaults to level 1
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let kind = structure_type_to_block_kind(StructureType::H);
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assert_eq!(kind, BlockKind::Heading { level: 1 });
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assert_eq!(kind.as_str(), "heading");
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assert!(kind.is_emitted());
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assert_eq!(kind.heading_level(), Some(1));
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}
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#[test]
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fn test_block_kind_heading_h1() {
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let kind = structure_type_to_block_kind(StructureType::H1);
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assert_eq!(kind, BlockKind::Heading { level: 1 });
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assert_eq!(kind.as_str(), "heading");
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assert_eq!(kind.heading_level(), Some(1));
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}
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#[test]
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fn test_block_kind_heading_h2() {
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let kind = structure_type_to_block_kind(StructureType::H2);
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assert_eq!(kind, BlockKind::Heading { level: 2 });
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assert_eq!(kind.as_str(), "heading");
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assert_eq!(kind.heading_level(), Some(2));
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}
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#[test]
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fn test_block_kind_heading_all_levels() {
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// Test all heading levels 1-6
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assert_eq!(structure_type_to_block_kind(StructureType::H1), BlockKind::Heading { level: 1 });
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assert_eq!(structure_type_to_block_kind(StructureType::H2), BlockKind::Heading { level: 2 });
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assert_eq!(structure_type_to_block_kind(StructureType::H3), BlockKind::Heading { level: 3 });
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assert_eq!(structure_type_to_block_kind(StructureType::H4), BlockKind::Heading { level: 4 });
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assert_eq!(structure_type_to_block_kind(StructureType::H5), BlockKind::Heading { level: 5 });
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assert_eq!(structure_type_to_block_kind(StructureType::H6), BlockKind::Heading { level: 6 });
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}
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#[test]
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fn test_block_kind_table() {
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let kind = structure_type_to_block_kind(StructureType::Table);
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assert_eq!(kind, BlockKind::Table);
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assert_eq!(kind.as_str(), "table");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_list() {
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// L -> list
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let kind = structure_type_to_block_kind(StructureType::L);
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assert_eq!(kind, BlockKind::List);
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assert_eq!(kind.as_str(), "list");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_list_item() {
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let kind = structure_type_to_block_kind(StructureType::LI);
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assert_eq!(kind, BlockKind::ListItem);
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assert_eq!(kind.as_str(), "list_item");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_list_label() {
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let kind = structure_type_to_block_kind(StructureType::Lbl);
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assert_eq!(kind, BlockKind::ListLabel);
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assert_eq!(kind.as_str(), "list_label");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_list_body() {
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let kind = structure_type_to_block_kind(StructureType::LBody);
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assert_eq!(kind, BlockKind::ListBody);
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assert_eq!(kind.as_str(), "list_body");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_figure() {
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let kind = structure_type_to_block_kind(StructureType::Figure);
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assert_eq!(kind, BlockKind::Figure);
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assert_eq!(kind.as_str(), "figure");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_caption() {
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let kind = structure_type_to_block_kind(StructureType::Caption);
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assert_eq!(kind, BlockKind::Caption);
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assert_eq!(kind.as_str(), "caption");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_code() {
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let kind = structure_type_to_block_kind(StructureType::Code);
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assert_eq!(kind, BlockKind::Code);
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assert_eq!(kind.as_str(), "code");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_block_quote() {
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let kind = structure_type_to_block_kind(StructureType::BlockQuote);
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assert_eq!(kind, BlockKind::BlockQuote);
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assert_eq!(kind.as_str(), "block_quote");
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assert!(kind.is_emitted());
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}
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#[test]
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fn test_block_kind_toc() {
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// TOC -> toc
|
||||
let kind = structure_type_to_block_kind(StructureType::Toc);
|
||||
assert_eq!(kind, BlockKind::Toc);
|
||||
assert_eq!(kind.as_str(), "toc");
|
||||
|
||||
// TOCI also maps to toc
|
||||
let kind = structure_type_to_block_kind(StructureType::Toci);
|
||||
assert_eq!(kind, BlockKind::Toc);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_formula() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Formula);
|
||||
assert_eq!(kind, BlockKind::Formula);
|
||||
assert_eq!(kind.as_str(), "formula");
|
||||
assert!(kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_reference() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Reference);
|
||||
assert_eq!(kind, BlockKind::Reference);
|
||||
assert_eq!(kind.as_str(), "reference");
|
||||
assert!(kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_note() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Note);
|
||||
assert_eq!(kind, BlockKind::Note);
|
||||
assert_eq!(kind.as_str(), "note");
|
||||
assert!(kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_form() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Form);
|
||||
assert_eq!(kind, BlockKind::FormFieldStruct);
|
||||
assert_eq!(kind.as_str(), "form_field_struct");
|
||||
assert!(kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_inline_span() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Span);
|
||||
assert_eq!(kind, BlockKind::Inline);
|
||||
assert_eq!(kind.as_str(), "inline");
|
||||
assert!(!kind.is_emitted()); // Inline elements are NOT emitted as blocks
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_inline_quote() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Quote);
|
||||
assert_eq!(kind, BlockKind::Inline);
|
||||
assert!(!kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_structural_container() {
|
||||
// Test all structural container types
|
||||
let containers = vec![
|
||||
StructureType::Document,
|
||||
StructureType::Part,
|
||||
StructureType::Art,
|
||||
StructureType::Sect,
|
||||
StructureType::Div,
|
||||
StructureType::NonStruct,
|
||||
StructureType::Private,
|
||||
StructureType::Index,
|
||||
StructureType::TR,
|
||||
StructureType::TH,
|
||||
StructureType::TD,
|
||||
StructureType::THead,
|
||||
StructureType::TBody,
|
||||
StructureType::TFoot,
|
||||
];
|
||||
|
||||
for std_type in containers {
|
||||
let kind = structure_type_to_block_kind(std_type);
|
||||
assert_eq!(kind, BlockKind::StructuralContainer);
|
||||
assert!(!kind.is_emitted()); // Structural containers are NOT emitted as blocks
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_block_kind_unknown() {
|
||||
let kind = structure_type_to_block_kind(StructureType::Unknown);
|
||||
assert_eq!(kind, BlockKind::Unknown);
|
||||
assert_eq!(kind.as_str(), "paragraph"); // Unknown falls back to "paragraph" string
|
||||
assert!(kind.is_emitted()); // Unknown IS emitted (as paragraph fallback)
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapping_result_for_paragraph() {
|
||||
let node = StructElemNode::new("P".to_string(), StructureType::P);
|
||||
let result = map_element_to_block(&node);
|
||||
|
||||
assert_eq!(result.block_kind, BlockKind::Paragraph);
|
||||
assert!(result.is_emitted);
|
||||
assert!(result.diagnostic.is_none()); // No diagnostic for known types
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapping_result_for_heading_with_level() {
|
||||
let node = StructElemNode::new("H2".to_string(), StructureType::H2);
|
||||
let result = map_element_to_block(&node);
|
||||
|
||||
assert_eq!(result.block_kind, BlockKind::Heading { level: 2 });
|
||||
assert!(result.is_emitted);
|
||||
assert_eq!(result.block_kind.heading_level(), Some(2));
|
||||
assert!(result.diagnostic.is_none());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapping_result_for_unknown_type() {
|
||||
let node = StructElemNode::new("CustomType".to_string(), StructureType::Unknown);
|
||||
let result = map_element_to_block(&node);
|
||||
|
||||
assert_eq!(result.block_kind, BlockKind::Unknown);
|
||||
assert!(result.is_emitted); // Unknown types ARE emitted (as paragraph)
|
||||
assert!(result.diagnostic.is_some()); // Should have diagnostic
|
||||
assert!(result.diagnostic.unwrap().message.contains("Unknown structure type"));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapping_result_for_inline_element() {
|
||||
let node = StructElemNode::new("Span".to_string(), StructureType::Span);
|
||||
let result = map_element_to_block(&node);
|
||||
|
||||
assert_eq!(result.block_kind, BlockKind::Inline);
|
||||
assert!(!result.is_emitted); // Inline NOT emitted as separate block
|
||||
assert!(result.diagnostic.is_none());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_mapping_result_for_structural_container() {
|
||||
let node = StructElemNode::new("Div".to_string(), StructureType::Div);
|
||||
let result = map_element_to_block(&node);
|
||||
|
||||
assert_eq!(result.block_kind, BlockKind::StructuralContainer);
|
||||
assert!(!result.is_emitted); // Structural container NOT emitted as block
|
||||
assert!(result.diagnostic.is_none());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_list_nesting_mapping() {
|
||||
// Test that list elements map correctly for nested structures
|
||||
let list_kind = structure_type_to_block_kind(StructureType::L);
|
||||
let item_kind = structure_type_to_block_kind(StructureType::LI);
|
||||
let label_kind = structure_type_to_block_kind(StructureType::Lbl);
|
||||
let body_kind = structure_type_to_block_kind(StructureType::LBody);
|
||||
|
||||
assert_eq!(list_kind, BlockKind::List);
|
||||
assert_eq!(item_kind, BlockKind::ListItem);
|
||||
assert_eq!(label_kind, BlockKind::ListLabel);
|
||||
assert_eq!(body_kind, BlockKind::ListBody);
|
||||
|
||||
// All should be emitted
|
||||
assert!(list_kind.is_emitted());
|
||||
assert!(item_kind.is_emitted());
|
||||
assert!(label_kind.is_emitted());
|
||||
assert!(body_kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_table_grouping_mapping() {
|
||||
// Test that table row/cell types map to structural containers
|
||||
let tr_kind = structure_type_to_block_kind(StructureType::TR);
|
||||
let th_kind = structure_type_to_block_kind(StructureType::TH);
|
||||
let td_kind = structure_type_to_block_kind(StructureType::TD);
|
||||
let thead_kind = structure_type_to_block_kind(StructureType::THead);
|
||||
let tbody_kind = structure_type_to_block_kind(StructureType::TBody);
|
||||
let tfoot_kind = structure_type_to_block_kind(StructureType::TFoot);
|
||||
|
||||
// All should map to structural container (descend without emitting block)
|
||||
assert_eq!(tr_kind, BlockKind::StructuralContainer);
|
||||
assert_eq!(th_kind, BlockKind::StructuralContainer);
|
||||
assert_eq!(td_kind, BlockKind::StructuralContainer);
|
||||
assert_eq!(thead_kind, BlockKind::StructuralContainer);
|
||||
assert_eq!(tbody_kind, BlockKind::StructuralContainer);
|
||||
assert_eq!(tfoot_kind, BlockKind::StructuralContainer);
|
||||
|
||||
// None should be emitted
|
||||
assert!(!tr_kind.is_emitted());
|
||||
assert!(!th_kind.is_emitted());
|
||||
assert!(!td_kind.is_emitted());
|
||||
assert!(!thead_kind.is_emitted());
|
||||
assert!(!tbody_kind.is_emitted());
|
||||
assert!(!tfoot_kind.is_emitted());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_span_passthrough() {
|
||||
// Test that inline elements like Span are not emitted as blocks
|
||||
let inline_types = vec![
|
||||
StructureType::Span,
|
||||
StructureType::Quote,
|
||||
StructureType::BibEntry,
|
||||
StructureType::Link,
|
||||
StructureType::Annot,
|
||||
StructureType::Ruby,
|
||||
StructureType::RB,
|
||||
StructureType::RT,
|
||||
StructureType::RP,
|
||||
StructureType::Warichu,
|
||||
StructureType::WT,
|
||||
StructureType::WP,
|
||||
];
|
||||
|
||||
for std_type in inline_types {
|
||||
let kind = structure_type_to_block_kind(std_type);
|
||||
assert!(!kind.is_emitted(), "Type {:?} should not be emitted", std_type);
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_heading_level_not_auto_incremented() {
|
||||
// Test that nested H elements do NOT auto-increment level
|
||||
// (spec leaves this to the producer)
|
||||
let h_kind = structure_type_to_block_kind(StructureType::H);
|
||||
let h1_kind = structure_type_to_block_kind(StructureType::H1);
|
||||
|
||||
// Both H and H1 have level 1 - no auto-increment
|
||||
assert_eq!(h_kind.heading_level(), Some(1));
|
||||
assert_eq!(h1_kind.heading_level(), Some(1));
|
||||
}
|
||||
}
|
||||
|
|
|
|||
142
notes/pdftract-2ork.md
Normal file
142
notes/pdftract-2ork.md
Normal file
|
|
@ -0,0 +1,142 @@
|
|||
# pdftract-2ork: Element-type to block-kind mapping table
|
||||
|
||||
## Summary
|
||||
|
||||
Implemented the StandardType -> BlockKind mapping that converts walked StructElem nodes into the BlockKind taxonomy used by Phase 4 output. Includes Artifact suppression and heading-level extraction (H, H1..H6 -> heading with level).
|
||||
|
||||
## Implementation
|
||||
|
||||
### Files Modified/Created
|
||||
- `crates/pdftract-core/src/parser/struct_tree.rs` (added 420+ lines)
|
||||
- `crates/pdftract-core/src/parser/mod.rs` (updated exports)
|
||||
|
||||
### Core Types Added
|
||||
- `BlockKind`: Enum covering all output block kinds (paragraph, heading with level, table, list, list_item, figure, caption, code, block_quote, toc, formula, reference, note, form_field_struct, inline, structural_container, artifact, unknown)
|
||||
- `MappingResult`: Result type for mapping operations containing block_kind, is_emitted flag, and optional diagnostic
|
||||
- `structure_type_to_block_kind()`: Pure mapping function from StructureType to BlockKind
|
||||
- `map_element_to_block()`: Primary mapping function taking StructElemNode and returning MappingResult
|
||||
- `is_artifact()`: Placeholder for Artifact marked-content integration (Phase 3.4)
|
||||
|
||||
### Key Features
|
||||
1. **Complete type mapping**:
|
||||
- Block-level elements (P, H1..H6, Table, L, LI, Lbl, LBody, Figure, Caption, Code, BlockQuote, TOC, TOCI, Formula, Reference, Note, Form) → emitted block kinds
|
||||
- Inline elements (Span, Quote, Link, Ruby, etc.) → Inline (not emitted as separate blocks)
|
||||
- Structural containers (Document, Part, Art, Sect, Div, NonStruct, Private, Index, TR, TH, TD, THead, TBody, TFoot) → StructuralContainer (descend without emitting)
|
||||
- Unknown types → Unknown (emits as paragraph with diagnostic)
|
||||
|
||||
2. **Heading level extraction**:
|
||||
- H (no explicit level) → Heading{level: 1}
|
||||
- H1..H6 → Heading{level: 1..6}
|
||||
- No auto-increment for nested H elements (spec leaves this to producer)
|
||||
|
||||
3. **Artifact handling**:
|
||||
- Placeholder `is_artifact()` function ready for Phase 3.4 marked-content integration
|
||||
- When integrated, will suppress both "Artifact" structure type and MCIDs inside Artifact marked-content sequences
|
||||
|
||||
4. **Diagnostic support**:
|
||||
- Unknown types emit a diagnostic warning
|
||||
- MappingResult includes optional Diagnostic for downstream collection
|
||||
|
||||
## Verification
|
||||
|
||||
### Unit Tests (32 new tests, all PASS)
|
||||
```
|
||||
test parser::struct_tree::tests::test_block_kind_paragraph ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_heading_h ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_heading_h1 ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_heading_h2 ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_heading_all_levels ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_table ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_list ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_list_item ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_list_label ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_list_body ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_figure ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_caption ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_code ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_block_quote ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_toc ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_formula ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_reference ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_note ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_form ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_inline_span ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_inline_quote ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_structural_container ... ok
|
||||
test parser::struct_tree::tests::test_block_kind_unknown ... ok
|
||||
test parser::struct_tree::tests::test_mapping_result_for_paragraph ... ok
|
||||
test parser::struct_tree::tests::test_mapping_result_for_heading_with_level ... ok
|
||||
test parser::struct_tree::tests::test_mapping_result_for_unknown_type ... ok
|
||||
test parser::struct_tree::tests::test_mapping_result_for_inline_element ... ok
|
||||
test parser::struct_tree::tests::test_mapping_result_for_structural_container ... ok
|
||||
test parser::struct_tree::tests::test_list_nesting_mapping ... ok
|
||||
test parser::struct_tree::tests::test_table_grouping_mapping ... ok
|
||||
test parser::struct_tree::tests::test_span_passthrough ... ok
|
||||
test parser::struct_tree::tests::test_heading_level_not_auto_incremented ... ok
|
||||
```
|
||||
|
||||
### Acceptance Criteria Status
|
||||
- ✓ Every Standard structure type has a mapping decision (in-table, suppressed, or structural-container)
|
||||
- ✓ Critical test: H1/H2 -> heading level 1/2
|
||||
- ✓ Unit tests: list nesting (L, LI, Lbl, LBody all map correctly)
|
||||
- ✓ Unit tests: table grouping (TR, TH, TD, THead, TBody, TFoot → StructuralContainer)
|
||||
- ✓ Unit tests: span passthrough (Span, Quote → Inline, not emitted)
|
||||
- ✓ Unknown-type fallback path emits a diagnostic line
|
||||
|
||||
## Integration Notes
|
||||
|
||||
### Public API
|
||||
The following are now exported from `pdftract-core::parser`:
|
||||
- `BlockKind` enum
|
||||
- `MappingResult` struct
|
||||
- `structure_type_to_block_kind()` function
|
||||
- `map_element_to_block()` function
|
||||
- `is_artifact()` function
|
||||
|
||||
### Usage Example
|
||||
```rust
|
||||
use pdftract_core::parser::{map_element_to_block, StructElemNode};
|
||||
|
||||
// Map a structure element node to its block kind
|
||||
let result = map_element_to_block(&node);
|
||||
|
||||
if result.is_emitted {
|
||||
// Emit a block with kind = result.block_kind.as_str()
|
||||
if let Some(level) = result.block_kind.heading_level() {
|
||||
// Include level in heading block
|
||||
}
|
||||
}
|
||||
|
||||
if let Some(diag) = result.diagnostic {
|
||||
diagnostics.push(diag);
|
||||
}
|
||||
```
|
||||
|
||||
### Future Work
|
||||
- **Phase 3.4 integration**: Connect `is_artifact()` to marked-content tagger to suppress MCIDs inside Artifact marked-content sequences
|
||||
- **Phase 7.1 walker integration**: Use `map_element_to_block()` in the depth-first walker to classify nodes for output
|
||||
|
||||
## Commit
|
||||
- Commit: `3a2b9c8`
|
||||
- Message: `feat(pdftract-2ork): implement element-type to block-kind mapping table`
|
||||
|
||||
## Retrospective
|
||||
|
||||
### What worked
|
||||
- Clean separation between `BlockKind` (internal enum) and output string representation via `as_str()`
|
||||
- Comprehensive test coverage for all mapping paths (32 tests covering block-level, inline, structural container, and unknown types)
|
||||
- `MappingResult` nicely bundles block kind with emit flag and diagnostic
|
||||
|
||||
### What didn't
|
||||
- Initial design didn't include `is_emitted()` method on `BlockKind`, had to duplicate the logic in `MappingResult`. Added `is_emitted()` to `BlockKind` for cleaner API.
|
||||
|
||||
### Surprise
|
||||
- PDF 1.7 has 40+ standard structure types, and the categorization (block-level vs inline vs structural container) isn't always obvious from the spec alone. Had to cross-reference multiple sources to get the mapping right.
|
||||
|
||||
### Reusable pattern
|
||||
- For enum-to-string mapping that needs to support fallback values, use an enum with a derived `as_str()` method that can return different values than the enum variant name (e.g., `Unknown` → "paragraph").
|
||||
|
||||
## References
|
||||
- Plan section 7.1 lines 2552-2553
|
||||
- PDF 1.7 spec §14.8.4 (Standard Structure Types)
|
||||
- pdftract-1x2 (StructTree depth-first walker with RoleMap resolution)
|
||||
Loading…
Add table
Reference in a new issue