Module dtd 

DTD validation engine.

Captures <!ELEMENT> and <!ATTLIST> declarations during parse, then validates a parsed Document against them.

Scope

Covers the subset of XML 1.0 § 3.2–3.3.4 that real consumers actually rely on:

• Element content models: EMPTY, ANY, Mixed ((#PCDATA | a | b)*), and children models ((a, b), (a | b)+, etc.) with the standard occurrence indicators (?, *, +, none).
• Attribute declarations: every type from § 3.3.1 (CDATA, ID, IDREF, IDREFS, ENTITY, ENTITIES, NMTOKEN, NMTOKENS, NOTATION, enumerated), with all four DefaultDecl flavours (#REQUIRED, #IMPLIED, #FIXED "...", literal default).
• ID uniqueness across the whole document.
• IDREF / IDREFS targets must resolve to an attribute typed ID.

Not yet covered

• Default attribute injection on parse (when an ATTLIST default would supply a missing attribute, our parser ignores it).
• Notation cross-references (NOTATION decls are stored but the set of declared notations is not consulted).
• Parameter-entity-driven declarations inside the external subset.
• Conditional sections (<![INCLUDE[ ... ]]>).

Re-exports

pub use inject::inject_defaults;

pub use inject::inject_defaults_from;

pub use model::AttDecl;

pub use model::AttDefault;

pub use model::AttType;

pub use model::ContentModel;

pub use model::DeclRef;

pub use model::ElementDecl;

pub use model::EntityDecl;

pub use model::Group;

pub use model::GroupKind;

pub use model::Item;

pub use model::Occurrence;

pub use model::Particle;

pub use validate::validate;

pub use validate::DtdError;

Modules

inject

Default attribute injection per XML 1.0 § 3.3.2.

model

Type-level DTD vocabulary — Element/Attribute decls and content models.

validate

DTD validation walk.

Structs

Dtd

Parsed DTD content used by [validate]. Built up incrementally by the bytes-reader as it encounters <!ELEMENT> / <!ATTLIST> declarations in the internal subset.

Functions

collect_id_attrs

Map element local-name → set of ATTLIST-declared ID-type attribute names on that element. Used by id() (XPath 1.0 §4.1) to walk only the DTD-typed attributes; without this map every attribute literally named id is treated as an ID, which catches some real-world cases but misses DTDs that declare an ID attribute under a different name.

collect_idref_attrs

Map element local-name → set of ATTLIST-declared IDREF / IDREFS attribute names on that element. Used by idref() (XPath 2.0 §14.5.5) to locate the attributes that reference a candidate ID.