Add internal parameter entities (parsed, stored, and expanded within the
DTD, including bare %name; references that inject markup declarations,
bounded by depth and the expansion budget). Record external general
entities and the external subset identifier, and load them only through an
injected EntityResolver (a struct of closures). The default refusing
resolver fetches nothing, so XXE stays closed: an external entity fails as
undefined and the external subset is left unread. Internal declarations win
over the external subset.
Closes#29
Surface <!ATTLIST> declarations from the parser and validate attributes against
them. Reimplemented from the DTD attribute-list spec; no upstream code copied.
- DocumentType gains attributeLists (raw ATTLIST bodies per element); the
DoctypeScanner captures them and the EventReader plumbs them through.
- AttributeListParser parses a body into AttributeDeclaration values
(AttributeType: cdata or enumeration; AttributeDefault: required/implied/
fixed/value).
- DTDSchema now checks #REQUIRED presence, #FIXED value match (when present),
and enumerated-value membership, in addition to content models.
- Tokenized types (ID/IDREF/NMTOKEN) parse but are not yet value-enforced.
- 5 attribute tests; 75 total.
Surface the parsed <!DOCTYPE> internal subset's <!ELEMENT> declarations from the
parser and validate a tree against them. Reimplemented from the DTD content-model
spec; no upstream code copied.
- DoctypeScanner captures <!ELEMENT name model> declarations; the parser surfaces
them as Parsing.DocumentType (via parseWithDocumentType).
- Validation.ContentModel + ContentModelParser parse a model string (EMPTY, ANY,
(#PCDATA), mixed, and element content with sequence/choice and ?/*/+).
- ContentModelMatcher matches the child element-name sequence against a model as
a regular language (NFA-position matching).
- Validation.DTDSchema.validate reports issues for EMPTY/PCDATA/mixed violations,
element content with stray text, and child sequences that do not match.
- PureXML.validateAgainstInternalDTD(_:) parses and validates in one call.
- ATTLIST validation is out of scope. 9 tests; 70 total.
Add opt-in DTD processing behind Limits(allowDoctype:), off by default. When on,
DoctypeScanner reads the <!DOCTYPE> internal subset and honors internal
<!ENTITY name "value"> general entities, which EntityDecoder expands recursively
in text and attribute values.
Safety is mandatory and reimplemented from the Expat amplification-accounting
model (no upstream code copied):
- only entity-expanded characters count against a shared budget
(Limits.maxEntityExpansion); overflow raises amplificationLimitExceeded, which
defeats billion-laughs.
- a visiting set detects recursive entities (recursiveEntity).
- undeclared references raise undefinedEntity.
- external entities are never stored or loaded, so XXE stays closed.
The default still rejects <!DOCTYPE>. 8 DTD tests (incl. billion-laughs and the
external-entity refusal); 49 total.
Add namespace resolution following the XML Namespaces rules, reimplemented in
Swift from libxml2's SAX2 model; no upstream code copied.
- QualifiedName gains an optional resolved namespaceURI (nil for names built
directly or in no namespace), with a resolved(namespaceURI:) helper.
- NamespaceContext maintains a scope stack of xmlns bindings as elements open
and close, resolving element and attribute names against it.
- A default namespace applies to unprefixed element names but never to
attributes; the xml prefix is built in; xmlns declarations are preserved as
attributes so documents round-trip; an unbound prefix raises
ParseError.undefinedNamespacePrefix. End-tag matching stays lexical.
- Namespace-free documents are unchanged (URIs remain nil).
- 7 namespace tests; 39 total.
Add PureXML.Parsing.Limits: configurable caps on nesting depth (default 256,
matching libxml2), name length, and content length, enforced during scanning in
the event reader. This protects against pathological input (deeply nested or
oversized documents) and keeps the recursive Model.Node value safe to build and
tear down (extreme depth otherwise overflows on ARC release). Threaded through
Parser.parse and the top-level parse/events API. Reimplemented from libxml2's
bounded-by-default posture; no upstream code copied.
Replace the notImplemented stub with a real parser built on a pull-based,
streaming event core that never requires the whole document in memory.
- Parsing.EventReader: pulls characters through a source closure with a bounded
lookahead buffer and emits one Parsing.Event at a time, holding only an
open-element stack. Drives chunked/streamed input.
- Parsing.Parser: builds a Model.Node tree iteratively over the event core
(explicit stack, no recursion).
- Reader: streaming character cursor (closure-backed, bounded buffer) replacing
the previous whole-string Array.
- EntityDecoder: the five predefined entities and decimal/hex char references.
- Handles elements, attributes, text, comments, CDATA, processing instructions,
and an XML declaration in the prolog. Rejects <!DOCTYPE> by default (no
DTD/XXE/entity-expansion exposure).
- Top-level API: parse(_:), parse(pulling:), events(_:), events(pulling:).
- 21 tests including event-stream and chunked-source coverage.
