Broaden the TextReader pull cursor toward libxml2's xmlTextReader:
- Attribute nodes: moveToFirstAttribute/moveToNextAttribute/
moveToAttribute(_:)/moveToElement reposition the cursor onto each
attribute as an .attribute node and back.
- Namespace accessors: namespaceURI, localName, prefix from the current
element's or attribute's resolved name.
- xml:lang: inherited down the tree, overridable per element, reset when
it goes out of scope.
- Position: lineNumber/columnNumber report where each node begins, so a
streaming consumer can locate findings in the source. EventReader now
records each node's start mark.
DOCTYPE and entity-reference nodes are not surfaced (the DTD is exposed
through documentType, and entities are expanded inline); whitespace is
not split into significant/insignificant (needs the content model);
baseURI needs a document URI. The accurate positioning path for editor
findings remains readTree with source ranges.
Closes#98
Parse the XML declaration's pseudo-attributes instead of skipping the
<?xml?> processing instruction:
- version, encoding, and standalone are surfaced on a new XMLDeclaration,
returned from parseWithDocumentType and via PureXML.xmlDeclaration(_:).
- The pseudo-attributes are validated: fixed order (version, encoding,
standalone), known names only, and standalone must be yes or no. A
malformed declaration is rejected.
- The declared version is now readable, a prerequisite for XML 1.1.
parseWithDocumentType returns a ParsedDocument struct (node,
documentType, declaration) rather than a 2-tuple; the member names are
unchanged so existing call sites are unaffected.
Closes#95
Slice 1 of #94 (editor integration). The keystone: a located validation finding
can now be mapped back to a source range.
- TreeNode gains a sourceRange (start/end Mark); SourceRange is a half-open span.
- PureXML.readTree builds a mutable, parent-aware, best-effort tree whose every
node carries its span (an element from the < of its start tag to past its end
tag; leaves over the text they consumed). Never throws, recovers in place,
returns located diagnostics.
- TreeNode.node(at:) navigates a validation coding path to its node using the
same canonical convention the validators build paths with (a sibling index
only when a name repeats), and sourceRange(at:) returns the span. So
Document.validate's ValidationError.codingPath resolves to characters in the
document.
Tests prove the spans, the navigation, the end-to-end bridge (an XSD finding to
a source range), and that ranged reading of invalid input never crashes.
Closes#93. Recovery moves into a recovering mode on EventReader, so malformed
input is repaired in place rather than dropped to the next markup boundary:
- A duplicate attribute is recorded and the later occurrence dropped, keeping the
element. <a id='1' id='2'>y</a> now reads as <a id="1">y</a> with one
diagnostic (was an empty tree with three).
- A mismatched or unexpected end tag pops the open stack to the matching ancestor,
implicitly closing the elements nested inside it. <a><b><c>x</b></a> reads as
<a><b><c>x</c></b></a> with a single diagnostic.
- Pre-root junk reports "unexpected character" instead of the misleading
"content after the root element".
In recovering mode next() no longer throws: it records a Diagnostic and emits
best-effort events, popping to a match on a mismatch and stopping on truncation
so the builder closes what is open. The strict path is unchanged. readRecovering
becomes a plain non-throwing drain that takes the reader's diagnostics. Recovery
stays deterministic; new tests pin the kept-element and pop-to-match results.
Slice 2 of #92. Add PureXML.read, a deterministic recovering reader: it never
throws and never traps, returning the maximal best-effort tree plus one located
Diagnostic per problem.
- ReadResult { node, diagnostics } is the Equatable result type, so a
deterministic read can be compared whole.
- Diagnostic carries a message and a structured source Mark; a thrown ParseError
maps to one directly (ParseError.mark exposes the position each case carries).
- The reader resynchronizes after a failure (EventReader.recover(from:)):
progress-aware, so a failure that already consumed the bad construct retries
from there, while a stuck failure skips to the next markup start; it always
advances when input remains, guaranteeing termination.
- The tree builder assembles leniently: elements left open by truncation are
closed, an end tag with no open element is dropped. Well-formed input yields
exactly parse(_:)'s tree with no diagnostics.
Tests pin exact trees and diagnostics for truncation, mismatched tags, and stray
junk, prove determinism (same bytes give an identical ReadResult), and fuzz 400
seeded inputs (arbitrary plus truncated valid docs) asserting no crash.
Recovery here is resync-based; finer in-reader recovery (keep the element on a
duplicate attribute, pop to a matching open tag) is the next slice.
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.
