PureXML/Sources/Parsing/EventReaderEndTag.swift
Mihaela Mihaljevic 9e345ea0fe feat(xpath,parsing): public streaming surface, linear document-order at scale
EventReader.next(), both initializers, and the Event alias are public
(an internal typealias in a split file had been shadowing the public
Parsing.Event); a new PureXMLPublicAPITests target compiles without
testable import so facade gaps fail CI. The large-corpus benchmarks
exposed document-order sorting as quadratic on flat fan-outs; the fix's
first attempt was itself worse (an eager sibling table built per
predicate evaluation), caught by sampling the live run, and replaced
with a lazy table: single-node sets never touch order keys and a
parent's table builds on its second lookup. XPath at 42 MB drops
27.1 s to 1.57 s (190x to 11.7x); at 210 MB PureXML completes in 9.4 s
the query libxml2 refuses at its 10M node-set cap (#143 tracks our
configurable budget). Benchmark harness: size series to 210 MB, CORPUS
mode for real files (NASA, SwissProt measured), SAX stage,
refusal-aware table, NULL-safe C driver. All conformance suites,
Linux, and WASM verified. Closes #142.
2026-06-11 06:06:31 +02:00

29 lines
1.2 KiB
Swift

/// The end-tag scanner, split from the reader body to keep it under the
/// length caps. Behavior is part of EventReader proper.
extension PureXML.Parsing.EventReader {
/// Public: this alias shadows the public Parsing.Event for the whole
/// type, so it must not narrow the public next() signature (#142).
public typealias Event = PureXML.Parsing.Event
typealias ParseError = PureXML.Parsing.ParseError
mutating func scanEndTag() throws -> Event {
let mark = reader.mark
reader.consume("</")
let name = try scanName()
reader.skipSpace()
guard reader.consume(">") else {
throw ParseError.unterminatedTag(reader.mark)
}
guard let top = open.last else {
throw ParseError.unexpectedEndTag(name: name.description, mark)
}
// Tag matching is lexical (the qualified-name text must match); the
// open name additionally carries its resolved namespace URI.
guard top.description == name.description else {
throw ParseError.mismatchedEndTag(expected: top.description, found: name.description, mark)
}
open.removeLast()
namespaces.leaveElement()
return .endElement(name: top)
}
}