Mihaela Mihaljevic
4e5debd557
Add a resumable XML scanner that reports a token only once its terminator is fully buffered and otherwise signals need-more (the Expat XML_TOK_PARTIAL model), and PushParser with feed(_:)/finish() driving a SAXHandler while retaining only the current incomplete token plus the open-element stack. events(feeding:) exposes an AsyncThrowingStream of events over any async sequence of text chunks. Splitting a document at any byte boundary, down to one character per feed, yields identical events. Collapse the completed roadmap into the legend summary. Closes #4 Closes #5 Closes #6 Closes #7 Closes #1
40 lines
1.7 KiB
Swift
40 lines
1.7 KiB
Swift
public extension PureXML {
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/// Parses an asynchronous sequence of text chunks (a socket, a file read loop)
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/// into a stream of ``Parsing/Event`` values, driving the push parser as each
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/// chunk arrives. The document is never held whole.
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@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
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static func events<Chunks: AsyncSequence & Sendable>(
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feeding chunks: Chunks,
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) -> AsyncThrowingStream<Parsing.Event, Error> where Chunks.Element == String {
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AsyncThrowingStream { continuation in
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let task = Task {
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do {
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var parser = Parsing.PushParser(sax: Self.streamingHandler(continuation))
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for try await chunk in chunks {
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try parser.feed(chunk)
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}
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try parser.finish()
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continuation.finish()
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} catch {
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continuation.finish(throwing: error)
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}
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}
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continuation.onTermination = { _ in task.cancel() }
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}
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}
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@available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)
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private static func streamingHandler(
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_ continuation: AsyncThrowingStream<Parsing.Event, Error>.Continuation,
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) -> Parsing.SAXHandler {
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Parsing.SAXHandler(
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startElement: { continuation.yield(.startElement(name: $0, attributes: $1)) },
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endElement: { continuation.yield(.endElement(name: $0)) },
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characters: { continuation.yield(.characters($0)) },
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cdata: { continuation.yield(.cdata($0)) },
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comment: { continuation.yield(.comment($0)) },
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processingInstruction: { continuation.yield(.processingInstruction(target: $0, data: $1)) },
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)
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}
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}
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