Mihaela Mihaljevic
f7fe89023c
Add the PureXML.Pattern namespace: a compiler for the streamable XPath subset (names, *, prefix:*, /, //, leading absolute /, trailing @attr) into a Matcher, with predicates and . / .. rejected. The backward-matching algorithm tests an element's ancestor-or-self path. Pattern.matches(_:in:) streams a document through the pull parser and returns matching node paths in document order from the open-element stack alone, no tree built. Closes #44 Closes #45 Closes #22
19 lines
668 B
Swift
19 lines
668 B
Swift
public extension PureXML.Pattern {
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/// An error compiling a streaming pattern.
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enum PatternError: Swift.Error, Equatable, Sendable, CustomStringConvertible {
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case empty
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case expectedStep
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/// A construct outside the streamable subset (a predicate, an attribute
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/// step that is not last, or `.`/`..`).
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case unsupported(String)
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public var description: String {
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switch self {
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case .empty: "the pattern is empty"
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case .expectedStep: "expected a step after '/'"
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case let .unsupported(detail): "unsupported pattern construct: \(detail)"
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}
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}
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}
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}
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