Mihaela Mihaljevic
cfba3ed7d2
Add the PureXML.HTML namespace: a lenient tokenizer for tag-soup input (case-insensitive tags; quoted, unquoted, and boolean attributes; comments; doctype; character references), a tree builder handling void elements, optional end tags (li, p, table rows and cells), raw-text elements (script, style), and unmatched end tags, and a serializer that writes void elements unclosed and raw-text content unescaped. Closes #36 Closes #37 Closes #38 Closes #39 Closes #20
55 lines
2.1 KiB
Swift
55 lines
2.1 KiB
Swift
extension PureXML.HTML.Tokenizer {
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private static let named: [String: Character] = [
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"amp": "&", "lt": "<", "gt": ">", "quot": "\"", "apos": "'",
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"nbsp": "\u{A0}", "copy": "\u{A9}", "reg": "\u{AE}", "trade": "\u{2122}",
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"mdash": "\u{2014}", "ndash": "\u{2013}", "hellip": "\u{2026}",
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"laquo": "\u{AB}", "raquo": "\u{BB}", "deg": "\u{B0}", "euro": "\u{20AC}",
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]
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/// Decodes the common HTML character references in `value`, leaving any
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/// unrecognized `&...;` sequence as written (the lenient HTML behavior).
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static func decodeEntities(_ value: String) -> String {
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guard value.contains("&") else { return value }
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var result = ""
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var characters = Array(value)
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var index = 0
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while index < characters.count {
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guard characters[index] == "&", let semicolon = nextSemicolon(characters, after: index) else {
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result.append(characters[index])
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index += 1
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continue
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}
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let body = String(characters[(index + 1) ..< semicolon])
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if let decoded = decode(body) {
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result.append(decoded)
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index = semicolon + 1
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} else {
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result.append("&")
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index += 1
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}
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}
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return result
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}
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private static func nextSemicolon(_ characters: [Character], after start: Int) -> Int? {
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var index = start + 1
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while index < characters.count, index - start <= 10 {
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if characters[index] == ";" { return index }
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index += 1
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}
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return nil
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}
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private static func decode(_ body: String) -> Character? {
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if let named = named[body] { return named }
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guard body.hasPrefix("#") else { return nil }
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let digits = body.dropFirst()
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let scalar: UInt32? = if digits.hasPrefix("x") || digits.hasPrefix("X") {
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UInt32(digits.dropFirst(), radix: 16)
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} else {
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UInt32(digits, radix: 10)
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}
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return scalar.flatMap(Unicode.Scalar.init).map(Character.init)
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}
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}
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