Mihaela Mihaljevic
c82fef085e
Add PureXML.Parsing.XMLCharacter as the single source of truth for character classes, implementing the exact XML 1.0 (Fifth Edition) Char, NameStartChar, and NameChar productions as public scalar predicates, plus isValidName. The scanner's name recognition now delegates to these exact ranges (replacing a loose isLetter check) and handles precomposed and combining-mark names. Closes #35. Reimplemented from the XML grammar; no upstream code copied. 4 tests; 98 total.
80 lines
2.7 KiB
Swift
80 lines
2.7 KiB
Swift
public extension PureXML.Parsing {
|
|
/// Character classification per the XML 1.0 (Fifth Edition) grammar, the
|
|
/// single source of truth for what bytes are legal where. Predicates operate
|
|
/// on Unicode scalars, since the grammar productions are defined over code
|
|
/// points, not graphemes.
|
|
enum XMLCharacter {
|
|
/// `S`: white space (space, tab, carriage return, line feed).
|
|
public static func isWhitespace(_ scalar: Unicode.Scalar) -> Bool {
|
|
switch scalar.value {
|
|
case 0x20, 0x09, 0x0D, 0x0A: true
|
|
default: false
|
|
}
|
|
}
|
|
|
|
/// `Char`: any legal XML character.
|
|
public static func isChar(_ scalar: Unicode.Scalar) -> Bool {
|
|
switch scalar.value {
|
|
case 0x09, 0x0A, 0x0D,
|
|
0x20 ... 0xD7FF,
|
|
0xE000 ... 0xFFFD,
|
|
0x10000 ... 0x10FFFF:
|
|
true
|
|
default:
|
|
false
|
|
}
|
|
}
|
|
|
|
/// `NameStartChar`: the first character of a name.
|
|
public static func isNameStart(_ scalar: Unicode.Scalar) -> Bool {
|
|
switch scalar.value {
|
|
case 0x3A, // ":"
|
|
0x41 ... 0x5A, // A-Z
|
|
0x5F, // "_"
|
|
0x61 ... 0x7A, // a-z
|
|
0xC0 ... 0xD6,
|
|
0xD8 ... 0xF6,
|
|
0xF8 ... 0x2FF,
|
|
0x370 ... 0x37D,
|
|
0x37F ... 0x1FFF,
|
|
0x200C ... 0x200D,
|
|
0x2070 ... 0x218F,
|
|
0x2C00 ... 0x2FEF,
|
|
0x3001 ... 0xD7FF,
|
|
0xF900 ... 0xFDCF,
|
|
0xFDF0 ... 0xFFFD,
|
|
0x10000 ... 0xEFFFF:
|
|
true
|
|
default:
|
|
false
|
|
}
|
|
}
|
|
|
|
/// `NameChar`: a name character after the first.
|
|
public static func isNameChar(_ scalar: Unicode.Scalar) -> Bool {
|
|
if isNameStart(scalar) { return true }
|
|
switch scalar.value {
|
|
case 0x2D, // "-"
|
|
0x2E, // "."
|
|
0x30 ... 0x39, // 0-9
|
|
0xB7,
|
|
0x300 ... 0x36F,
|
|
0x203F ... 0x2040:
|
|
return true
|
|
default:
|
|
return false
|
|
}
|
|
}
|
|
|
|
/// `Name`: a NameStartChar followed by zero or more NameChar.
|
|
public static func isValidName(_ name: String) -> Bool {
|
|
var scalars = name.unicodeScalars.makeIterator()
|
|
guard let first = scalars.next(), isNameStart(first) else { return false }
|
|
while let scalar = scalars.next() {
|
|
if !isNameChar(scalar) { return false }
|
|
}
|
|
return true
|
|
}
|
|
}
|
|
}
|