oxml 0.0.4

// SPDX-License-Identifier: MIT OR Apache-2.0
// Copyright (c) 2026 oxml. All rights reserved.

//! Name character classes for XML 1.0 **4th edition**.
//!
//! The 5th edition replaced Appendix B's enumerated character classes
//! with a small set of broad ranges. That is not a superset: the two
//! disagree, and the W3C suite ships complementary pairs proving it —
//! the same name is not-well-formed under editions 1-4 and well-formed
//! under the 5th.
//!
//! A parser that implements only one edition cannot be scored against
//! the other's 309 tests at all, so both are implemented and the
//! caller chooses. The 5th edition is the default, being current.
//!
//! These tables are transcribed from XML 1.0 4th edition Appendix B.
//! Their correctness is not asserted here — it is *measured*, by the
//! 309 conformance tests that exist precisely to distinguish the two
//! editions.

/// `BaseChar`, Appendix B production 85.
const BASE_CHAR: &[(u32, u32)] = &[
    (0x0041, 0x005A),
    (0x0061, 0x007A),
    (0x00C0, 0x00D6),
    (0x00D8, 0x00F6),
    (0x00F8, 0x00FF),
    (0x0100, 0x0131),
    (0x0134, 0x013E),
    (0x0141, 0x0148),
    (0x014A, 0x017E),
    (0x0180, 0x01C3),
    (0x01CD, 0x01F0),
    (0x01F4, 0x01F5),
    (0x01FA, 0x0217),
    (0x0250, 0x02A8),
    (0x02BB, 0x02C1),
    (0x0386, 0x0386),
    (0x0388, 0x038A),
    (0x038C, 0x038C),
    (0x038E, 0x03A1),
    (0x03A3, 0x03CE),
    (0x03D0, 0x03D6),
    (0x03DA, 0x03DA),
    (0x03DC, 0x03DC),
    (0x03DE, 0x03DE),
    (0x03E0, 0x03E0),
    (0x03E2, 0x03F3),
    (0x0401, 0x040C),
    (0x040E, 0x044F),
    (0x0451, 0x045C),
    (0x045E, 0x0481),
    (0x0490, 0x04C4),
    (0x04C7, 0x04C8),
    (0x04CB, 0x04CC),
    (0x04D0, 0x04EB),
    (0x04EE, 0x04F5),
    (0x04F8, 0x04F9),
    (0x0531, 0x0556),
    (0x0559, 0x0559),
    (0x0561, 0x0586),
    (0x05D0, 0x05EA),
    (0x05F0, 0x05F2),
    (0x0621, 0x063A),
    (0x0641, 0x064A),
    (0x0671, 0x06B7),
    (0x06BA, 0x06BE),
    (0x06C0, 0x06CE),
    (0x06D0, 0x06D3),
    (0x06D5, 0x06D5),
    (0x06E5, 0x06E6),
    (0x0905, 0x0939),
    (0x093D, 0x093D),
    (0x0958, 0x0961),
    (0x0985, 0x098C),
    (0x098F, 0x0990),
    (0x0993, 0x09A8),
    (0x09AA, 0x09B0),
    (0x09B2, 0x09B2),
    (0x09B6, 0x09B9),
    (0x09DC, 0x09DD),
    (0x09DF, 0x09E1),
    (0x09F0, 0x09F1),
    (0x0A05, 0x0A0A),
    (0x0A0F, 0x0A10),
    (0x0A13, 0x0A28),
    (0x0A2A, 0x0A30),
    (0x0A32, 0x0A33),
    (0x0A35, 0x0A36),
    (0x0A38, 0x0A39),
    (0x0A59, 0x0A5C),
    (0x0A5E, 0x0A5E),
    (0x0A72, 0x0A74),
    (0x0A85, 0x0A8B),
    (0x0A8D, 0x0A8D),
    (0x0A8F, 0x0A91),
    (0x0A93, 0x0AA8),
    (0x0AAA, 0x0AB0),
    (0x0AB2, 0x0AB3),
    (0x0AB5, 0x0AB9),
    (0x0ABD, 0x0ABD),
    (0x0AE0, 0x0AE0),
    (0x0B05, 0x0B0C),
    (0x0B0F, 0x0B10),
    (0x0B13, 0x0B28),
    (0x0B2A, 0x0B30),
    (0x0B32, 0x0B33),
    (0x0B36, 0x0B39),
    (0x0B3D, 0x0B3D),
    (0x0B5C, 0x0B5D),
    (0x0B5F, 0x0B61),
    (0x0B85, 0x0B8A),
    (0x0B8E, 0x0B90),
    (0x0B92, 0x0B95),
    (0x0B99, 0x0B9A),
    (0x0B9C, 0x0B9C),
    (0x0B9E, 0x0B9F),
    (0x0BA3, 0x0BA4),
    (0x0BA8, 0x0BAA),
    (0x0BAE, 0x0BB5),
    (0x0BB7, 0x0BB9),
    (0x0C05, 0x0C0C),
    (0x0C0E, 0x0C10),
    (0x0C12, 0x0C28),
    (0x0C2A, 0x0C33),
    (0x0C35, 0x0C39),
    (0x0C60, 0x0C61),
    (0x0C85, 0x0C8C),
    (0x0C8E, 0x0C90),
    (0x0C92, 0x0CA8),
    (0x0CAA, 0x0CB3),
    (0x0CB5, 0x0CB9),
    (0x0CDE, 0x0CDE),
    (0x0CE0, 0x0CE1),
    (0x0D05, 0x0D0C),
    (0x0D0E, 0x0D10),
    (0x0D12, 0x0D28),
    (0x0D2A, 0x0D39),
    (0x0D60, 0x0D61),
    (0x0E01, 0x0E2E),
    (0x0E30, 0x0E30),
    (0x0E32, 0x0E33),
    (0x0E40, 0x0E45),
    (0x0E81, 0x0E82),
    (0x0E84, 0x0E84),
    (0x0E87, 0x0E88),
    (0x0E8A, 0x0E8A),
    (0x0E8D, 0x0E8D),
    (0x0E94, 0x0E97),
    (0x0E99, 0x0E9F),
    (0x0EA1, 0x0EA3),
    (0x0EA5, 0x0EA5),
    (0x0EA7, 0x0EA7),
    (0x0EAA, 0x0EAB),
    (0x0EAD, 0x0EAE),
    (0x0EB0, 0x0EB0),
    (0x0EB2, 0x0EB3),
    (0x0EBD, 0x0EBD),
    (0x0EC0, 0x0EC4),
    (0x0F40, 0x0F47),
    (0x0F49, 0x0F69),
    (0x10A0, 0x10C5),
    (0x10D0, 0x10F6),
    (0x1100, 0x1100),
    (0x1102, 0x1103),
    (0x1105, 0x1107),
    (0x1109, 0x1109),
    (0x110B, 0x110C),
    (0x110E, 0x1112),
    (0x113C, 0x113C),
    (0x113E, 0x113E),
    (0x1140, 0x1140),
    (0x114C, 0x114C),
    (0x114E, 0x114E),
    (0x1150, 0x1150),
    (0x1154, 0x1155),
    (0x1159, 0x1159),
    (0x115F, 0x1161),
    (0x1163, 0x1163),
    (0x1165, 0x1165),
    (0x1167, 0x1167),
    (0x1169, 0x1169),
    (0x116D, 0x116E),
    (0x1172, 0x1173),
    (0x1175, 0x1175),
    (0x119E, 0x119E),
    (0x11A8, 0x11A8),
    (0x11AB, 0x11AB),
    (0x11AE, 0x11AF),
    (0x11B7, 0x11B8),
    (0x11BA, 0x11BA),
    (0x11BC, 0x11C2),
    (0x11EB, 0x11EB),
    (0x11F0, 0x11F0),
    (0x11F9, 0x11F9),
    (0x1E00, 0x1E9B),
    (0x1EA0, 0x1EF9),
    (0x1F00, 0x1F15),
    (0x1F18, 0x1F1D),
    (0x1F20, 0x1F45),
    (0x1F48, 0x1F4D),
    (0x1F50, 0x1F57),
    (0x1F59, 0x1F59),
    (0x1F5B, 0x1F5B),
    (0x1F5D, 0x1F5D),
    (0x1F5F, 0x1F7D),
    (0x1F80, 0x1FB4),
    (0x1FB6, 0x1FBC),
    (0x1FBE, 0x1FBE),
    (0x1FC2, 0x1FC4),
    (0x1FC6, 0x1FCC),
    (0x1FD0, 0x1FD3),
    (0x1FD6, 0x1FDB),
    (0x1FE0, 0x1FEC),
    (0x1FF2, 0x1FF4),
    (0x1FF6, 0x1FFC),
    (0x2126, 0x2126),
    (0x212A, 0x212B),
    (0x212E, 0x212E),
    (0x2180, 0x2182),
    (0x3041, 0x3094),
    (0x30A1, 0x30FA),
    (0x3105, 0x312C),
    (0xAC00, 0xD7A3),
];

/// `Ideographic`, Appendix B production 86.
const IDEOGRAPHIC: &[(u32, u32)] =
    &[(0x3007, 0x3007), (0x3021, 0x3029), (0x4E00, 0x9FA5)];

/// `CombiningChar`, Appendix B production 87.
const COMBINING_CHAR: &[(u32, u32)] = &[
    (0x0300, 0x0345),
    (0x0360, 0x0361),
    (0x0483, 0x0486),
    (0x0591, 0x05A1),
    (0x05A3, 0x05B9),
    (0x05BB, 0x05BD),
    (0x05BF, 0x05BF),
    (0x05C1, 0x05C2),
    (0x05C4, 0x05C4),
    (0x064B, 0x0652),
    (0x0670, 0x0670),
    (0x06D6, 0x06DC),
    (0x06DD, 0x06DF),
    (0x06E0, 0x06E4),
    (0x06E7, 0x06E8),
    (0x06EA, 0x06ED),
    (0x0901, 0x0903),
    (0x093C, 0x093C),
    (0x093E, 0x094C),
    (0x094D, 0x094D),
    (0x0951, 0x0954),
    (0x0962, 0x0963),
    (0x0981, 0x0983),
    (0x09BC, 0x09BC),
    (0x09BE, 0x09BE),
    (0x09BF, 0x09BF),
    (0x09C0, 0x09C4),
    (0x09C7, 0x09C8),
    (0x09CB, 0x09CD),
    (0x09D7, 0x09D7),
    (0x09E2, 0x09E3),
    (0x0A02, 0x0A02),
    (0x0A3C, 0x0A3C),
    (0x0A3E, 0x0A3E),
    (0x0A3F, 0x0A3F),
    (0x0A40, 0x0A42),
    (0x0A47, 0x0A48),
    (0x0A4B, 0x0A4D),
    (0x0A70, 0x0A71),
    (0x0A81, 0x0A83),
    (0x0ABC, 0x0ABC),
    (0x0ABE, 0x0AC5),
    (0x0AC7, 0x0AC9),
    (0x0ACB, 0x0ACD),
    (0x0B01, 0x0B03),
    (0x0B3C, 0x0B3C),
    (0x0B3E, 0x0B43),
    (0x0B47, 0x0B48),
    (0x0B4B, 0x0B4D),
    (0x0B56, 0x0B57),
    (0x0B82, 0x0B83),
    (0x0BBE, 0x0BC2),
    (0x0BC6, 0x0BC8),
    (0x0BCA, 0x0BCD),
    (0x0BD7, 0x0BD7),
    (0x0C01, 0x0C03),
    (0x0C3E, 0x0C44),
    (0x0C46, 0x0C48),
    (0x0C4A, 0x0C4D),
    (0x0C55, 0x0C56),
    (0x0C82, 0x0C83),
    (0x0CBE, 0x0CC4),
    (0x0CC6, 0x0CC8),
    (0x0CCA, 0x0CCD),
    (0x0CD5, 0x0CD6),
    (0x0D02, 0x0D03),
    (0x0D3E, 0x0D43),
    (0x0D46, 0x0D48),
    (0x0D4A, 0x0D4D),
    (0x0D57, 0x0D57),
    (0x0E31, 0x0E31),
    (0x0E34, 0x0E3A),
    (0x0E47, 0x0E4E),
    (0x0EB1, 0x0EB1),
    (0x0EB4, 0x0EB9),
    (0x0EBB, 0x0EBC),
    (0x0EC8, 0x0ECD),
    (0x0F18, 0x0F19),
    (0x0F35, 0x0F35),
    (0x0F37, 0x0F37),
    (0x0F39, 0x0F39),
    (0x0F3E, 0x0F3E),
    (0x0F3F, 0x0F3F),
    (0x0F71, 0x0F84),
    (0x0F86, 0x0F8B),
    (0x0F90, 0x0F95),
    (0x0F97, 0x0F97),
    (0x0F99, 0x0FAD),
    (0x0FB1, 0x0FB7),
    (0x0FB9, 0x0FB9),
    (0x20D0, 0x20DC),
    (0x20E1, 0x20E1),
    (0x302A, 0x302F),
    (0x3099, 0x3099),
    (0x309A, 0x309A),
];

/// `Digit`, Appendix B production 88.
const DIGIT: &[(u32, u32)] = &[
    (0x0030, 0x0039),
    (0x0660, 0x0669),
    (0x06F0, 0x06F9),
    (0x0966, 0x096F),
    (0x09E6, 0x09EF),
    (0x0A66, 0x0A6F),
    (0x0AE6, 0x0AEF),
    (0x0B66, 0x0B6F),
    (0x0BE7, 0x0BEF),
    (0x0C66, 0x0C6F),
    (0x0CE6, 0x0CEF),
    (0x0D66, 0x0D6F),
    (0x0E50, 0x0E59),
    (0x0ED0, 0x0ED9),
    (0x0F20, 0x0F29),
];

/// `Extender`, Appendix B production 89.
const EXTENDER: &[(u32, u32)] = &[
    (0x00B7, 0x00B7),
    (0x02D0, 0x02D0),
    (0x02D1, 0x02D1),
    (0x0387, 0x0387),
    (0x0640, 0x0640),
    (0x0E46, 0x0E46),
    (0x0EC6, 0x0EC6),
    (0x3005, 0x3005),
    (0x3031, 0x3035),
    (0x309D, 0x309E),
    (0x30FC, 0x30FE),
];

/// Binary search over a sorted, non-overlapping range table.
fn in_table(table: &[(u32, u32)], c: u32) -> bool {
    table
        .binary_search_by(|&(lo, hi)| {
            if c < lo {
                core::cmp::Ordering::Greater
            } else if c > hi {
                core::cmp::Ordering::Less
            } else {
                core::cmp::Ordering::Equal
            }
        })
        .is_ok()
}

/// `Letter ::= BaseChar | Ideographic`
fn is_letter(c: u32) -> bool {
    in_table(BASE_CHAR, c) || in_table(IDEOGRAPHIC, c)
}

/// `NameStartChar` for XML 1.0 4th edition and earlier.
///
/// Production 5 in those editions begins a name with
/// `Letter | '_' | ':'` — considerably narrower than the 5th edition's
/// broad ranges.
#[must_use]
pub(crate) fn is_name_start_4e(c: char) -> bool {
    let c = c as u32;
    is_letter(c) || c == u32::from(b'_') || c == u32::from(b':')
}

/// `NameChar` for XML 1.0 4th edition and earlier.
#[must_use]
pub(crate) fn is_name_char_4e(c: char) -> bool {
    let n = c as u32;
    is_letter(n)
        || in_table(DIGIT, n)
        || in_table(COMBINING_CHAR, n)
        || in_table(EXTENDER, n)
        || matches!(c, '.' | '-' | '_' | ':')
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn the_tables_are_sorted_and_non_overlapping() {
        // Binary search silently returns wrong answers on an unsorted
        // table, so this is a precondition, not a nicety.
        for (name, t) in [
            ("BASE_CHAR", BASE_CHAR),
            ("IDEOGRAPHIC", IDEOGRAPHIC),
            ("COMBINING_CHAR", COMBINING_CHAR),
            ("DIGIT", DIGIT),
            ("EXTENDER", EXTENDER),
        ] {
            for w in t.windows(2) {
                assert!(
                    w[0].1 < w[1].0,
                    "{name}: {:?} overlaps {:?}",
                    w[0],
                    w[1]
                );
            }
            for &(lo, hi) in t {
                assert!(lo <= hi, "{name}: inverted range ({lo:#X}, {hi:#X})");
            }
        }
    }

    #[test]
    fn ascii_letters_and_digits_behave() {
        assert!(is_name_start_4e('a'));
        assert!(is_name_start_4e('Z'));
        assert!(is_name_start_4e('_'));
        assert!(is_name_start_4e(':'));
        assert!(!is_name_start_4e('0'));
        assert!(!is_name_start_4e('-'));
        assert!(is_name_char_4e('0'));
        assert!(is_name_char_4e('-'));
        assert!(is_name_char_4e('.'));
    }

    #[test]
    fn the_editions_genuinely_disagree() {
        // The whole reason both exist. U+0E5C is legal in a 5th-edition
        // name and not in a 4th-edition one; the suite has a test for
        // exactly this pair.
        let c = char::from_u32(0x0E5C).expect("valid scalar");
        assert!(!is_name_start_4e(c));
        assert!(!is_name_char_4e(c));
    }
}