speedy-xml 0.1.1

pub const RAPIDXML_WHITESPACE: &[u8] = b" \n\r\t";
// NOTE: ':' is additionally treated as unsupported.
//       This is to implement prefixed names, and is not how RapidXML works.
pub const RAPIDXML_INVALID_NAME: &[u8] = b" \n\r\t/>?\0:";
pub const RAPIDXML_INVALID_ATTRNAME: &[u8] = b" \n\r\t/<>=?!\0:";

const fn make_big_lut(values: &[u8]) -> [bool; 256] {
    let mut result = [false; 256];

    let mut i = 0;
    while i < values.len() {
        result[values[i] as usize] = true;
        i += 1;
    }

    result
}

pub fn is_whitespace(chr: u8) -> bool {
    const LUT: [bool; 256] = make_big_lut(RAPIDXML_WHITESPACE);
    LUT[chr as usize]
}

pub fn is_invalid_name(chr: u8) -> bool {
    const LUT: [bool; 256] = make_big_lut(RAPIDXML_INVALID_NAME);
    LUT[chr as usize]
}

pub fn is_invalid_attribute_name(chr: u8) -> bool {
    const LUT: [bool; 256] = make_big_lut(RAPIDXML_INVALID_ATTRNAME);
    LUT[chr as usize]
}

#[cfg(test)]
mod test {
    fn test_lut_fn(truthy: &[u8], fun: impl Fn(u8) -> bool) {
        for chr in 0..u8::MAX {
            assert_eq!(fun(chr), truthy.contains(&chr))
        }
    }

    #[test]
    fn is_whitespace() {
        test_lut_fn(super::RAPIDXML_WHITESPACE, super::is_whitespace);
    }

    #[test]
    fn is_invalid_element_name() {
        test_lut_fn(super::RAPIDXML_INVALID_NAME, super::is_invalid_name);
    }

    #[test]
    fn is_invalid_attribute_name() {
        test_lut_fn(
            super::RAPIDXML_INVALID_ATTRNAME,
            super::is_invalid_attribute_name,
        );
    }
}