grass/src/utils/chars.rs

32 lines
978 B
Rust

pub(crate) fn hex_char_for(number: u32) -> char {
debug_assert!(number < 0x10);
std::char::from_u32(if number < 0xA {
0x30 + number
} else {
0x61 - 0xA + number
})
.unwrap()
}
pub(crate) fn is_name(c: char) -> bool {
is_name_start(c) || c.is_ascii_digit() || c == '-'
}
pub(crate) fn is_name_start(c: char) -> bool {
// NOTE: in the dart-sass implementation, identifiers cannot start
// with numbers. We explicitly differentiate from the reference
// implementation here in order to support selectors beginning with numbers.
// This can be considered a hack and in the future it would be nice to refactor
// how this is handled.
c == '_' || c.is_alphanumeric() || c as u32 >= 0x0080
}
pub(crate) fn as_hex(c: char) -> u32 {
match c {
'0'..='9' => c as u32 - '0' as u32,
'A'..='F' => 10 + c as u32 - 'A' as u32,
'a'..='f' => 10 + c as u32 - 'a' as u32,
_ => panic!(),
}
}