use std::{fmt, u32};
use mac::{_tt_as_expr_hack, matches};
pub fn to_escaped_string<T: fmt::Debug>(x: &T) -> String {
let string = format!("{:?}", x);
string.chars().flat_map(|c| c.escape_default()).collect()
}
pub fn lower_ascii_letter(c: char) -> Option<char> {
match c {
'a'..='z' => Some(c),
'A'..='Z' => Some((c as u8 - b'A' + b'a') as char),
_ => None,
}
}
pub fn is_ascii_alnum(c: char) -> bool {
matches!(c, '0'..='9' | 'a'..='z' | 'A'..='Z')
}
pub fn is_ascii_whitespace(c: char) -> bool {
matches!(c, '\t' | '\r' | '\n' | '\x0C' | ' ')
}
pub const MARK: &str = "yartehashhtmlexpressionsattt";
const MARK_LEN: usize = MARK.len();
const S: &str = "0x";
const S_LEN: usize = S.len();
pub const HASH_LEN: usize = 10;
pub fn is_mark(s: &str) -> bool {
s.len() == MARK_LEN + HASH_LEN && &s[..MARK_LEN] == MARK && parse_id(&s[MARK_LEN..]).is_some()
}
pub fn parse_id(s: &str) -> Option<u32> {
if &s[..S_LEN] == S && s[S_LEN..].chars().all(|x| x.is_ascii_hexdigit()) {
u32::from_str_radix(&s[S_LEN..], 16).ok()
} else {
None
}
}
pub fn get_mark_id(s: &str) -> Option<u32> {
if is_mark(s) {
u32::from_str_radix(&s[MARK_LEN + S_LEN..], 16).ok()
} else {
None
}
}
#[cfg(test)]
#[allow(non_snake_case)]
mod test {
use super::{is_ascii_alnum, lower_ascii_letter};
use mac::test_eq;
test_eq!(lower_letter_a_is_a, lower_ascii_letter('a'), Some('a'));
test_eq!(lower_letter_A_is_a, lower_ascii_letter('A'), Some('a'));
test_eq!(lower_letter_symbol_is_None, lower_ascii_letter('!'), None);
test_eq!(
lower_letter_nonascii_is_None,
lower_ascii_letter('\u{a66e}'),
None
);
test_eq!(is_alnum_a, is_ascii_alnum('a'), true);
test_eq!(is_alnum_A, is_ascii_alnum('A'), true);
test_eq!(is_alnum_1, is_ascii_alnum('1'), true);
test_eq!(is_not_alnum_symbol, is_ascii_alnum('!'), false);
test_eq!(is_not_alnum_nonascii, is_ascii_alnum('\u{a66e}'), false);
}