| // Copyright 2014-2017 The html5ever Project Developers. See the |
| // COPYRIGHT file at the top-level directory of this distribution. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use std::fmt; |
| |
| pub fn to_escaped_string<T: fmt::Debug>(x: &T) -> String { |
| // FIXME: don't allocate twice |
| let string = format!("{:?}", x); |
| string.chars().flat_map(|c| c.escape_default()).collect() |
| } |
| |
| /// If `c` is an ASCII letter, return the corresponding lowercase |
| /// letter, otherwise None. |
| 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 |
| } |
| } |
| |
| /// Is the character an ASCII alphanumeric character? |
| pub fn is_ascii_alnum(c: char) -> bool { |
| matches!(c, '0'...'9' | 'a'...'z' | 'A'...'Z') |
| } |
| |
| /// ASCII whitespace characters, as defined by |
| /// tree construction modes that treat them specially. |
| pub fn is_ascii_whitespace(c: char) -> bool { |
| matches!(c, '\t' | '\r' | '\n' | '\x0C' | ' ') |
| } |
| |
| #[cfg(test)] |
| #[allow(non_snake_case)] |
| mod test { |
| use super::{is_ascii_alnum, lower_ascii_letter}; |
| |
| 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); |
| } |