// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! Operations on ASCII strings and characters. #![stable(feature = "rust1", since = "1.0.0")] use mem; use ops::Range; use iter::FusedIterator; /// Extension methods for ASCII-subset only operations on string slices. /// /// Be aware that operations on seemingly non-ASCII characters can sometimes /// have unexpected results. Consider this example: /// /// ``` /// use std::ascii::AsciiExt; /// /// assert_eq!("café".to_ascii_uppercase(), "CAFÉ"); /// assert_eq!("café".to_ascii_uppercase(), "CAFé"); /// ``` /// /// In the first example, the lowercased string is represented `"cafe\u{301}"` /// (the last character is an acute accent [combining character]). Unlike the /// other characters in the string, the combining character will not get mapped /// to an uppercase variant, resulting in `"CAFE\u{301}"`. In the second /// example, the lowercased string is represented `"caf\u{e9}"` (the last /// character is a single Unicode character representing an 'e' with an acute /// accent). Since the last character is defined outside the scope of ASCII, /// it will not get mapped to an uppercase variant, resulting in `"CAF\u{e9}"`. /// /// [combining character]: https://en.wikipedia.org/wiki/Combining_character #[stable(feature = "rust1", since = "1.0.0")] pub trait AsciiExt { /// Container type for copied ASCII characters. #[stable(feature = "rust1", since = "1.0.0")] type Owned; /// Checks if the value is within the ASCII range. /// /// # Examples /// /// ``` /// use std::ascii::AsciiExt; /// /// let ascii = 'a'; /// let utf8 = '❤'; /// /// assert!(ascii.is_ascii()); /// assert!(!utf8.is_ascii()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] fn is_ascii(&self) -> bool; /// Makes a copy of the string in ASCII upper case. /// /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', /// but non-ASCII letters are unchanged. /// /// # Examples /// /// ``` /// use std::ascii::AsciiExt; /// /// let ascii = 'a'; /// let utf8 = '❤'; /// /// assert_eq!('A', ascii.to_ascii_uppercase()); /// assert_eq!('❤', utf8.to_ascii_uppercase()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] fn to_ascii_uppercase(&self) -> Self::Owned; /// Makes a copy of the string in ASCII lower case. /// /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', /// but non-ASCII letters are unchanged. /// /// # Examples /// /// ``` /// use std::ascii::AsciiExt; /// /// let ascii = 'A'; /// let utf8 = '❤'; /// /// assert_eq!('a', ascii.to_ascii_lowercase()); /// assert_eq!('❤', utf8.to_ascii_lowercase()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] fn to_ascii_lowercase(&self) -> Self::Owned; /// Checks that two strings are an ASCII case-insensitive match. /// /// Same as `to_ascii_lowercase(a) == to_ascii_lowercase(b)`, /// but without allocating and copying temporary strings. /// /// # Examples /// /// ``` /// use std::ascii::AsciiExt; /// /// let ascii1 = 'A'; /// let ascii2 = 'a'; /// let ascii3 = 'A'; /// let ascii4 = 'z'; /// /// assert!(ascii1.eq_ignore_ascii_case(&ascii2)); /// assert!(ascii1.eq_ignore_ascii_case(&ascii3)); /// assert!(!ascii1.eq_ignore_ascii_case(&ascii4)); /// ``` #[stable(feature = "rust1", since = "1.0.0")] fn eq_ignore_ascii_case(&self, other: &Self) -> bool; /// Converts this type to its ASCII upper case equivalent in-place. /// /// See `to_ascii_uppercase` for more information. /// /// # Examples /// /// ``` /// use std::ascii::AsciiExt; /// /// let mut ascii = 'a'; /// /// ascii.make_ascii_uppercase(); /// /// assert_eq!('A', ascii); /// ``` #[stable(feature = "ascii", since = "1.9.0")] fn make_ascii_uppercase(&mut self); /// Converts this type to its ASCII lower case equivalent in-place. /// /// See `to_ascii_lowercase` for more information. /// /// # Examples /// /// ``` /// use std::ascii::AsciiExt; /// /// let mut ascii = 'A'; /// /// ascii.make_ascii_lowercase(); /// /// assert_eq!('a', ascii); /// ``` #[stable(feature = "ascii", since = "1.9.0")] fn make_ascii_lowercase(&mut self); } #[stable(feature = "rust1", since = "1.0.0")] impl AsciiExt for str { type Owned = String; #[inline] fn is_ascii(&self) -> bool { self.bytes().all(|b| b.is_ascii()) } #[inline] fn to_ascii_uppercase(&self) -> String { let mut bytes = self.as_bytes().to_vec(); bytes.make_ascii_uppercase(); // make_ascii_uppercase() preserves the UTF-8 invariant. unsafe { String::from_utf8_unchecked(bytes) } } #[inline] fn to_ascii_lowercase(&self) -> String { let mut bytes = self.as_bytes().to_vec(); bytes.make_ascii_lowercase(); // make_ascii_uppercase() preserves the UTF-8 invariant. unsafe { String::from_utf8_unchecked(bytes) } } #[inline] fn eq_ignore_ascii_case(&self, other: &str) -> bool { self.as_bytes().eq_ignore_ascii_case(other.as_bytes()) } fn make_ascii_uppercase(&mut self) { let me: &mut [u8] = unsafe { mem::transmute(self) }; me.make_ascii_uppercase() } fn make_ascii_lowercase(&mut self) { let me: &mut [u8] = unsafe { mem::transmute(self) }; me.make_ascii_lowercase() } } #[stable(feature = "rust1", since = "1.0.0")] impl AsciiExt for [u8] { type Owned = Vec; #[inline] fn is_ascii(&self) -> bool { self.iter().all(|b| b.is_ascii()) } #[inline] fn to_ascii_uppercase(&self) -> Vec { let mut me = self.to_vec(); me.make_ascii_uppercase(); return me } #[inline] fn to_ascii_lowercase(&self) -> Vec { let mut me = self.to_vec(); me.make_ascii_lowercase(); return me } #[inline] fn eq_ignore_ascii_case(&self, other: &[u8]) -> bool { self.len() == other.len() && self.iter().zip(other).all(|(a, b)| { a.eq_ignore_ascii_case(b) }) } fn make_ascii_uppercase(&mut self) { for byte in self { byte.make_ascii_uppercase(); } } fn make_ascii_lowercase(&mut self) { for byte in self { byte.make_ascii_lowercase(); } } } #[stable(feature = "rust1", since = "1.0.0")] impl AsciiExt for u8 { type Owned = u8; #[inline] fn is_ascii(&self) -> bool { *self & 128 == 0 } #[inline] fn to_ascii_uppercase(&self) -> u8 { ASCII_UPPERCASE_MAP[*self as usize] } #[inline] fn to_ascii_lowercase(&self) -> u8 { ASCII_LOWERCASE_MAP[*self as usize] } #[inline] fn eq_ignore_ascii_case(&self, other: &u8) -> bool { self.to_ascii_lowercase() == other.to_ascii_lowercase() } #[inline] fn make_ascii_uppercase(&mut self) { *self = self.to_ascii_uppercase(); } #[inline] fn make_ascii_lowercase(&mut self) { *self = self.to_ascii_lowercase(); } } #[stable(feature = "rust1", since = "1.0.0")] impl AsciiExt for char { type Owned = char; #[inline] fn is_ascii(&self) -> bool { *self as u32 <= 0x7F } #[inline] fn to_ascii_uppercase(&self) -> char { if self.is_ascii() { (*self as u8).to_ascii_uppercase() as char } else { *self } } #[inline] fn to_ascii_lowercase(&self) -> char { if self.is_ascii() { (*self as u8).to_ascii_lowercase() as char } else { *self } } #[inline] fn eq_ignore_ascii_case(&self, other: &char) -> bool { self.to_ascii_lowercase() == other.to_ascii_lowercase() } #[inline] fn make_ascii_uppercase(&mut self) { *self = self.to_ascii_uppercase(); } #[inline] fn make_ascii_lowercase(&mut self) { *self = self.to_ascii_lowercase(); } } /// An iterator over the escaped version of a byte, constructed via /// `std::ascii::escape_default`. #[stable(feature = "rust1", since = "1.0.0")] pub struct EscapeDefault { range: Range, data: [u8; 4], } /// Returns an iterator that produces an escaped version of a `u8`. /// /// The default is chosen with a bias toward producing literals that are /// legal in a variety of languages, including C++11 and similar C-family /// languages. The exact rules are: /// /// - Tab, CR and LF are escaped as '\t', '\r' and '\n' respectively. /// - Single-quote, double-quote and backslash chars are backslash-escaped. /// - Any other chars in the range [0x20,0x7e] are not escaped. /// - Any other chars are given hex escapes of the form '\xNN'. /// - Unicode escapes are never generated by this function. /// /// # Examples /// /// ``` /// use std::ascii; /// /// let escaped = ascii::escape_default(b'0').next().unwrap(); /// assert_eq!(b'0', escaped); /// /// let mut escaped = ascii::escape_default(b'\t'); /// /// assert_eq!(b'\\', escaped.next().unwrap()); /// assert_eq!(b't', escaped.next().unwrap()); /// ``` #[stable(feature = "rust1", since = "1.0.0")] pub fn escape_default(c: u8) -> EscapeDefault { let (data, len) = match c { b'\t' => ([b'\\', b't', 0, 0], 2), b'\r' => ([b'\\', b'r', 0, 0], 2), b'\n' => ([b'\\', b'n', 0, 0], 2), b'\\' => ([b'\\', b'\\', 0, 0], 2), b'\'' => ([b'\\', b'\'', 0, 0], 2), b'"' => ([b'\\', b'"', 0, 0], 2), b'\x20' ... b'\x7e' => ([c, 0, 0, 0], 1), _ => ([b'\\', b'x', hexify(c >> 4), hexify(c & 0xf)], 4), }; return EscapeDefault { range: (0.. len), data: data }; fn hexify(b: u8) -> u8 { match b { 0 ... 9 => b'0' + b, _ => b'a' + b - 10, } } } #[stable(feature = "rust1", since = "1.0.0")] impl Iterator for EscapeDefault { type Item = u8; fn next(&mut self) -> Option { self.range.next().map(|i| self.data[i]) } fn size_hint(&self) -> (usize, Option) { self.range.size_hint() } } #[stable(feature = "rust1", since = "1.0.0")] impl DoubleEndedIterator for EscapeDefault { fn next_back(&mut self) -> Option { self.range.next_back().map(|i| self.data[i]) } } #[stable(feature = "rust1", since = "1.0.0")] impl ExactSizeIterator for EscapeDefault {} #[unstable(feature = "fused", issue = "35602")] impl FusedIterator for EscapeDefault {} static ASCII_LOWERCASE_MAP: [u8; 256] = [ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, b' ', b'!', b'"', b'#', b'$', b'%', b'&', b'\'', b'(', b')', b'*', b'+', b',', b'-', b'.', b'/', b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b':', b';', b'<', b'=', b'>', b'?', b'@', b'a', b'b', b'c', b'd', b'e', b'f', b'g', b'h', b'i', b'j', b'k', b'l', b'm', b'n', b'o', b'p', b'q', b'r', b's', b't', b'u', b'v', b'w', b'x', b'y', b'z', b'[', b'\\', b']', b'^', b'_', b'`', b'a', b'b', b'c', b'd', b'e', b'f', b'g', b'h', b'i', b'j', b'k', b'l', b'm', b'n', b'o', b'p', b'q', b'r', b's', b't', b'u', b'v', b'w', b'x', b'y', b'z', b'{', b'|', b'}', b'~', 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, ]; static ASCII_UPPERCASE_MAP: [u8; 256] = [ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, b' ', b'!', b'"', b'#', b'$', b'%', b'&', b'\'', b'(', b')', b'*', b'+', b',', b'-', b'.', b'/', b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b':', b';', b'<', b'=', b'>', b'?', b'@', b'A', b'B', b'C', b'D', b'E', b'F', b'G', b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O', b'P', b'Q', b'R', b'S', b'T', b'U', b'V', b'W', b'X', b'Y', b'Z', b'[', b'\\', b']', b'^', b'_', b'`', b'A', b'B', b'C', b'D', b'E', b'F', b'G', b'H', b'I', b'J', b'K', b'L', b'M', b'N', b'O', b'P', b'Q', b'R', b'S', b'T', b'U', b'V', b'W', b'X', b'Y', b'Z', b'{', b'|', b'}', b'~', 0x7f, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, ]; #[cfg(test)] mod tests { use super::*; use char::from_u32; #[test] fn test_is_ascii() { assert!(b"".is_ascii()); assert!(b"banana\0\x7F".is_ascii()); assert!(b"banana\0\x7F".iter().all(|b| b.is_ascii())); assert!(!b"Vi\xe1\xbb\x87t Nam".is_ascii()); assert!(!b"Vi\xe1\xbb\x87t Nam".iter().all(|b| b.is_ascii())); assert!(!b"\xe1\xbb\x87".iter().any(|b| b.is_ascii())); assert!("".is_ascii()); assert!("banana\0\u{7F}".is_ascii()); assert!("banana\0\u{7F}".chars().all(|c| c.is_ascii())); assert!(!"ประเทศไทย中华Việt Nam".chars().all(|c| c.is_ascii())); assert!(!"ประเทศไทย中华ệ ".chars().any(|c| c.is_ascii())); } #[test] fn test_to_ascii_uppercase() { assert_eq!("url()URL()uRl()ürl".to_ascii_uppercase(), "URL()URL()URL()üRL"); assert_eq!("hıKß".to_ascii_uppercase(), "HıKß"); for i in 0..501 { let upper = if 'a' as u32 <= i && i <= 'z' as u32 { i + 'A' as u32 - 'a' as u32 } else { i }; assert_eq!((from_u32(i).unwrap()).to_string().to_ascii_uppercase(), (from_u32(upper).unwrap()).to_string()); } } #[test] fn test_to_ascii_lowercase() { assert_eq!("url()URL()uRl()Ürl".to_ascii_lowercase(), "url()url()url()Ürl"); // Dotted capital I, Kelvin sign, Sharp S. assert_eq!("HİKß".to_ascii_lowercase(), "hİKß"); for i in 0..501 { let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 } else { i }; assert_eq!((from_u32(i).unwrap()).to_string().to_ascii_lowercase(), (from_u32(lower).unwrap()).to_string()); } } #[test] fn test_make_ascii_lower_case() { macro_rules! test { ($from: expr, $to: expr) => { { let mut x = $from; x.make_ascii_lowercase(); assert_eq!(x, $to); } } } test!(b'A', b'a'); test!(b'a', b'a'); test!(b'!', b'!'); test!('A', 'a'); test!('À', 'À'); test!('a', 'a'); test!('!', '!'); test!(b"H\xc3\x89".to_vec(), b"h\xc3\x89"); test!("HİKß".to_string(), "hİKß"); } #[test] fn test_make_ascii_upper_case() { macro_rules! test { ($from: expr, $to: expr) => { { let mut x = $from; x.make_ascii_uppercase(); assert_eq!(x, $to); } } } test!(b'a', b'A'); test!(b'A', b'A'); test!(b'!', b'!'); test!('a', 'A'); test!('à', 'à'); test!('A', 'A'); test!('!', '!'); test!(b"h\xc3\xa9".to_vec(), b"H\xc3\xa9"); test!("hıKß".to_string(), "HıKß"); let mut x = "Hello".to_string(); x[..3].make_ascii_uppercase(); // Test IndexMut on String. assert_eq!(x, "HELlo") } #[test] fn test_eq_ignore_ascii_case() { assert!("url()URL()uRl()Ürl".eq_ignore_ascii_case("url()url()url()Ürl")); assert!(!"Ürl".eq_ignore_ascii_case("ürl")); // Dotted capital I, Kelvin sign, Sharp S. assert!("HİKß".eq_ignore_ascii_case("hİKß")); assert!(!"İ".eq_ignore_ascii_case("i")); assert!(!"K".eq_ignore_ascii_case("k")); assert!(!"ß".eq_ignore_ascii_case("s")); for i in 0..501 { let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 } else { i }; assert!((from_u32(i).unwrap()).to_string().eq_ignore_ascii_case( &from_u32(lower).unwrap().to_string())); } } #[test] fn inference_works() { let x = "a".to_string(); x.eq_ignore_ascii_case("A"); } }