rust/src/libstd/ascii.rs
2015-06-17 09:06:59 -07:00

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// 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 <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.
//! Operations on ASCII strings and characters
#![stable(feature = "rust1", since = "1.0.0")]
use prelude::v1::*;
use ops::Range;
use mem;
/// Extension methods for ASCII-subset only operations on owned strings
#[unstable(feature = "owned_ascii_ext",
reason = "would prefer to do this in a more general way")]
pub trait OwnedAsciiExt {
/// Converts the string to ASCII upper case:
/// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z',
/// but non-ASCII letters are unchanged.
fn into_ascii_uppercase(self) -> Self;
/// Converts the string to ASCII lower case:
/// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z',
/// but non-ASCII letters are unchanged.
fn into_ascii_lowercase(self) -> Self;
}
/// Extension methods for ASCII-subset only operations on string slices.
#[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 within the ASCII range.
///
/// # Examples
///
/// ```
/// use std::ascii::AsciiExt;
///
/// let ascii = 'a';
/// let utf8 = '❤';
///
/// assert_eq!(true, ascii.is_ascii());
/// assert_eq!(false, 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_eq!(true, ascii1.eq_ignore_ascii_case(&ascii2));
/// assert_eq!(true, ascii1.eq_ignore_ascii_case(&ascii3));
/// assert_eq!(false, 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
///
/// ```
/// # #![feature(ascii)]
/// use std::ascii::AsciiExt;
///
/// let mut ascii = 'a';
///
/// ascii.make_ascii_uppercase();
///
/// assert_eq!('A', ascii);
/// ```
#[unstable(feature = "ascii")]
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
///
/// ```
/// # #![feature(ascii)]
/// use std::ascii::AsciiExt;
///
/// let mut ascii = 'A';
///
/// ascii.make_ascii_lowercase();
///
/// assert_eq!('a', ascii);
/// ```
#[unstable(feature = "ascii")]
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 {
self.to_string().into_ascii_uppercase()
}
#[inline]
fn to_ascii_lowercase(&self) -> String {
self.to_string().into_ascii_lowercase()
}
#[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()
}
}
impl OwnedAsciiExt for String {
#[inline]
fn into_ascii_uppercase(self) -> String {
// Vec<u8>::into_ascii_uppercase() preserves the UTF-8 invariant.
unsafe { String::from_utf8_unchecked(self.into_bytes().into_ascii_uppercase()) }
}
#[inline]
fn into_ascii_lowercase(self) -> String {
// Vec<u8>::into_ascii_lowercase() preserves the UTF-8 invariant.
unsafe { String::from_utf8_unchecked(self.into_bytes().into_ascii_lowercase()) }
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl AsciiExt for [u8] {
type Owned = Vec<u8>;
#[inline]
fn is_ascii(&self) -> bool {
self.iter().all(|b| b.is_ascii())
}
#[inline]
fn to_ascii_uppercase(&self) -> Vec<u8> {
self.to_vec().into_ascii_uppercase()
}
#[inline]
fn to_ascii_lowercase(&self) -> Vec<u8> {
self.to_vec().into_ascii_lowercase()
}
#[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();
}
}
}
impl OwnedAsciiExt for Vec<u8> {
#[inline]
fn into_ascii_uppercase(mut self) -> Vec<u8> {
self.make_ascii_uppercase();
self
}
#[inline]
fn into_ascii_lowercase(mut self) -> Vec<u8> {
self.make_ascii_lowercase();
self
}
}
#[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<usize>,
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<u8> { self.range.next().map(|i| self.data[i]) }
fn size_hint(&self) -> (usize, Option<usize>) { self.range.size_hint() }
}
#[stable(feature = "rust1", since = "1.0.0")]
impl DoubleEndedIterator for EscapeDefault {
fn next_back(&mut self) -> Option<u8> {
self.range.next_back().map(|i| self.data[i])
}
}
#[stable(feature = "rust1", since = "1.0.0")]
impl ExactSizeIterator 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 prelude::v1::*;
use super::*;
use char::from_u32;
#[test]
fn test_ascii() {
assert!("banana".chars().all(|c| c.is_ascii()));
assert!(!"ประเทศไทย中华Việt Nam".chars().all(|c| c.is_ascii()));
}
#[test]
fn test_ascii_vec() {
assert!("".is_ascii());
assert!("a".is_ascii());
assert!(!"\u{2009}".is_ascii());
}
#[test]
fn test_to_ascii_uppercase() {
assert_eq!("url()URL()uRl()ürl".to_ascii_uppercase(), "URL()URL()URL()üRL");
assert_eq!("hıß".to_ascii_uppercase(), "Hıß");
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!("ß".to_ascii_lowercase(), "ß");
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_into_ascii_uppercase() {
assert_eq!(("url()URL()uRl()ürl".to_string()).into_ascii_uppercase(),
"URL()URL()URL()üRL".to_string());
assert_eq!(("hıß".to_string()).into_ascii_uppercase(), "Hıß");
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().into_ascii_uppercase(),
(from_u32(upper).unwrap()).to_string());
}
}
#[test]
fn test_into_ascii_lowercase() {
assert_eq!(("url()URL()uRl()Ürl".to_string()).into_ascii_lowercase(),
"url()url()url()Ürl");
// Dotted capital I, Kelvin sign, Sharp S.
assert_eq!(("ß".to_string()).into_ascii_lowercase(), "ß");
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().into_ascii_lowercase(),
(from_u32(lower).unwrap()).to_string());
}
}
#[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!("ß".eq_ignore_ascii_case("ß"));
assert!(!"İ".eq_ignore_ascii_case("i"));
assert!(!"".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()));
}
}
}