src/libstd/str/ascii.rs - third_party/rust - Git at Google

 // Copyright 2013 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.

 use to_str::{ToStr,ToStrConsume};
 use str;
 use str::StrSlice;
 use str::OwnedStr;
 use container::Container;
 use cast;
 use iter::Iterator;
 use vec::{CopyableVector, ImmutableVector, MutableVector};
 use to_bytes::IterBytes;
 use option::{Some, None};

 /// Datatype to hold one ascii character. It wraps a `u8`, with the highest bit always zero.
 #[deriving(Clone, Eq, Ord, TotalOrd, TotalEq)]
 pub struct Ascii { priv chr: u8 }

 impl Ascii {
     /// Converts a ascii character into a `u8`.
     #[inline]
     pub fn to_byte(self) -> u8 {
         self.chr
     }

     /// Converts a ascii character into a `char`.
     #[inline]
     pub fn to_char(self) -> char {
         self.chr as char
     }

     /// Convert to lowercase.
     #[inline]
     pub fn to_lower(self) -> Ascii {
         Ascii{chr: ASCII_LOWER_MAP[self.chr]}
     }

     /// Convert to uppercase.
     #[inline]
     pub fn to_upper(self) -> Ascii {
         Ascii{chr: ASCII_UPPER_MAP[self.chr]}
     }

     /// Compares two ascii characters of equality, ignoring case.
     #[inline]
     pub fn eq_ignore_case(self, other: Ascii) -> bool {
         ASCII_LOWER_MAP[self.chr] == ASCII_LOWER_MAP[other.chr]
     }
 }

 impl ToStr for Ascii {
     #[inline]
     fn to_str(&self) -> ~str {
         // self.chr is always a valid utf8 byte, no need for the check
         unsafe { str::raw::from_byte(self.chr) }
     }
 }

 /// Trait for converting into an ascii type.
 pub trait AsciiCast<T> {
     /// Convert to an ascii type
     fn to_ascii(&self) -> T;

     /// Convert to an ascii type, not doing any range asserts
     unsafe fn to_ascii_nocheck(&self) -> T;

     /// Check if convertible to ascii
     fn is_ascii(&self) -> bool;
 }

 impl<'self> AsciiCast<&'self[Ascii]> for &'self [u8] {
     #[inline]
     fn to_ascii(&self) -> &'self[Ascii] {
         assert!(self.is_ascii());
         unsafe {self.to_ascii_nocheck()}
     }

     #[inline]
     unsafe fn to_ascii_nocheck(&self) -> &'self[Ascii] {
         cast::transmute(*self)
     }

     #[inline]
     fn is_ascii(&self) -> bool {
         for b in self.iter() {
             if !b.is_ascii() { return false; }
         }
         true
     }
 }

 impl<'self> AsciiCast<&'self [Ascii]> for &'self str {
     #[inline]
     fn to_ascii(&self) -> &'self [Ascii] {
         assert!(self.is_ascii());
         unsafe { self.to_ascii_nocheck() }
     }

     #[inline]
     unsafe fn to_ascii_nocheck(&self) -> &'self [Ascii] {
         cast::transmute(*self)
     }

     #[inline]
     fn is_ascii(&self) -> bool {
         self.byte_iter().all(|b| b.is_ascii())
     }
 }

 impl AsciiCast<Ascii> for u8 {
     #[inline]
     fn to_ascii(&self) -> Ascii {
         assert!(self.is_ascii());
         unsafe {self.to_ascii_nocheck()}
     }

     #[inline]
     unsafe fn to_ascii_nocheck(&self) -> Ascii {
         Ascii{ chr: *self }
     }

     #[inline]
     fn is_ascii(&self) -> bool {
         *self & 128 == 0u8
     }
 }

 impl AsciiCast<Ascii> for char {
     #[inline]
     fn to_ascii(&self) -> Ascii {
         assert!(self.is_ascii());
         unsafe {self.to_ascii_nocheck()}
     }

     #[inline]
     unsafe fn to_ascii_nocheck(&self) -> Ascii {
         Ascii{ chr: *self as u8 }
     }

     #[inline]
     fn is_ascii(&self) -> bool {
         *self as u32 - ('\x7F' as u32 & *self as u32) == 0
     }
 }

 /// Trait for copyless casting to an ascii vector.
 pub trait OwnedAsciiCast {
     /// Take ownership and cast to an ascii vector without trailing zero element.
     fn into_ascii(self) -> ~[Ascii];

     /// Take ownership and cast to an ascii vector without trailing zero element.
     /// Does not perform validation checks.
     unsafe fn into_ascii_nocheck(self) -> ~[Ascii];
 }

 impl OwnedAsciiCast for ~[u8] {
     #[inline]
     fn into_ascii(self) -> ~[Ascii] {
         assert!(self.is_ascii());
         unsafe {self.into_ascii_nocheck()}
     }

     #[inline]
     unsafe fn into_ascii_nocheck(self) -> ~[Ascii] {
         cast::transmute(self)
     }
 }

 impl OwnedAsciiCast for ~str {
     #[inline]
     fn into_ascii(self) -> ~[Ascii] {
         assert!(self.is_ascii());
         unsafe {self.into_ascii_nocheck()}
     }

     #[inline]
     unsafe fn into_ascii_nocheck(self) -> ~[Ascii] {
         cast::transmute(self)
     }
 }

 /// Trait for converting an ascii type to a string. Needed to convert `&[Ascii]` to `~str`
 pub trait AsciiStr {
     /// Convert to a string.
     fn to_str_ascii(&self) -> ~str;

     /// Convert to vector representing a lower cased ascii string.
     fn to_lower(&self) -> ~[Ascii];

     /// Convert to vector representing a upper cased ascii string.
     fn to_upper(&self) -> ~[Ascii];

     /// Compares two Ascii strings ignoring case
     fn eq_ignore_case(self, other: &[Ascii]) -> bool;
 }

 impl<'self> AsciiStr for &'self [Ascii] {
     #[inline]
     fn to_str_ascii(&self) -> ~str {
         let cpy = self.to_owned();
         unsafe { cast::transmute(cpy) }
     }

     #[inline]
     fn to_lower(&self) -> ~[Ascii] {
         self.map(|a| a.to_lower())
     }

     #[inline]
     fn to_upper(&self) -> ~[Ascii] {
         self.map(|a| a.to_upper())
     }

     #[inline]
     fn eq_ignore_case(self, other: &[Ascii]) -> bool {
         do self.iter().zip(other.iter()).all |(&a, &b)| { a.eq_ignore_case(b) }
     }
 }

 impl ToStrConsume for ~[Ascii] {
     #[inline]
     fn into_str(self) -> ~str {
         unsafe { cast::transmute(self) }
     }
 }

 impl IterBytes for Ascii {
     #[inline]
     fn iter_bytes(&self, _lsb0: bool, f: &fn(buf: &[u8]) -> bool) -> bool {
         f([self.to_byte()])
     }
 }

 /// Trait to convert to a owned byte array by consuming self
 pub trait ToBytesConsume {
     /// Converts to a owned byte array by consuming self
     fn into_bytes(self) -> ~[u8];
 }

 impl ToBytesConsume for ~[Ascii] {
     fn into_bytes(self) -> ~[u8] {
         unsafe { cast::transmute(self) }
     }
 }

 /// Extension methods for ASCII-subset only operations on owned strings
 pub trait OwnedStrAsciiExt {
     /// Convert 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_upper(self) -> ~str;

     /// Convert 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_lower(self) -> ~str;
 }

 /// Extension methods for ASCII-subset only operations on string slices
 pub trait StrAsciiExt {
     /// 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.
     fn to_ascii_upper(&self) -> ~str;

     /// 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.
     fn to_ascii_lower(&self) -> ~str;

     /// Check that two strings are an ASCII case-insensitive match.
     /// Same as `to_ascii_lower(a) == to_ascii_lower(b)`,
     /// but without allocating and copying temporary strings.
     fn eq_ignore_ascii_case(&self, other: &str) -> bool;
 }

 impl<'self> StrAsciiExt for &'self str {
     #[inline]
     fn to_ascii_upper(&self) -> ~str {
         unsafe { str_copy_map_bytes(*self, ASCII_UPPER_MAP) }
     }

     #[inline]
     fn to_ascii_lower(&self) -> ~str {
         unsafe { str_copy_map_bytes(*self, ASCII_LOWER_MAP) }
     }

     #[inline]
     fn eq_ignore_ascii_case(&self, other: &str) -> bool {
         self.len() == other.len() && self.as_bytes().iter().zip(other.as_bytes().iter()).all(
             |(byte_self, byte_other)| ASCII_LOWER_MAP[*byte_self] == ASCII_LOWER_MAP[*byte_other])
     }
 }

 impl OwnedStrAsciiExt for ~str {
     #[inline]
     fn into_ascii_upper(self) -> ~str {
         unsafe { str_map_bytes(self, ASCII_UPPER_MAP) }
     }

     #[inline]
     fn into_ascii_lower(self) -> ~str {
         unsafe { str_map_bytes(self, ASCII_LOWER_MAP) }
     }
 }

 #[inline]
 unsafe fn str_map_bytes(string: ~str, map: &'static [u8]) -> ~str {
     let mut bytes = string.into_bytes();

     for b in bytes.mut_iter() {
         *b = map[*b];
     }

     str::raw::from_utf8_owned(bytes)
 }

 #[inline]
 unsafe fn str_copy_map_bytes(string: &str, map: &'static [u8]) -> ~str {
     let bytes = string.byte_iter().map(|b| map[b]).to_owned_vec();

     str::raw::from_utf8_owned(bytes)
 }

 static ASCII_LOWER_MAP: &'static [u8] = &[
     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,
     0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
     0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
     0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
     0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
     0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
     0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
     0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
     0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
     0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
     0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
     0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
     0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 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_UPPER_MAP: &'static [u8] = &[
     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,
     0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
     0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
     0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
     0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
     0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
     0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
     0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
     0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
     0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
     0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
     0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
     0x58, 0x59, 0x5a, 0x7b, 0x7c, 0x7d, 0x7e, 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 str::from_char;
     use char::from_u32;

     macro_rules! v2ascii (
         ( [$($e:expr),*]) => ( [$(Ascii{chr:$e}),*]);
         (~[$($e:expr),*]) => (~[$(Ascii{chr:$e}),*]);
     )

     #[test]
     fn test_ascii() {
         assert_eq!(65u8.to_ascii().to_byte(), 65u8);
         assert_eq!(65u8.to_ascii().to_char(), 'A');
         assert_eq!('A'.to_ascii().to_char(), 'A');
         assert_eq!('A'.to_ascii().to_byte(), 65u8);

         assert_eq!('A'.to_ascii().to_lower().to_char(), 'a');
         assert_eq!('Z'.to_ascii().to_lower().to_char(), 'z');
         assert_eq!('a'.to_ascii().to_upper().to_char(), 'A');
         assert_eq!('z'.to_ascii().to_upper().to_char(), 'Z');

         assert_eq!('@'.to_ascii().to_lower().to_char(), '@');
         assert_eq!('['.to_ascii().to_lower().to_char(), '[');
         assert_eq!('`'.to_ascii().to_upper().to_char(), '`');
         assert_eq!('{'.to_ascii().to_upper().to_char(), '{');

         assert!("banana".iter().all(|c| c.is_ascii()));
         assert!(!"ประเทศไทย中华Việt Nam".iter().all(|c| c.is_ascii()));
     }

     #[test]
     fn test_ascii_vec() {
         assert_eq!((&[40u8, 32u8, 59u8]).to_ascii(), v2ascii!([40, 32, 59]));
         assert_eq!("( ;".to_ascii(),                 v2ascii!([40, 32, 59]));
         // FIXME: #5475 borrowchk error, owned vectors do not live long enough
         // if chained-from directly
         let v = ~[40u8, 32u8, 59u8]; assert_eq!(v.to_ascii(), v2ascii!([40, 32, 59]));
         let v = ~"( ;";              assert_eq!(v.to_ascii(), v2ascii!([40, 32, 59]));

         assert_eq!("abCDef&?#".to_ascii().to_lower().to_str_ascii(), ~"abcdef&?#");
         assert_eq!("abCDef&?#".to_ascii().to_upper().to_str_ascii(), ~"ABCDEF&?#");

         assert_eq!("".to_ascii().to_lower().to_str_ascii(), ~"");
         assert_eq!("YMCA".to_ascii().to_lower().to_str_ascii(), ~"ymca");
         assert_eq!("abcDEFxyz:.;".to_ascii().to_upper().to_str_ascii(), ~"ABCDEFXYZ:.;");

         assert!("aBcDeF&?#".to_ascii().eq_ignore_case("AbCdEf&?#".to_ascii()));

         assert!("".is_ascii());
         assert!("a".is_ascii());
         assert!(!"\u2009".is_ascii());

     }

     #[test]
     fn test_owned_ascii_vec() {
         assert_eq!((~"( ;").into_ascii(), v2ascii!(~[40, 32, 59]));
         assert_eq!((~[40u8, 32u8, 59u8]).into_ascii(), v2ascii!(~[40, 32, 59]));
     }

     #[test]
     fn test_ascii_to_str() { assert_eq!(v2ascii!([40, 32, 59]).to_str_ascii(), ~"( ;"); }

     #[test]
     fn test_ascii_into_str() {
         assert_eq!(v2ascii!(~[40, 32, 59]).into_str(), ~"( ;");
     }

     #[test]
     fn test_ascii_to_bytes() {
         assert_eq!(v2ascii!(~[40, 32, 59]).into_bytes(), ~[40u8, 32u8, 59u8]);
     }

     #[test] #[should_fail]
     fn test_ascii_vec_fail_u8_slice()  { (&[127u8, 128u8, 255u8]).to_ascii(); }

     #[test] #[should_fail]
     fn test_ascii_vec_fail_str_slice() { "zoä华".to_ascii(); }

     #[test] #[should_fail]
     fn test_ascii_fail_u8_slice() { 255u8.to_ascii(); }

     #[test] #[should_fail]
     fn test_ascii_fail_char_slice() { 'λ'.to_ascii(); }

     #[test]
     fn test_to_ascii_upper() {
         assert_eq!("url()URL()uRl()ürl".to_ascii_upper(), ~"URL()URL()URL()üRL");
         assert_eq!("hıKß".to_ascii_upper(), ~"HıKß");

         let mut i = 0;
         while i <= 500 {
             let upper = if 'a' as u32 <= i && i <= 'z' as u32 { i + 'A' as u32 - 'a' as u32 }
                         else { i };
             assert_eq!(from_char(from_u32(i).unwrap()).to_ascii_upper(),
                        from_char(from_u32(upper).unwrap()))
             i += 1;
         }
     }

     #[test]
     fn test_to_ascii_lower() {
         assert_eq!("url()URL()uRl()Ürl".to_ascii_lower(), ~"url()url()url()Ürl");
         // Dotted capital I, Kelvin sign, Sharp S.
         assert_eq!("HİKß".to_ascii_lower(), ~"hİKß");

         let mut i = 0;
         while i <= 500 {
             let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 }
                         else { i };
             assert_eq!(from_char(from_u32(i).unwrap()).to_ascii_lower(),
                        from_char(from_u32(lower).unwrap()))
             i += 1;
         }
     }

     #[test]
     fn test_into_ascii_upper() {
         assert_eq!((~"url()URL()uRl()ürl").into_ascii_upper(), ~"URL()URL()URL()üRL");
         assert_eq!((~"hıKß").into_ascii_upper(), ~"HıKß");

         let mut i = 0;
         while i <= 500 {
             let upper = if 'a' as u32 <= i && i <= 'z' as u32 { i + 'A' as u32 - 'a' as u32 }
                         else { i };
             assert_eq!(from_char(from_u32(i).unwrap()).into_ascii_upper(),
                        from_char(from_u32(upper).unwrap()))
             i += 1;
         }
     }

     #[test]
     fn test_into_ascii_lower() {
         assert_eq!((~"url()URL()uRl()Ürl").into_ascii_lower(), ~"url()url()url()Ürl");
         // Dotted capital I, Kelvin sign, Sharp S.
         assert_eq!((~"HİKß").into_ascii_lower(), ~"hİKß");

         let mut i = 0;
         while i <= 500 {
             let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 }
                         else { i };
             assert_eq!(from_char(from_u32(i).unwrap()).into_ascii_lower(),
                        from_char(from_u32(lower).unwrap()))
             i += 1;
         }
     }

     #[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"));

         let mut i = 0;
         while i <= 500 {
             let c = i;
             let lower = if 'A' as u32 <= c && c <= 'Z' as u32 { c + 'a' as u32 - 'A' as u32 }
                         else { c };
             assert!(from_char(from_u32(i).unwrap()).
                 eq_ignore_ascii_case(from_char(from_u32(lower).unwrap())));
             i += 1;
         }
     }

     #[test]
     fn test_to_str() {
         let s = Ascii{ chr: 't' as u8 }.to_str();
         assert_eq!(s, ~"t");
     }


 }
	// Copyright 2013 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.

	use to_str::{ToStr,ToStrConsume};
	use str;
	use str::StrSlice;
	use str::OwnedStr;
	use container::Container;
	use cast;
	use iter::Iterator;
	use vec::{CopyableVector, ImmutableVector, MutableVector};
	use to_bytes::IterBytes;
	use option::{Some, None};

	/// Datatype to hold one ascii character. It wraps a `u8`, with the highest bit always zero.
	#[deriving(Clone, Eq, Ord, TotalOrd, TotalEq)]
	pub struct Ascii { priv chr: u8 }

	impl Ascii {
	/// Converts a ascii character into a `u8`.
	#[inline]
	pub fn to_byte(self) -> u8 {
	self.chr
	}

	/// Converts a ascii character into a `char`.
	#[inline]
	pub fn to_char(self) -> char {
	self.chr as char
	}

	/// Convert to lowercase.
	#[inline]
	pub fn to_lower(self) -> Ascii {
	Ascii{chr: ASCII_LOWER_MAP[self.chr]}
	}

	/// Convert to uppercase.
	#[inline]
	pub fn to_upper(self) -> Ascii {
	Ascii{chr: ASCII_UPPER_MAP[self.chr]}
	}

	/// Compares two ascii characters of equality, ignoring case.
	#[inline]
	pub fn eq_ignore_case(self, other: Ascii) -> bool {
	ASCII_LOWER_MAP[self.chr] == ASCII_LOWER_MAP[other.chr]
	}
	}

	impl ToStr for Ascii {
	#[inline]
	fn to_str(&self) -> ~str {
	// self.chr is always a valid utf8 byte, no need for the check
	unsafe { str::raw::from_byte(self.chr) }
	}
	}

	/// Trait for converting into an ascii type.
	pub trait AsciiCast<T> {
	/// Convert to an ascii type
	fn to_ascii(&self) -> T;

	/// Convert to an ascii type, not doing any range asserts
	unsafe fn to_ascii_nocheck(&self) -> T;

	/// Check if convertible to ascii
	fn is_ascii(&self) -> bool;
	}

	impl<'self> AsciiCast<&'self[Ascii]> for &'self [u8] {
	#[inline]
	fn to_ascii(&self) -> &'self[Ascii] {
	assert!(self.is_ascii());
	unsafe {self.to_ascii_nocheck()}
	}

	#[inline]
	unsafe fn to_ascii_nocheck(&self) -> &'self[Ascii] {
	cast::transmute(*self)
	}

	#[inline]
	fn is_ascii(&self) -> bool {
	for b in self.iter() {
	if !b.is_ascii() { return false; }
	}
	true
	}
	}

	impl<'self> AsciiCast<&'self [Ascii]> for &'self str {
	#[inline]
	fn to_ascii(&self) -> &'self [Ascii] {
	assert!(self.is_ascii());
	unsafe { self.to_ascii_nocheck() }
	}

	#[inline]
	unsafe fn to_ascii_nocheck(&self) -> &'self [Ascii] {
	cast::transmute(*self)
	}

	#[inline]
	fn is_ascii(&self) -> bool {
	self.byte_iter().all(\|b\| b.is_ascii())
	}
	}

	impl AsciiCast<Ascii> for u8 {
	#[inline]
	fn to_ascii(&self) -> Ascii {
	assert!(self.is_ascii());
	unsafe {self.to_ascii_nocheck()}
	}

	#[inline]
	unsafe fn to_ascii_nocheck(&self) -> Ascii {
	Ascii{ chr: *self }
	}

	#[inline]
	fn is_ascii(&self) -> bool {
	*self & 128 == 0u8
	}
	}

	impl AsciiCast<Ascii> for char {
	#[inline]
	fn to_ascii(&self) -> Ascii {
	assert!(self.is_ascii());
	unsafe {self.to_ascii_nocheck()}
	}

	#[inline]
	unsafe fn to_ascii_nocheck(&self) -> Ascii {
	Ascii{ chr: *self as u8 }
	}

	#[inline]
	fn is_ascii(&self) -> bool {
	self as u32 - ('\x7F' as u32 & self as u32) == 0
	}
	}

	/// Trait for copyless casting to an ascii vector.
	pub trait OwnedAsciiCast {
	/// Take ownership and cast to an ascii vector without trailing zero element.
	fn into_ascii(self) -> ~[Ascii];

	/// Take ownership and cast to an ascii vector without trailing zero element.
	/// Does not perform validation checks.
	unsafe fn into_ascii_nocheck(self) -> ~[Ascii];
	}

	impl OwnedAsciiCast for ~[u8] {
	#[inline]
	fn into_ascii(self) -> ~[Ascii] {
	assert!(self.is_ascii());
	unsafe {self.into_ascii_nocheck()}
	}

	#[inline]
	unsafe fn into_ascii_nocheck(self) -> ~[Ascii] {
	cast::transmute(self)
	}
	}

	impl OwnedAsciiCast for ~str {
	#[inline]
	fn into_ascii(self) -> ~[Ascii] {
	assert!(self.is_ascii());
	unsafe {self.into_ascii_nocheck()}
	}

	#[inline]
	unsafe fn into_ascii_nocheck(self) -> ~[Ascii] {
	cast::transmute(self)
	}
	}

	/// Trait for converting an ascii type to a string. Needed to convert `&[Ascii]` to `~str`
	pub trait AsciiStr {
	/// Convert to a string.
	fn to_str_ascii(&self) -> ~str;

	/// Convert to vector representing a lower cased ascii string.
	fn to_lower(&self) -> ~[Ascii];

	/// Convert to vector representing a upper cased ascii string.
	fn to_upper(&self) -> ~[Ascii];

	/// Compares two Ascii strings ignoring case
	fn eq_ignore_case(self, other: &[Ascii]) -> bool;
	}

	impl<'self> AsciiStr for &'self [Ascii] {
	#[inline]
	fn to_str_ascii(&self) -> ~str {
	let cpy = self.to_owned();
	unsafe { cast::transmute(cpy) }
	}

	#[inline]
	fn to_lower(&self) -> ~[Ascii] {
	self.map(\|a\| a.to_lower())
	}

	#[inline]
	fn to_upper(&self) -> ~[Ascii] {
	self.map(\|a\| a.to_upper())
	}

	#[inline]
	fn eq_ignore_case(self, other: &[Ascii]) -> bool {
	do self.iter().zip(other.iter()).all \|(&a, &b)\| { a.eq_ignore_case(b) }
	}
	}

	impl ToStrConsume for ~[Ascii] {
	#[inline]
	fn into_str(self) -> ~str {
	unsafe { cast::transmute(self) }
	}
	}

	impl IterBytes for Ascii {
	#[inline]
	fn iter_bytes(&self, _lsb0: bool, f: &fn(buf: &[u8]) -> bool) -> bool {
	f([self.to_byte()])
	}
	}

	/// Trait to convert to a owned byte array by consuming self
	pub trait ToBytesConsume {
	/// Converts to a owned byte array by consuming self
	fn into_bytes(self) -> ~[u8];
	}

	impl ToBytesConsume for ~[Ascii] {
	fn into_bytes(self) -> ~[u8] {
	unsafe { cast::transmute(self) }
	}
	}

	/// Extension methods for ASCII-subset only operations on owned strings
	pub trait OwnedStrAsciiExt {
	/// Convert 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_upper(self) -> ~str;

	/// Convert 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_lower(self) -> ~str;
	}

	/// Extension methods for ASCII-subset only operations on string slices
	pub trait StrAsciiExt {
	/// 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.
	fn to_ascii_upper(&self) -> ~str;

	/// 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.
	fn to_ascii_lower(&self) -> ~str;

	/// Check that two strings are an ASCII case-insensitive match.
	/// Same as `to_ascii_lower(a) == to_ascii_lower(b)`,
	/// but without allocating and copying temporary strings.
	fn eq_ignore_ascii_case(&self, other: &str) -> bool;
	}

	impl<'self> StrAsciiExt for &'self str {
	#[inline]
	fn to_ascii_upper(&self) -> ~str {
	unsafe { str_copy_map_bytes(*self, ASCII_UPPER_MAP) }
	}

	#[inline]
	fn to_ascii_lower(&self) -> ~str {
	unsafe { str_copy_map_bytes(*self, ASCII_LOWER_MAP) }
	}

	#[inline]
	fn eq_ignore_ascii_case(&self, other: &str) -> bool {
	self.len() == other.len() && self.as_bytes().iter().zip(other.as_bytes().iter()).all(
	\|(byte_self, byte_other)\| ASCII_LOWER_MAP[byte_self] == ASCII_LOWER_MAP[byte_other])
	}
	}

	impl OwnedStrAsciiExt for ~str {
	#[inline]
	fn into_ascii_upper(self) -> ~str {
	unsafe { str_map_bytes(self, ASCII_UPPER_MAP) }
	}

	#[inline]
	fn into_ascii_lower(self) -> ~str {
	unsafe { str_map_bytes(self, ASCII_LOWER_MAP) }
	}
	}

	#[inline]
	unsafe fn str_map_bytes(string: ~str, map: &'static [u8]) -> ~str {
	let mut bytes = string.into_bytes();

	for b in bytes.mut_iter() {
	b = map[b];
	}

	str::raw::from_utf8_owned(bytes)
	}

	#[inline]
	unsafe fn str_copy_map_bytes(string: &str, map: &'static [u8]) -> ~str {
	let bytes = string.byte_iter().map(\|b\| map[b]).to_owned_vec();

	str::raw::from_utf8_owned(bytes)
	}

	static ASCII_LOWER_MAP: &'static [u8] = &[
	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,
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
	0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
	0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
	0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 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_UPPER_MAP: &'static [u8] = &[
	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,
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
	0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
	0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
	0x58, 0x59, 0x5a, 0x7b, 0x7c, 0x7d, 0x7e, 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 str::from_char;
	use char::from_u32;

	macro_rules! v2ascii (
	( [$($e:expr),]) => ( [$(Ascii{chr:$e}),]);
	(~[$($e:expr),]) => (~[$(Ascii{chr:$e}),]);
	)

	#[test]
	fn test_ascii() {
	assert_eq!(65u8.to_ascii().to_byte(), 65u8);
	assert_eq!(65u8.to_ascii().to_char(), 'A');
	assert_eq!('A'.to_ascii().to_char(), 'A');
	assert_eq!('A'.to_ascii().to_byte(), 65u8);

	assert_eq!('A'.to_ascii().to_lower().to_char(), 'a');
	assert_eq!('Z'.to_ascii().to_lower().to_char(), 'z');
	assert_eq!('a'.to_ascii().to_upper().to_char(), 'A');
	assert_eq!('z'.to_ascii().to_upper().to_char(), 'Z');

	assert_eq!('@'.to_ascii().to_lower().to_char(), '@');
	assert_eq!('['.to_ascii().to_lower().to_char(), '[');
	assert_eq!('`'.to_ascii().to_upper().to_char(), '`');
	assert_eq!('{'.to_ascii().to_upper().to_char(), '{');

	assert!("banana".iter().all(\|c\| c.is_ascii()));
	assert!(!"ประเทศไทย中华Việt Nam".iter().all(\|c\| c.is_ascii()));
	}

	#[test]
	fn test_ascii_vec() {
	assert_eq!((&[40u8, 32u8, 59u8]).to_ascii(), v2ascii!([40, 32, 59]));
	assert_eq!("( ;".to_ascii(), v2ascii!([40, 32, 59]));
	// FIXME: #5475 borrowchk error, owned vectors do not live long enough
	// if chained-from directly
	let v = ~[40u8, 32u8, 59u8]; assert_eq!(v.to_ascii(), v2ascii!([40, 32, 59]));
	let v = ~"( ;"; assert_eq!(v.to_ascii(), v2ascii!([40, 32, 59]));

	assert_eq!("abCDef&?#".to_ascii().to_lower().to_str_ascii(), ~"abcdef&?#");
	assert_eq!("abCDef&?#".to_ascii().to_upper().to_str_ascii(), ~"ABCDEF&?#");

	assert_eq!("".to_ascii().to_lower().to_str_ascii(), ~"");
	assert_eq!("YMCA".to_ascii().to_lower().to_str_ascii(), ~"ymca");
	assert_eq!("abcDEFxyz:.;".to_ascii().to_upper().to_str_ascii(), ~"ABCDEFXYZ:.;");

	assert!("aBcDeF&?#".to_ascii().eq_ignore_case("AbCdEf&?#".to_ascii()));

	assert!("".is_ascii());
	assert!("a".is_ascii());
	assert!(!"\u2009".is_ascii());

	}

	#[test]
	fn test_owned_ascii_vec() {
	assert_eq!((~"( ;").into_ascii(), v2ascii!(~[40, 32, 59]));
	assert_eq!((~[40u8, 32u8, 59u8]).into_ascii(), v2ascii!(~[40, 32, 59]));
	}

	#[test]
	fn test_ascii_to_str() { assert_eq!(v2ascii!([40, 32, 59]).to_str_ascii(), ~"( ;"); }

	#[test]
	fn test_ascii_into_str() {
	assert_eq!(v2ascii!(~[40, 32, 59]).into_str(), ~"( ;");
	}

	#[test]
	fn test_ascii_to_bytes() {
	assert_eq!(v2ascii!(~[40, 32, 59]).into_bytes(), ~[40u8, 32u8, 59u8]);
	}

	#[test] #[should_fail]
	fn test_ascii_vec_fail_u8_slice() { (&[127u8, 128u8, 255u8]).to_ascii(); }

	#[test] #[should_fail]
	fn test_ascii_vec_fail_str_slice() { "zoä华".to_ascii(); }

	#[test] #[should_fail]
	fn test_ascii_fail_u8_slice() { 255u8.to_ascii(); }

	#[test] #[should_fail]
	fn test_ascii_fail_char_slice() { 'λ'.to_ascii(); }

	#[test]
	fn test_to_ascii_upper() {
	assert_eq!("url()URL()uRl()ürl".to_ascii_upper(), ~"URL()URL()URL()üRL");
	assert_eq!("hıKß".to_ascii_upper(), ~"HıKß");

	let mut i = 0;
	while i <= 500 {
	let upper = if 'a' as u32 <= i && i <= 'z' as u32 { i + 'A' as u32 - 'a' as u32 }
	else { i };
	assert_eq!(from_char(from_u32(i).unwrap()).to_ascii_upper(),
	from_char(from_u32(upper).unwrap()))
	i += 1;
	}
	}

	#[test]
	fn test_to_ascii_lower() {
	assert_eq!("url()URL()uRl()Ürl".to_ascii_lower(), ~"url()url()url()Ürl");
	// Dotted capital I, Kelvin sign, Sharp S.
	assert_eq!("HİKß".to_ascii_lower(), ~"hİKß");

	let mut i = 0;
	while i <= 500 {
	let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 }
	else { i };
	assert_eq!(from_char(from_u32(i).unwrap()).to_ascii_lower(),
	from_char(from_u32(lower).unwrap()))
	i += 1;
	}
	}

	#[test]
	fn test_into_ascii_upper() {
	assert_eq!((~"url()URL()uRl()ürl").into_ascii_upper(), ~"URL()URL()URL()üRL");
	assert_eq!((~"hıKß").into_ascii_upper(), ~"HıKß");

	let mut i = 0;
	while i <= 500 {
	let upper = if 'a' as u32 <= i && i <= 'z' as u32 { i + 'A' as u32 - 'a' as u32 }
	else { i };
	assert_eq!(from_char(from_u32(i).unwrap()).into_ascii_upper(),
	from_char(from_u32(upper).unwrap()))
	i += 1;
	}
	}

	#[test]
	fn test_into_ascii_lower() {
	assert_eq!((~"url()URL()uRl()Ürl").into_ascii_lower(), ~"url()url()url()Ürl");
	// Dotted capital I, Kelvin sign, Sharp S.
	assert_eq!((~"HİKß").into_ascii_lower(), ~"hİKß");

	let mut i = 0;
	while i <= 500 {
	let lower = if 'A' as u32 <= i && i <= 'Z' as u32 { i + 'a' as u32 - 'A' as u32 }
	else { i };
	assert_eq!(from_char(from_u32(i).unwrap()).into_ascii_lower(),
	from_char(from_u32(lower).unwrap()))
	i += 1;
	}
	}

	#[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"));

	let mut i = 0;
	while i <= 500 {
	let c = i;
	let lower = if 'A' as u32 <= c && c <= 'Z' as u32 { c + 'a' as u32 - 'A' as u32 }
	else { c };
	assert!(from_char(from_u32(i).unwrap()).
	eq_ignore_ascii_case(from_char(from_u32(lower).unwrap())));
	i += 1;
	}
	}

	#[test]
	fn test_to_str() {
	let s = Ascii{ chr: 't' as u8 }.to_str();
	assert_eq!(s, ~"t");
	}


	}