core: Inherit the char module

2 files changed, 1 insertions, 846 deletions

diff --git a/src/libstd/char.rs b/src/libstd/char.rs
deleted file mode 100644
index 228db221cfc..00000000000
--- a/src/libstd/char.rs
+++ /dev/null
@@ -1,845 +0,0 @@
-// Copyright 2012-2013 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.
-
-//! Character manipulation (`char` type, Unicode Scalar Value)
-//!
-//! This module  provides the `Char` trait, as well as its implementation
-//! for the primitive `char` type, in order to allow basic character manipulation.
-//!
-//! A `char` actually represents a
-//! *[Unicode Scalar Value](http://www.unicode.org/glossary/#unicode_scalar_value)*,
-//! as it can contain any Unicode code point except high-surrogate and
-//! low-surrogate code points.
-//!
-//! As such, only values in the ranges \[0x0,0xD7FF\] and \[0xE000,0x10FFFF\]
-//! (inclusive) are allowed. A `char` can always be safely cast to a `u32`;
-//! however the converse is not always true due to the above range limits
-//! and, as such, should be performed via the `from_u32` function..
-
-
-use cast::transmute;
-use option::{None, Option, Some};
-use iter::{Iterator, range_step};
-use str::StrSlice;
-use unicode::{derived_property, property, general_category, decompose, conversions};
-
-#[cfg(test)] use str::Str;
-#[cfg(test)] use strbuf::StrBuf;
-#[cfg(test)] use slice::ImmutableVector;
-
-#[cfg(not(test))] use cmp::{Eq, Ord};
-#[cfg(not(test))] use default::Default;
-
-// UTF-8 ranges and tags for encoding characters
-static TAG_CONT: uint = 128u;
-static MAX_ONE_B: uint = 128u;
-static TAG_TWO_B: uint = 192u;
-static MAX_TWO_B: uint = 2048u;
-static TAG_THREE_B: uint = 224u;
-static MAX_THREE_B: uint = 65536u;
-static TAG_FOUR_B: uint = 240u;
-
-/*
-    Lu  Uppercase_Letter        an uppercase letter
-    Ll  Lowercase_Letter        a lowercase letter
-    Lt  Titlecase_Letter        a digraphic character, with first part uppercase
-    Lm  Modifier_Letter         a modifier letter
-    Lo  Other_Letter            other letters, including syllables and ideographs
-    Mn  Nonspacing_Mark         a nonspacing combining mark (zero advance width)
-    Mc  Spacing_Mark            a spacing combining mark (positive advance width)
-    Me  Enclosing_Mark          an enclosing combining mark
-    Nd  Decimal_Number          a decimal digit
-    Nl  Letter_Number           a letterlike numeric character
-    No  Other_Number            a numeric character of other type
-    Pc  Connector_Punctuation   a connecting punctuation mark, like a tie
-    Pd  Dash_Punctuation        a dash or hyphen punctuation mark
-    Ps  Open_Punctuation        an opening punctuation mark (of a pair)
-    Pe  Close_Punctuation       a closing punctuation mark (of a pair)
-    Pi  Initial_Punctuation     an initial quotation mark
-    Pf  Final_Punctuation       a final quotation mark
-    Po  Other_Punctuation       a punctuation mark of other type
-    Sm  Math_Symbol             a symbol of primarily mathematical use
-    Sc  Currency_Symbol         a currency sign
-    Sk  Modifier_Symbol         a non-letterlike modifier symbol
-    So  Other_Symbol            a symbol of other type
-    Zs  Space_Separator         a space character (of various non-zero widths)
-    Zl  Line_Separator          U+2028 LINE SEPARATOR only
-    Zp  Paragraph_Separator     U+2029 PARAGRAPH SEPARATOR only
-    Cc  Control                 a C0 or C1 control code
-    Cf  Format                  a format control character
-    Cs  Surrogate               a surrogate code point
-    Co  Private_Use             a private-use character
-    Cn  Unassigned              a reserved unassigned code point or a noncharacter
-*/
-
-/// The highest valid code point
-pub static MAX: char = '\U0010ffff';
-
-/// Converts from `u32` to a `char`
-#[inline]
-pub fn from_u32(i: u32) -> Option<char> {
-    // catch out-of-bounds and surrogates
-    if (i > MAX as u32) || (i >= 0xD800 && i <= 0xDFFF) {
-        None
-    } else {
-        Some(unsafe { transmute(i) })
-    }
-}
-
-/// Returns whether the specified `char` is considered a Unicode alphabetic
-/// code point
-pub fn is_alphabetic(c: char) -> bool   { derived_property::Alphabetic(c) }
-
-/// Returns whether the specified `char` satisfies the 'XID_Start' Unicode property
-///
-/// 'XID_Start' is a Unicode Derived Property specified in
-/// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
-/// mostly similar to ID_Start but modified for closure under NFKx.
-pub fn is_XID_start(c: char) -> bool    { derived_property::XID_Start(c) }
-
-/// Returns whether the specified `char` satisfies the 'XID_Continue' Unicode property
-///
-/// 'XID_Continue' is a Unicode Derived Property specified in
-/// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
-/// mostly similar to 'ID_Continue' but modified for closure under NFKx.
-pub fn is_XID_continue(c: char) -> bool { derived_property::XID_Continue(c) }
-
-///
-/// Indicates whether a `char` is in lower case
-///
-/// This is defined according to the terms of the Unicode Derived Core Property 'Lowercase'.
-///
-#[inline]
-pub fn is_lowercase(c: char) -> bool { derived_property::Lowercase(c) }
-
-///
-/// Indicates whether a `char` is in upper case
-///
-/// This is defined according to the terms of the Unicode Derived Core Property 'Uppercase'.
-///
-#[inline]
-pub fn is_uppercase(c: char) -> bool { derived_property::Uppercase(c) }
-
-///
-/// Indicates whether a `char` is whitespace
-///
-/// Whitespace is defined in terms of the Unicode Property 'White_Space'.
-///
-#[inline]
-pub fn is_whitespace(c: char) -> bool {
-    // As an optimization ASCII whitespace characters are checked separately
-    c == ' '
-        || ('\x09' <= c && c <= '\x0d')
-        || property::White_Space(c)
-}
-
-///
-/// Indicates whether a `char` is alphanumeric
-///
-/// Alphanumericness is defined in terms of the Unicode General Categories
-/// 'Nd', 'Nl', 'No' and the Derived Core Property 'Alphabetic'.
-///
-#[inline]
-pub fn is_alphanumeric(c: char) -> bool {
-    derived_property::Alphabetic(c)
-        || general_category::Nd(c)
-        || general_category::Nl(c)
-        || general_category::No(c)
-}
-
-///
-/// Indicates whether a `char` is a control code point
-///
-/// Control code points are defined in terms of the Unicode General Category
-/// 'Cc'.
-///
-#[inline]
-pub fn is_control(c: char) -> bool { general_category::Cc(c) }
-
-/// Indicates whether the `char` is numeric (Nd, Nl, or No)
-#[inline]
-pub fn is_digit(c: char) -> bool {
-    general_category::Nd(c)
-        || general_category::Nl(c)
-        || general_category::No(c)
-}
-
-///
-/// Checks if a `char` parses as a numeric digit in the given radix
-///
-/// Compared to `is_digit()`, this function only recognizes the
-/// characters `0-9`, `a-z` and `A-Z`.
-///
-/// # Return value
-///
-/// Returns `true` if `c` is a valid digit under `radix`, and `false`
-/// otherwise.
-///
-/// # Failure
-///
-/// Fails if given a `radix` > 36.
-///
-/// # Note
-///
-/// This just wraps `to_digit()`.
-///
-#[inline]
-pub fn is_digit_radix(c: char, radix: uint) -> bool {
-    match to_digit(c, radix) {
-        Some(_) => true,
-        None    => false,
-    }
-}
-
-///
-/// Converts a `char` to the corresponding digit
-///
-/// # Return value
-///
-/// If `c` is between '0' and '9', the corresponding value
-/// between 0 and 9. If `c` is 'a' or 'A', 10. If `c` is
-/// 'b' or 'B', 11, etc. Returns none if the `char` does not
-/// refer to a digit in the given radix.
-///
-/// # Failure
-///
-/// Fails if given a `radix` outside the range `[0..36]`.
-///
-#[inline]
-pub fn to_digit(c: char, radix: uint) -> Option<uint> {
-    if radix > 36 {
-        fail!("to_digit: radix {} is too high (maximum 36)", radix);
-    }
-    let val = match c {
-      '0' .. '9' => c as uint - ('0' as uint),
-      'a' .. 'z' => c as uint + 10u - ('a' as uint),
-      'A' .. 'Z' => c as uint + 10u - ('A' as uint),
-      _ => return None,
-    };
-    if val < radix { Some(val) }
-    else { None }
-}
-
-/// Convert a char to its uppercase equivalent
-///
-/// The case-folding performed is the common or simple mapping:
-/// it maps one unicode codepoint (one char in Rust) to its uppercase equivalent according
-/// to the Unicode database at ftp://ftp.unicode.org/Public/UNIDATA/UnicodeData.txt
-/// The additional SpecialCasing.txt is not considered here, as it expands to multiple
-/// codepoints in some cases.
-///
-/// A full reference can be found here
-/// http://www.unicode.org/versions/Unicode4.0.0/ch03.pdf#G33992
-///
-/// # Return value
-///
-/// Returns the char itself if no conversion was made
-#[inline]
-pub fn to_uppercase(c: char) -> char {
-    conversions::to_upper(c)
-}
-
-/// Convert a char to its lowercase equivalent
-///
-/// The case-folding performed is the common or simple mapping
-/// see `to_uppercase` for references and more information
-///
-/// # Return value
-///
-/// Returns the char itself if no conversion if possible
-#[inline]
-pub fn to_lowercase(c: char) -> char {
-    conversions::to_lower(c)
-}
-
-///
-/// Converts a number to the character representing it
-///
-/// # Return value
-///
-/// Returns `Some(char)` if `num` represents one digit under `radix`,
-/// using one character of `0-9` or `a-z`, or `None` if it doesn't.
-///
-/// # Failure
-///
-/// Fails if given an `radix` > 36.
-///
-#[inline]
-pub fn from_digit(num: uint, radix: uint) -> Option<char> {
-    if radix > 36 {
-        fail!("from_digit: radix {} is to high (maximum 36)", num);
-    }
-    if num < radix {
-        unsafe {
-            if num < 10 {
-                Some(transmute(('0' as uint + num) as u32))
-            } else {
-                Some(transmute(('a' as uint + num - 10u) as u32))
-            }
-        }
-    } else {
-        None
-    }
-}
-
-// Constants from Unicode 6.2.0 Section 3.12 Conjoining Jamo Behavior
-static S_BASE: uint = 0xAC00;
-static L_BASE: uint = 0x1100;
-static V_BASE: uint = 0x1161;
-static T_BASE: uint = 0x11A7;
-static L_COUNT: uint = 19;
-static V_COUNT: uint = 21;
-static T_COUNT: uint = 28;
-static N_COUNT: uint = (V_COUNT * T_COUNT);
-static S_COUNT: uint = (L_COUNT * N_COUNT);
-
-// Decompose a precomposed Hangul syllable
-fn decompose_hangul(s: char, f: |char|) {
-    let si = s as uint - S_BASE;
-
-    let li = si / N_COUNT;
-    unsafe {
-        f(transmute((L_BASE + li) as u32));
-
-        let vi = (si % N_COUNT) / T_COUNT;
-        f(transmute((V_BASE + vi) as u32));
-
-        let ti = si % T_COUNT;
-        if ti > 0 {
-            f(transmute((T_BASE + ti) as u32));
-        }
-    }
-}
-
-/// Returns the canonical decomposition of a character
-pub fn decompose_canonical(c: char, f: |char|) {
-    if (c as uint) < S_BASE || (c as uint) >= (S_BASE + S_COUNT) {
-        decompose::canonical(c, f);
-    } else {
-        decompose_hangul(c, f);
-    }
-}
-
-/// Returns the compatibility decomposition of a character
-pub fn decompose_compatible(c: char, f: |char|) {
-    if (c as uint) < S_BASE || (c as uint) >= (S_BASE + S_COUNT) {
-        decompose::compatibility(c, f);
-    } else {
-        decompose_hangul(c, f);
-    }
-}
-
-///
-/// Returns the hexadecimal Unicode escape of a `char`
-///
-/// The rules are as follows:
-///
-/// - chars in [0,0xff] get 2-digit escapes: `\\xNN`
-/// - chars in [0x100,0xffff] get 4-digit escapes: `\\uNNNN`
-/// - chars above 0x10000 get 8-digit escapes: `\\UNNNNNNNN`
-///
-pub fn escape_unicode(c: char, f: |char|) {
-    // avoid calling str::to_str_radix because we don't really need to allocate
-    // here.
-    f('\\');
-    let pad = match () {
-        _ if c <= '\xff'    => { f('x'); 2 }
-        _ if c <= '\uffff'  => { f('u'); 4 }
-        _                   => { f('U'); 8 }
-    };
-    for offset in range_step::<i32>(4 * (pad - 1), -1, -4) {
-        unsafe {
-            match ((c as i32) >> offset) & 0xf {
-                i @ 0 .. 9 => { f(transmute('0' as i32 + i)); }
-                i => { f(transmute('a' as i32 + (i - 10))); }
-            }
-        }
-    }
-}
-
-///
-/// Returns a 'default' ASCII and C++11-like literal escape of a `char`
-///
-/// 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 unicode escapes; see `escape_unicode`.
-///
-pub fn escape_default(c: char, f: |char|) {
-    match c {
-        '\t' => { f('\\'); f('t'); }
-        '\r' => { f('\\'); f('r'); }
-        '\n' => { f('\\'); f('n'); }
-        '\\' => { f('\\'); f('\\'); }
-        '\'' => { f('\\'); f('\''); }
-        '"'  => { f('\\'); f('"'); }
-        '\x20' .. '\x7e' => { f(c); }
-        _ => c.escape_unicode(f),
-    }
-}
-
-/// Returns the amount of bytes this `char` would need if encoded in UTF-8
-pub fn len_utf8_bytes(c: char) -> uint {
-    static MAX_ONE_B:   uint = 128u;
-    static MAX_TWO_B:   uint = 2048u;
-    static MAX_THREE_B: uint = 65536u;
-    static MAX_FOUR_B:  uint = 2097152u;
-
-    let code = c as uint;
-    match () {
-        _ if code < MAX_ONE_B   => 1u,
-        _ if code < MAX_TWO_B   => 2u,
-        _ if code < MAX_THREE_B => 3u,
-        _ if code < MAX_FOUR_B  => 4u,
-        _                       => fail!("invalid character!"),
-    }
-}
-
-/// Useful functions for Unicode characters.
-pub trait Char {
-    /// Returns whether the specified character is considered a Unicode
-    /// alphabetic code point.
-    fn is_alphabetic(&self) -> bool;
-
-    /// Returns whether the specified character satisfies the 'XID_Start'
-    /// Unicode property.
-    ///
-    /// 'XID_Start' is a Unicode Derived Property specified in
-    /// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
-    /// mostly similar to ID_Start but modified for closure under NFKx.
-    fn is_XID_start(&self) -> bool;
-
-    /// Returns whether the specified `char` satisfies the 'XID_Continue'
-    /// Unicode property.
-    ///
-    /// 'XID_Continue' is a Unicode Derived Property specified in
-    /// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
-    /// mostly similar to 'ID_Continue' but modified for closure under NFKx.
-    fn is_XID_continue(&self) -> bool;
-
-
-    /// Indicates whether a character is in lowercase.
-    ///
-    /// This is defined according to the terms of the Unicode Derived Core
-    /// Property `Lowercase`.
-    fn is_lowercase(&self) -> bool;
-
-    /// Indicates whether a character is in uppercase.
-    ///
-    /// This is defined according to the terms of the Unicode Derived Core
-    /// Property `Uppercase`.
-    fn is_uppercase(&self) -> bool;
-
-    /// Indicates whether a character is whitespace.
-    ///
-    /// Whitespace is defined in terms of the Unicode Property `White_Space`.
-    fn is_whitespace(&self) -> bool;
-
-    /// Indicates whether a character is alphanumeric.
-    ///
-    /// Alphanumericness is defined in terms of the Unicode General Categories
-    /// 'Nd', 'Nl', 'No' and the Derived Core Property 'Alphabetic'.
-    fn is_alphanumeric(&self) -> bool;
-
-    /// Indicates whether a character is a control code point.
-    ///
-    /// Control code points are defined in terms of the Unicode General
-    /// Category `Cc`.
-    fn is_control(&self) -> bool;
-
-    /// Indicates whether the character is numeric (Nd, Nl, or No).
-    fn is_digit(&self) -> bool;
-
-    /// Checks if a `char` parses as a numeric digit in the given radix.
-    ///
-    /// Compared to `is_digit()`, this function only recognizes the characters
-    /// `0-9`, `a-z` and `A-Z`.
-    ///
-    /// # Return value
-    ///
-    /// Returns `true` if `c` is a valid digit under `radix`, and `false`
-    /// otherwise.
-    ///
-    /// # Failure
-    ///
-    /// Fails if given a radix > 36.
-    fn is_digit_radix(&self, radix: uint) -> bool;
-
-    /// Converts a character to the corresponding digit.
-    ///
-    /// # Return value
-    ///
-    /// If `c` is between '0' and '9', the corresponding value between 0 and
-    /// 9. If `c` is 'a' or 'A', 10. If `c` is 'b' or 'B', 11, etc. Returns
-    /// none if the character does not refer to a digit in the given radix.
-    ///
-    /// # Failure
-    ///
-    /// Fails if given a radix outside the range [0..36].
-    fn to_digit(&self, radix: uint) -> Option<uint>;
-
-    /// Converts a character to its lowercase equivalent.
-    ///
-    /// The case-folding performed is the common or simple mapping. See
-    /// `to_uppercase()` for references and more information.
-    ///
-    /// # Return value
-    ///
-    /// Returns the lowercase equivalent of the character, or the character
-    /// itself if no conversion is possible.
-    fn to_lowercase(&self) -> char;
-
-    /// Converts a character to its uppercase equivalent.
-    ///
-    /// The case-folding performed is the common or simple mapping: it maps
-    /// one unicode codepoint (one character in Rust) to its uppercase
-    /// equivalent according to the Unicode database [1]. The additional
-    /// `SpecialCasing.txt` is not considered here, as it expands to multiple
-    /// codepoints in some cases.
-    ///
-    /// A full reference can be found here [2].
-    ///
-    /// # Return value
-    ///
-    /// Returns the uppercase equivalent of the character, or the character
-    /// itself if no conversion was made.
-    ///
-    /// [1]: ftp://ftp.unicode.org/Public/UNIDATA/UnicodeData.txt
-    ///
-    /// [2]: http://www.unicode.org/versions/Unicode4.0.0/ch03.pdf#G33992
-    fn to_uppercase(&self) -> char;
-
-    /// Converts a number to the character representing it.
-    ///
-    /// # Return value
-    ///
-    /// Returns `Some(char)` if `num` represents one digit under `radix`,
-    /// using one character of `0-9` or `a-z`, or `None` if it doesn't.
-    ///
-    /// # Failure
-    ///
-    /// Fails if given a radix > 36.
-    fn from_digit(num: uint, radix: uint) -> Option<char>;
-
-    /// Returns the hexadecimal Unicode escape of a character.
-    ///
-    /// The rules are as follows:
-    ///
-    /// * Characters in [0,0xff] get 2-digit escapes: `\\xNN`
-    /// * Characters in [0x100,0xffff] get 4-digit escapes: `\\uNNNN`.
-    /// * Characters above 0x10000 get 8-digit escapes: `\\UNNNNNNNN`.
-    fn escape_unicode(&self, f: |char|);
-
-    /// Returns a 'default' ASCII and C++11-like literal escape of a
-    /// character.
-    ///
-    /// 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 unicode escapes; see `escape_unicode`.
-    fn escape_default(&self, f: |char|);
-
-    /// Returns the amount of bytes this character would need if encoded in
-    /// UTF-8.
-    fn len_utf8_bytes(&self) -> uint;
-
-    /// Encodes this character as UTF-8 into the provided byte buffer.
-    ///
-    /// The buffer must be at least 4 bytes long or a runtime failure may
-    /// occur.
-    ///
-    /// This will then return the number of bytes written to the slice.
-    fn encode_utf8(&self, dst: &mut [u8]) -> uint;
-
-    /// Encodes this character as UTF-16 into the provided `u16` buffer.
-    ///
-    /// The buffer must be at least 2 elements long or a runtime failure may
-    /// occur.
-    ///
-    /// This will then return the number of `u16`s written to the slice.
-    fn encode_utf16(&self, dst: &mut [u16]) -> uint;
-}
-
-impl Char for char {
-    fn is_alphabetic(&self) -> bool { is_alphabetic(*self) }
-
-    fn is_XID_start(&self) -> bool { is_XID_start(*self) }
-
-    fn is_XID_continue(&self) -> bool { is_XID_continue(*self) }
-
-    fn is_lowercase(&self) -> bool { is_lowercase(*self) }
-
-    fn is_uppercase(&self) -> bool { is_uppercase(*self) }
-
-    fn is_whitespace(&self) -> bool { is_whitespace(*self) }
-
-    fn is_alphanumeric(&self) -> bool { is_alphanumeric(*self) }
-
-    fn is_control(&self) -> bool { is_control(*self) }
-
-    fn is_digit(&self) -> bool { is_digit(*self) }
-
-    fn is_digit_radix(&self, radix: uint) -> bool { is_digit_radix(*self, radix) }
-
-    fn to_digit(&self, radix: uint) -> Option<uint> { to_digit(*self, radix) }
-
-    fn to_lowercase(&self) -> char { to_lowercase(*self) }
-
-    fn to_uppercase(&self) -> char { to_uppercase(*self) }
-
-    fn from_digit(num: uint, radix: uint) -> Option<char> { from_digit(num, radix) }
-
-    fn escape_unicode(&self, f: |char|) { escape_unicode(*self, f) }
-
-    fn escape_default(&self, f: |char|) { escape_default(*self, f) }
-
-    fn len_utf8_bytes(&self) -> uint { len_utf8_bytes(*self) }
-
-    fn encode_utf8(&self, dst: &mut [u8]) -> uint {
-        let code = *self as uint;
-        if code < MAX_ONE_B {
-            dst[0] = code as u8;
-            return 1;
-        } else if code < MAX_TWO_B {
-            dst[0] = (code >> 6u & 31u | TAG_TWO_B) as u8;
-            dst[1] = (code & 63u | TAG_CONT) as u8;
-            return 2;
-        } else if code < MAX_THREE_B {
-            dst[0] = (code >> 12u & 15u | TAG_THREE_B) as u8;
-            dst[1] = (code >> 6u & 63u | TAG_CONT) as u8;
-            dst[2] = (code & 63u | TAG_CONT) as u8;
-            return 3;
-        } else {
-            dst[0] = (code >> 18u & 7u | TAG_FOUR_B) as u8;
-            dst[1] = (code >> 12u & 63u | TAG_CONT) as u8;
-            dst[2] = (code >> 6u & 63u | TAG_CONT) as u8;
-            dst[3] = (code & 63u | TAG_CONT) as u8;
-            return 4;
-        }
-    }
-
-    fn encode_utf16(&self, dst: &mut [u16]) -> uint {
-        let mut ch = *self as uint;
-        if (ch & 0xFFFF_u) == ch {
-            // The BMP falls through (assuming non-surrogate, as it
-            // should)
-            assert!(ch <= 0xD7FF_u || ch >= 0xE000_u);
-            dst[0] = ch as u16;
-            1
-        } else {
-            // Supplementary planes break into surrogates.
-            assert!(ch >= 0x1_0000_u && ch <= 0x10_FFFF_u);
-            ch -= 0x1_0000_u;
-            dst[0] = 0xD800_u16 | ((ch >> 10) as u16);
-            dst[1] = 0xDC00_u16 | ((ch as u16) & 0x3FF_u16);
-            2
-        }
-    }
-}
-
-#[cfg(not(test))]
-impl Eq for char {
-    #[inline]
-    fn eq(&self, other: &char) -> bool { (*self) == (*other) }
-}
-
-#[cfg(not(test))]
-impl Ord for char {
-    #[inline]
-    fn lt(&self, other: &char) -> bool { *self < *other }
-}
-
-#[cfg(not(test))]
-impl Default for char {
-    #[inline]
-    fn default() -> char { '\x00' }
-}
-
-#[test]
-fn test_is_lowercase() {
-    assert!('a'.is_lowercase());
-    assert!('ö'.is_lowercase());
-    assert!('ß'.is_lowercase());
-    assert!(!'Ü'.is_lowercase());
-    assert!(!'P'.is_lowercase());
-}
-
-#[test]
-fn test_is_uppercase() {
-    assert!(!'h'.is_uppercase());
-    assert!(!'ä'.is_uppercase());
-    assert!(!'ß'.is_uppercase());
-    assert!('Ö'.is_uppercase());
-    assert!('T'.is_uppercase());
-}
-
-#[test]
-fn test_is_whitespace() {
-    assert!(' '.is_whitespace());
-    assert!('\u2007'.is_whitespace());
-    assert!('\t'.is_whitespace());
-    assert!('\n'.is_whitespace());
-    assert!(!'a'.is_whitespace());
-    assert!(!'_'.is_whitespace());
-    assert!(!'\u0000'.is_whitespace());
-}
-
-#[test]
-fn test_to_digit() {
-    assert_eq!('0'.to_digit(10u), Some(0u));
-    assert_eq!('1'.to_digit(2u), Some(1u));
-    assert_eq!('2'.to_digit(3u), Some(2u));
-    assert_eq!('9'.to_digit(10u), Some(9u));
-    assert_eq!('a'.to_digit(16u), Some(10u));
-    assert_eq!('A'.to_digit(16u), Some(10u));
-    assert_eq!('b'.to_digit(16u), Some(11u));
-    assert_eq!('B'.to_digit(16u), Some(11u));
-    assert_eq!('z'.to_digit(36u), Some(35u));
-    assert_eq!('Z'.to_digit(36u), Some(35u));
-    assert_eq!(' '.to_digit(10u), None);
-    assert_eq!('$'.to_digit(36u), None);
-}
-
-#[test]
-fn test_to_lowercase() {
-    assert_eq!('A'.to_lowercase(), 'a');
-    assert_eq!('Ö'.to_lowercase(), 'ö');
-    assert_eq!('ß'.to_lowercase(), 'ß');
-    assert_eq!('Ü'.to_lowercase(), 'ü');
-    assert_eq!('💩'.to_lowercase(), '💩');
-    assert_eq!('Σ'.to_lowercase(), 'σ');
-    assert_eq!('Τ'.to_lowercase(), 'τ');
-    assert_eq!('Ι'.to_lowercase(), 'ι');
-    assert_eq!('Γ'.to_lowercase(), 'γ');
-    assert_eq!('Μ'.to_lowercase(), 'μ');
-    assert_eq!('Α'.to_lowercase(), 'α');
-    assert_eq!('Σ'.to_lowercase(), 'σ');
-}
-
-#[test]
-fn test_to_uppercase() {
-    assert_eq!('a'.to_uppercase(), 'A');
-    assert_eq!('ö'.to_uppercase(), 'Ö');
-    assert_eq!('ß'.to_uppercase(), 'ß'); // not ẞ: Latin capital letter sharp s
-    assert_eq!('ü'.to_uppercase(), 'Ü');
-    assert_eq!('💩'.to_uppercase(), '💩');
-
-    assert_eq!('σ'.to_uppercase(), 'Σ');
-    assert_eq!('τ'.to_uppercase(), 'Τ');
-    assert_eq!('ι'.to_uppercase(), 'Ι');
-    assert_eq!('γ'.to_uppercase(), 'Γ');
-    assert_eq!('μ'.to_uppercase(), 'Μ');
-    assert_eq!('α'.to_uppercase(), 'Α');
-    assert_eq!('ς'.to_uppercase(), 'Σ');
-}
-
-#[test]
-fn test_is_control() {
-    assert!('\u0000'.is_control());
-    assert!('\u0003'.is_control());
-    assert!('\u0006'.is_control());
-    assert!('\u0009'.is_control());
-    assert!('\u007f'.is_control());
-    assert!('\u0092'.is_control());
-    assert!(!'\u0020'.is_control());
-    assert!(!'\u0055'.is_control());
-    assert!(!'\u0068'.is_control());
-}
-
-#[test]
-fn test_is_digit() {
-   assert!('2'.is_digit());
-   assert!('7'.is_digit());
-   assert!(!'c'.is_digit());
-   assert!(!'i'.is_digit());
-   assert!(!'z'.is_digit());
-   assert!(!'Q'.is_digit());
-}
-
-#[test]
-fn test_escape_default() {
-    fn string(c: char) -> ~str {
-        let mut result = StrBuf::new();
-        escape_default(c, |c| { result.push_char(c); });
-        return result.into_owned();
-    }
-    assert_eq!(string('\n'), "\\n".to_owned());
-    assert_eq!(string('\r'), "\\r".to_owned());
-    assert_eq!(string('\''), "\\'".to_owned());
-    assert_eq!(string('"'), "\\\"".to_owned());
-    assert_eq!(string(' '), " ".to_owned());
-    assert_eq!(string('a'), "a".to_owned());
-    assert_eq!(string('~'), "~".to_owned());
-    assert_eq!(string('\x00'), "\\x00".to_owned());
-    assert_eq!(string('\x1f'), "\\x1f".to_owned());
-    assert_eq!(string('\x7f'), "\\x7f".to_owned());
-    assert_eq!(string('\xff'), "\\xff".to_owned());
-    assert_eq!(string('\u011b'), "\\u011b".to_owned());
-    assert_eq!(string('\U0001d4b6'), "\\U0001d4b6".to_owned());
-}
-
-#[test]
-fn test_escape_unicode() {
-    fn string(c: char) -> ~str {
-        let mut result = StrBuf::new();
-        escape_unicode(c, |c| { result.push_char(c); });
-        return result.into_owned();
-    }
-    assert_eq!(string('\x00'), "\\x00".to_owned());
-    assert_eq!(string('\n'), "\\x0a".to_owned());
-    assert_eq!(string(' '), "\\x20".to_owned());
-    assert_eq!(string('a'), "\\x61".to_owned());
-    assert_eq!(string('\u011b'), "\\u011b".to_owned());
-    assert_eq!(string('\U0001d4b6'), "\\U0001d4b6".to_owned());
-}
-
-#[test]
-fn test_to_str() {
-    use to_str::ToStr;
-    let s = 't'.to_str();
-    assert_eq!(s, "t".to_owned());
-}
-
-#[test]
-fn test_encode_utf8() {
-    fn check(input: char, expect: &[u8]) {
-        let mut buf = [0u8, ..4];
-        let n = input.encode_utf8(buf /* as mut slice! */);
-        assert_eq!(buf.slice_to(n), expect);
-    }
-
-    check('x', [0x78]);
-    check('\u00e9', [0xc3, 0xa9]);
-    check('\ua66e', [0xea, 0x99, 0xae]);
-    check('\U0001f4a9', [0xf0, 0x9f, 0x92, 0xa9]);
-}
-
-#[test]
-fn test_encode_utf16() {
-    fn check(input: char, expect: &[u16]) {
-        let mut buf = [0u16, ..2];
-        let n = input.encode_utf16(buf /* as mut slice! */);
-        assert_eq!(buf.slice_to(n), expect);
-    }
-
-    check('x', [0x0078]);
-    check('\u00e9', [0x00e9]);
-    check('\ua66e', [0xa66e]);
-    check('\U0001f4a9', [0xd83d, 0xdca9]);
-}
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 44684ba97c2..26e8e18909c 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -138,6 +138,7 @@ extern crate core;
 #[cfg(not(test))] pub use ty = core::ty;
 
 pub use core::cast;
+pub use core::char;
 pub use core::container;
 pub use core::intrinsics;
 pub use core::mem;
@@ -188,7 +189,6 @@ pub mod prelude;
 
 pub mod unit;
 pub mod bool;
-pub mod char;
 pub mod tuple;
 
 pub mod slice;