impl char

9 files changed, 381 insertions, 1 deletions

diff --git a/src/libcollections/lib.rs b/src/libcollections/lib.rs
index e90186d63b4..dd23bcbaf81 100644
--- a/src/libcollections/lib.rs
+++ b/src/libcollections/lib.rs
@@ -166,7 +166,6 @@ mod prelude {
 
     // from other crates.
     pub use alloc::boxed::Box;
-    pub use unicode::char::CharExt;
 
     // from collections.
     pub use borrow::IntoCow;
diff --git a/src/libstd/num/strconv.rs b/src/libstd/num/strconv.rs
index 5fdd42dbc7a..fa24e9fd5af 100644
--- a/src/libstd/num/strconv.rs
+++ b/src/libstd/num/strconv.rs
@@ -16,7 +16,10 @@ use self::ExponentFormat::*;
 use self::SignificantDigits::*;
 use self::SignFormat::*;
 
+#[cfg(stage0)]
 use char::{self, CharExt};
+#[cfg(not(stage0))]
+use char;
 use num::{self, Int, Float, ToPrimitive};
 use num::FpCategory as Fp;
 use ops::FnMut;
diff --git a/src/libstd/old_io/mod.rs b/src/libstd/old_io/mod.rs
index 332b941bcc0..711faa98bd9 100644
--- a/src/libstd/old_io/mod.rs
+++ b/src/libstd/old_io/mod.rs
@@ -251,6 +251,7 @@ pub use self::FileMode::*;
 pub use self::FileAccess::*;
 pub use self::IoErrorKind::*;
 
+#[cfg(stage0)]
 use char::CharExt;
 use default::Default;
 use error::Error;
diff --git a/src/libstd/old_path/windows.rs b/src/libstd/old_path/windows.rs
index 838710b1aec..1387d531001 100644
--- a/src/libstd/old_path/windows.rs
+++ b/src/libstd/old_path/windows.rs
@@ -15,6 +15,7 @@
 use self::PathPrefix::*;
 
 use ascii::AsciiExt;
+#[cfg(stage0)]
 use char::CharExt;
 use clone::Clone;
 use cmp::{Ordering, Eq, Ord, PartialEq, PartialOrd};
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index 2159e300744..29c779df4d2 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -159,6 +159,7 @@ mod platform {
     use core::prelude::*;
     use ascii::*;
 
+    #[cfg(stage0)]
     use char::CharExt as UnicodeCharExt;
     use super::{os_str_as_u8_slice, u8_slice_as_os_str, Prefix};
     use ffi::OsStr;
diff --git a/src/libstd/prelude/v1.rs b/src/libstd/prelude/v1.rs
index 31aac333859..b244f785852 100644
--- a/src/libstd/prelude/v1.rs
+++ b/src/libstd/prelude/v1.rs
@@ -25,6 +25,7 @@
 // Reexported types and traits
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)] pub use boxed::Box;
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)] pub use char::CharExt;
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libunicode/char.rs b/src/libunicode/char.rs
index bcc2820e381..56bc0389b74 100644
--- a/src/libunicode/char.rs
+++ b/src/libunicode/char.rs
@@ -41,6 +41,7 @@ pub use normalize::{decompose_canonical, decompose_compatible, compose};
 pub use tables::normalization::canonical_combining_class;
 pub use tables::UNICODE_VERSION;
 
+#[cfg(stage0)]
 /// Functionality for manipulating `char`.
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait CharExt {
@@ -374,6 +375,7 @@ pub trait CharExt {
     fn width(self, is_cjk: bool) -> Option<usize>;
 }
 
+#[cfg(stage0)]
 #[stable(feature = "rust1", since = "1.0.0")]
 impl CharExt for char {
     fn is_digit(self, radix: u32) -> bool { C::is_digit(self, radix) }
@@ -467,3 +469,373 @@ impl Iterator for ToUppercase {
     type Item = char;
     fn next(&mut self) -> Option<char> { self.0.take() }
 }
+
+#[cfg(not(stage0))]
+#[stable(feature = "rust1", since = "1.0.0")]
+#[lang = "char"]
+impl char {
+    /// Checks if a `char` parses as a numeric digit in the given radix.
+    ///
+    /// Compared to `is_numeric()`, 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.
+    ///
+    /// # Panics
+    ///
+    /// Panics if given a radix > 36.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let c = '1';
+    ///
+    /// assert!(c.is_digit(10));
+    ///
+    /// assert!('f'.is_digit(16));
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_digit(self, radix: u32) -> bool { C::is_digit(self, radix) }
+
+    /// 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.
+    ///
+    /// # Panics
+    ///
+    /// Panics if given a radix outside the range [0..36].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let c = '1';
+    ///
+    /// assert_eq!(c.to_digit(10), Some(1));
+    ///
+    /// assert_eq!('f'.to_digit(16), Some(15));
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn to_digit(self, radix: u32) -> Option<u32> { C::to_digit(self, radix) }
+
+    /// Returns an iterator that yields the hexadecimal Unicode escape of a
+    /// character, as `char`s.
+    ///
+    /// All characters are escaped with Rust syntax of the form `\\u{NNNN}`
+    /// where `NNNN` is the shortest hexadecimal representation of the code
+    /// point.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// for i in '❤'.escape_unicode() {
+    ///     println!("{}", i);
+    /// }
+    /// ```
+    ///
+    /// This prints:
+    ///
+    /// ```text
+    /// \
+    /// u
+    /// {
+    /// 2
+    /// 7
+    /// 6
+    /// 4
+    /// }
+    /// ```
+    ///
+    /// Collecting into a `String`:
+    ///
+    /// ```
+    /// let heart: String = '❤'.escape_unicode().collect();
+    ///
+    /// assert_eq!(heart, r"\u{2764}");
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn escape_unicode(self) -> EscapeUnicode { C::escape_unicode(self) }
+
+    /// Returns an iterator that yields the 'default' ASCII and
+    /// C++11-like literal escape of a character, as `char`s.
+    ///
+    /// 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`.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// for i in '"'.escape_default() {
+    ///     println!("{}", i);
+    /// }
+    /// ```
+    ///
+    /// This prints:
+    ///
+    /// ```text
+    /// \
+    /// "
+    /// ```
+    ///
+    /// Collecting into a `String`:
+    ///
+    /// ```
+    /// let quote: String = '"'.escape_default().collect();
+    ///
+    /// assert_eq!(quote, "\\\"");
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn escape_default(self) -> EscapeDefault { C::escape_default(self) }
+
+    /// Returns the number of bytes this character would need if encoded in
+    /// UTF-8.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let n = 'ß'.len_utf8();
+    ///
+    /// assert_eq!(n, 2);
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn len_utf8(self) -> usize { C::len_utf8(self) }
+
+    /// Returns the number of 16-bit code units this character would need if
+    /// encoded in UTF-16.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// let n = 'ß'.len_utf16();
+    ///
+    /// assert_eq!(n, 1);
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn len_utf16(self) -> usize { C::len_utf16(self) }
+
+    /// Encodes this character as UTF-8 into the provided byte buffer, and then
+    /// returns the number of bytes written.
+    ///
+    /// If the buffer is not large enough, nothing will be written into it and a
+    /// `None` will be returned. A buffer of length four is large enough to
+    /// encode any `char`.
+    ///
+    /// # Examples
+    ///
+    /// In both of these examples, 'ß' takes two bytes to encode.
+    ///
+    /// ```
+    /// let mut b = [0; 2];
+    ///
+    /// let result = 'ß'.encode_utf8(&mut b);
+    ///
+    /// assert_eq!(result, Some(2));
+    /// ```
+    ///
+    /// A buffer that's too small:
+    ///
+    /// ```
+    /// let mut b = [0; 1];
+    ///
+    /// let result = 'ß'.encode_utf8(&mut b);
+    ///
+    /// assert_eq!(result, None);
+    /// ```
+    #[unstable(feature = "unicode",
+               reason = "pending decision about Iterator/Writer/Reader")]
+    pub fn encode_utf8(self, dst: &mut [u8]) -> Option<usize> { C::encode_utf8(self, dst) }
+
+    /// Encodes this character as UTF-16 into the provided `u16` buffer, and
+    /// then returns the number of `u16`s written.
+    ///
+    /// If the buffer is not large enough, nothing will be written into it and a
+    /// `None` will be returned. A buffer of length 2 is large enough to encode
+    /// any `char`.
+    ///
+    /// # Examples
+    ///
+    /// In both of these examples, 'ß' takes one `u16` to encode.
+    ///
+    /// ```
+    /// let mut b = [0; 1];
+    ///
+    /// let result = 'ß'.encode_utf16(&mut b);
+    ///
+    /// assert_eq!(result, Some(1));
+    /// ```
+    ///
+    /// A buffer that's too small:
+    ///
+    /// ```
+    /// let mut b = [0; 0];
+    ///
+    /// let result = 'ß'.encode_utf8(&mut b);
+    ///
+    /// assert_eq!(result, None);
+    /// ```
+    #[unstable(feature = "unicode",
+               reason = "pending decision about Iterator/Writer/Reader")]
+    pub fn encode_utf16(self, dst: &mut [u16]) -> Option<usize> { C::encode_utf16(self, dst) }
+
+    /// Returns whether the specified character is considered a Unicode
+    /// alphabetic code point.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_alphabetic(self) -> bool {
+        match self {
+            'a' ... 'z' | 'A' ... 'Z' => true,
+            c if c > '\x7f' => derived_property::Alphabetic(c),
+            _ => false
+        }
+    }
+
+    /// 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.
+    #[unstable(feature = "unicode",
+               reason = "mainly needed for compiler internals")]
+    pub fn is_xid_start(self) -> bool { derived_property::XID_Start(self) }
+
+    /// 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.
+    #[unstable(feature = "unicode",
+               reason = "mainly needed for compiler internals")]
+    pub fn is_xid_continue(self) -> bool { derived_property::XID_Continue(self) }
+
+    /// Indicates whether a character is in lowercase.
+    ///
+    /// This is defined according to the terms of the Unicode Derived Core
+    /// Property `Lowercase`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_lowercase(self) -> bool {
+        match self {
+            'a' ... 'z' => true,
+            c if c > '\x7f' => derived_property::Lowercase(c),
+            _ => false
+        }
+    }
+
+    /// Indicates whether a character is in uppercase.
+    ///
+    /// This is defined according to the terms of the Unicode Derived Core
+    /// Property `Uppercase`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_uppercase(self) -> bool {
+        match self {
+            'A' ... 'Z' => true,
+            c if c > '\x7f' => derived_property::Uppercase(c),
+            _ => false
+        }
+    }
+
+    /// Indicates whether a character is whitespace.
+    ///
+    /// Whitespace is defined in terms of the Unicode Property `White_Space`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_whitespace(self) -> bool {
+        match self {
+            ' ' | '\x09' ... '\x0d' => true,
+            c if c > '\x7f' => property::White_Space(c),
+            _ => false
+        }
+    }
+
+    /// 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'.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_alphanumeric(self) -> bool {
+        self.is_alphabetic() || self.is_numeric()
+    }
+
+    /// Indicates whether a character is a control code point.
+    ///
+    /// Control code points are defined in terms of the Unicode General
+    /// Category `Cc`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_control(self) -> bool { general_category::Cc(self) }
+
+    /// Indicates whether the character is numeric (Nd, Nl, or No).
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn is_numeric(self) -> bool {
+        match self {
+            '0' ... '9' => true,
+            c if c > '\x7f' => general_category::N(c),
+            _ => false
+        }
+    }
+
+    /// 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 an iterator which yields the characters corresponding to the
+    /// lowercase equivalent of the character. If no conversion is possible then
+    /// the input character is returned.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn to_lowercase(self) -> ToLowercase {
+        ToLowercase(Some(conversions::to_lower(self)))
+    }
+
+    /// Converts a character to its uppercase equivalent.
+    ///
+    /// The case-folding performed is the common or simple mapping: it maps
+    /// one Unicode codepoint to its uppercase equivalent according to the
+    /// Unicode database [1]. The additional [`SpecialCasing.txt`] is not yet
+    /// considered here, but the iterator returned will soon support this form
+    /// of case folding.
+    ///
+    /// A full reference can be found here [2].
+    ///
+    /// # Return value
+    ///
+    /// Returns an iterator which yields the characters corresponding to the
+    /// uppercase equivalent of the character. If no conversion is possible then
+    /// the input character is returned.
+    ///
+    /// [1]: ftp://ftp.unicode.org/Public/UNIDATA/UnicodeData.txt
+    ///
+    /// [`SpecialCasing`.txt`]: ftp://ftp.unicode.org/Public/UNIDATA/SpecialCasing.txt
+    ///
+    /// [2]: http://www.unicode.org/versions/Unicode4.0.0/ch03.pdf#G33992
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn to_uppercase(self) -> ToUppercase {
+        ToUppercase(Some(conversions::to_upper(self)))
+    }
+
+    /// Returns this character's displayed width in columns, or `None` if it is a
+    /// control character other than `'\x00'`.
+    ///
+    /// `is_cjk` determines behavior for characters in the Ambiguous category:
+    /// if `is_cjk` is `true`, these are 2 columns wide; otherwise, they are 1.
+    /// In CJK contexts, `is_cjk` should be `true`, else it should be `false`.
+    /// [Unicode Standard Annex #11](http://www.unicode.org/reports/tr11/)
+    /// recommends that these characters be treated as 1 column (i.e.,
+    /// `is_cjk` = `false`) if the context cannot be reliably determined.
+    #[unstable(feature = "unicode",
+               reason = "needs expert opinion. is_cjk flag stands out as ugly")]
+    pub fn width(self, is_cjk: bool) -> Option<usize> { charwidth::width(self, is_cjk) }
+}
diff --git a/src/libunicode/lib.rs b/src/libunicode/lib.rs
index fadf91f33bc..a09c0cb3bd6 100644
--- a/src/libunicode/lib.rs
+++ b/src/libunicode/lib.rs
@@ -24,6 +24,7 @@
 #![cfg_attr(stage0, feature(custom_attribute))]
 #![crate_name = "unicode"]
 #![unstable(feature = "unicode")]
+#![feature(lang_items)]
 #![feature(staged_api)]
 #![staged_api]
 #![crate_type = "rlib"]
diff --git a/src/libunicode/u_str.rs b/src/libunicode/u_str.rs
index 050d2adf050..6a80f3bc2c1 100644
--- a/src/libunicode/u_str.rs
+++ b/src/libunicode/u_str.rs
@@ -26,6 +26,7 @@ use core::num::Int;
 use core::slice;
 use core::str::Split;
 
+#[cfg(stage0)]
 use char::CharExt as UCharExt; // conflicts with core::prelude::CharExt
 use tables::grapheme::GraphemeCat;