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 {
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) }
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) }
+}
projects / rust.git / commitdiff