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Diffstat (limited to 'src/libcore/char/methods.rs')
| -rw-r--r-- | src/libcore/char/methods.rs | 1687 |
1 files changed, 0 insertions, 1687 deletions
diff --git a/src/libcore/char/methods.rs b/src/libcore/char/methods.rs deleted file mode 100644 index 2603ecf428c..00000000000 --- a/src/libcore/char/methods.rs +++ /dev/null @@ -1,1687 +0,0 @@ -//! impl char {} - -use crate::slice; -use crate::str::from_utf8_unchecked_mut; -use crate::unicode::printable::is_printable; -use crate::unicode::{self, conversions}; - -use super::*; - -#[lang = "char"] -impl char { - /// The highest valid code point a `char` can have. - /// - /// A `char` is a [Unicode Scalar Value], which means that it is a [Code - /// Point], but only ones within a certain range. `MAX` is the highest valid - /// code point that's a valid [Unicode Scalar Value]. - /// - /// [Unicode Scalar Value]: http://www.unicode.org/glossary/#unicode_scalar_value - /// [Code Point]: http://www.unicode.org/glossary/#code_point - #[unstable(feature = "assoc_char_consts", reason = "recently added", issue = "71763")] - pub const MAX: char = '\u{10ffff}'; - - /// `U+FFFD REPLACEMENT CHARACTER` (�) is used in Unicode to represent a - /// decoding error. - /// - /// It can occur, for example, when giving ill-formed UTF-8 bytes to - /// [`String::from_utf8_lossy`](string/struct.String.html#method.from_utf8_lossy). - #[unstable(feature = "assoc_char_consts", reason = "recently added", issue = "71763")] - pub const REPLACEMENT_CHARACTER: char = '\u{FFFD}'; - - /// The version of [Unicode](http://www.unicode.org/) that the Unicode parts of - /// `char` and `str` methods are based on. - /// - /// New versions of Unicode are released regularly and subsequently all methods - /// in the standard library depending on Unicode are updated. Therefore the - /// behavior of some `char` and `str` methods and the value of this constant - /// changes over time. This is *not* considered to be a breaking change. - /// - /// The version numbering scheme is explained in - /// [Unicode 11.0 or later, Section 3.1 Versions of the Unicode Standard](https://www.unicode.org/versions/Unicode11.0.0/ch03.pdf#page=4). - #[unstable(feature = "assoc_char_consts", reason = "recently added", issue = "71763")] - pub const UNICODE_VERSION: (u8, u8, u8) = crate::unicode::UNICODE_VERSION; - - /// Creates an iterator over the UTF-16 encoded code points in `iter`, - /// returning unpaired surrogates as `Err`s. - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// use std::char::decode_utf16; - /// - /// // 𝄞mus<invalid>ic<invalid> - /// let v = [ - /// 0xD834, 0xDD1E, 0x006d, 0x0075, 0x0073, 0xDD1E, 0x0069, 0x0063, 0xD834, - /// ]; - /// - /// assert_eq!( - /// decode_utf16(v.iter().cloned()) - /// .map(|r| r.map_err(|e| e.unpaired_surrogate())) - /// .collect::<Vec<_>>(), - /// vec![ - /// Ok('𝄞'), - /// Ok('m'), Ok('u'), Ok('s'), - /// Err(0xDD1E), - /// Ok('i'), Ok('c'), - /// Err(0xD834) - /// ] - /// ); - /// ``` - /// - /// A lossy decoder can be obtained by replacing `Err` results with the replacement character: - /// - /// ``` - /// use std::char::{decode_utf16, REPLACEMENT_CHARACTER}; - /// - /// // 𝄞mus<invalid>ic<invalid> - /// let v = [ - /// 0xD834, 0xDD1E, 0x006d, 0x0075, 0x0073, 0xDD1E, 0x0069, 0x0063, 0xD834, - /// ]; - /// - /// assert_eq!( - /// decode_utf16(v.iter().cloned()) - /// .map(|r| r.unwrap_or(REPLACEMENT_CHARACTER)) - /// .collect::<String>(), - /// "𝄞mus�ic�" - /// ); - /// ``` - #[unstable(feature = "assoc_char_funcs", reason = "recently added", issue = "71763")] - #[inline] - pub fn decode_utf16<I: IntoIterator<Item = u16>>(iter: I) -> DecodeUtf16<I::IntoIter> { - super::decode::decode_utf16(iter) - } - - /// Converts a `u32` to a `char`. - /// - /// Note that all `char`s are valid [`u32`]s, and can be cast to one with - /// `as`: - /// - /// ``` - /// let c = '💯'; - /// let i = c as u32; - /// - /// assert_eq!(128175, i); - /// ``` - /// - /// However, the reverse is not true: not all valid [`u32`]s are valid - /// `char`s. `from_u32()` will return `None` if the input is not a valid value - /// for a `char`. - /// - /// [`u32`]: primitive.u32.html - /// - /// For an unsafe version of this function which ignores these checks, see - /// [`from_u32_unchecked`]. - /// - /// [`from_u32_unchecked`]: #method.from_u32_unchecked - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// use std::char; - /// - /// let c = char::from_u32(0x2764); - /// - /// assert_eq!(Some('❤'), c); - /// ``` - /// - /// Returning `None` when the input is not a valid `char`: - /// - /// ``` - /// use std::char; - /// - /// let c = char::from_u32(0x110000); - /// - /// assert_eq!(None, c); - /// ``` - #[unstable(feature = "assoc_char_funcs", reason = "recently added", issue = "71763")] - #[inline] - pub fn from_u32(i: u32) -> Option<char> { - super::convert::from_u32(i) - } - - /// Converts a `u32` to a `char`, ignoring validity. - /// - /// Note that all `char`s are valid [`u32`]s, and can be cast to one with - /// `as`: - /// - /// ``` - /// let c = '💯'; - /// let i = c as u32; - /// - /// assert_eq!(128175, i); - /// ``` - /// - /// However, the reverse is not true: not all valid [`u32`]s are valid - /// `char`s. `from_u32_unchecked()` will ignore this, and blindly cast to - /// `char`, possibly creating an invalid one. - /// - /// [`u32`]: primitive.u32.html - /// - /// # Safety - /// - /// This function is unsafe, as it may construct invalid `char` values. - /// - /// For a safe version of this function, see the [`from_u32`] function. - /// - /// [`from_u32`]: #method.from_u32 - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// use std::char; - /// - /// let c = unsafe { char::from_u32_unchecked(0x2764) }; - /// - /// assert_eq!('❤', c); - /// ``` - #[unstable(feature = "assoc_char_funcs", reason = "recently added", issue = "71763")] - #[inline] - pub unsafe fn from_u32_unchecked(i: u32) -> char { - // SAFETY: the safety contract must be upheld by the caller. - unsafe { super::convert::from_u32_unchecked(i) } - } - - /// Converts a digit in the given radix to a `char`. - /// - /// A 'radix' here is sometimes also called a 'base'. A radix of two - /// indicates a binary number, a radix of ten, decimal, and a radix of - /// sixteen, hexadecimal, to give some common values. Arbitrary - /// radices are supported. - /// - /// `from_digit()` will return `None` if the input is not a digit in - /// the given radix. - /// - /// # Panics - /// - /// Panics if given a radix larger than 36. - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// use std::char; - /// - /// let c = char::from_digit(4, 10); - /// - /// assert_eq!(Some('4'), c); - /// - /// // Decimal 11 is a single digit in base 16 - /// let c = char::from_digit(11, 16); - /// - /// assert_eq!(Some('b'), c); - /// ``` - /// - /// Returning `None` when the input is not a digit: - /// - /// ``` - /// use std::char; - /// - /// let c = char::from_digit(20, 10); - /// - /// assert_eq!(None, c); - /// ``` - /// - /// Passing a large radix, causing a panic: - /// - /// ```should_panic - /// use std::char; - /// - /// // this panics - /// char::from_digit(1, 37); - /// ``` - #[unstable(feature = "assoc_char_funcs", reason = "recently added", issue = "71763")] - #[inline] - pub fn from_digit(num: u32, radix: u32) -> Option<char> { - super::convert::from_digit(num, radix) - } - - /// Checks if a `char` is a digit in the given radix. - /// - /// A 'radix' here is sometimes also called a 'base'. A radix of two - /// indicates a binary number, a radix of ten, decimal, and a radix of - /// sixteen, hexadecimal, to give some common values. Arbitrary - /// radices are supported. - /// - /// Compared to `is_numeric()`, this function only recognizes the characters - /// `0-9`, `a-z` and `A-Z`. - /// - /// 'Digit' is defined to be only the following characters: - /// - /// * `0-9` - /// * `a-z` - /// * `A-Z` - /// - /// For a more comprehensive understanding of 'digit', see [`is_numeric`][is_numeric]. - /// - /// [is_numeric]: #method.is_numeric - /// - /// # Panics - /// - /// Panics if given a radix larger than 36. - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!('1'.is_digit(10)); - /// assert!('f'.is_digit(16)); - /// assert!(!'f'.is_digit(10)); - /// ``` - /// - /// Passing a large radix, causing a panic: - /// - /// ```should_panic - /// // this panics - /// '1'.is_digit(37); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_digit(self, radix: u32) -> bool { - self.to_digit(radix).is_some() - } - - /// Converts a `char` to a digit in the given radix. - /// - /// A 'radix' here is sometimes also called a 'base'. A radix of two - /// indicates a binary number, a radix of ten, decimal, and a radix of - /// sixteen, hexadecimal, to give some common values. Arbitrary - /// radices are supported. - /// - /// 'Digit' is defined to be only the following characters: - /// - /// * `0-9` - /// * `a-z` - /// * `A-Z` - /// - /// # Errors - /// - /// Returns `None` if the `char` does not refer to a digit in the given radix. - /// - /// # Panics - /// - /// Panics if given a radix larger than 36. - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert_eq!('1'.to_digit(10), Some(1)); - /// assert_eq!('f'.to_digit(16), Some(15)); - /// ``` - /// - /// Passing a non-digit results in failure: - /// - /// ``` - /// assert_eq!('f'.to_digit(10), None); - /// assert_eq!('z'.to_digit(16), None); - /// ``` - /// - /// Passing a large radix, causing a panic: - /// - /// ```should_panic - /// // this panics - /// '1'.to_digit(37); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn to_digit(self, radix: u32) -> Option<u32> { - assert!(radix <= 36, "to_digit: radix is too high (maximum 36)"); - - // the code is split up here to improve execution speed for cases where - // the `radix` is constant and 10 or smaller - let val = if radix <= 10 { - match self { - '0'..='9' => self as u32 - '0' as u32, - _ => return None, - } - } else { - match self { - '0'..='9' => self as u32 - '0' as u32, - 'a'..='z' => self as u32 - 'a' as u32 + 10, - 'A'..='Z' => self as u32 - 'A' as u32 + 10, - _ => return None, - } - }; - - if val < radix { Some(val) } else { None } - } - - /// Returns an iterator that yields the hexadecimal Unicode escape of a - /// character as `char`s. - /// - /// This will escape characters with the Rust syntax of the form - /// `\u{NNNNNN}` where `NNNNNN` is a hexadecimal representation. - /// - /// # Examples - /// - /// As an iterator: - /// - /// ``` - /// for c in '❤'.escape_unicode() { - /// print!("{}", c); - /// } - /// println!(); - /// ``` - /// - /// Using `println!` directly: - /// - /// ``` - /// println!("{}", '❤'.escape_unicode()); - /// ``` - /// - /// Both are equivalent to: - /// - /// ``` - /// println!("\\u{{2764}}"); - /// ``` - /// - /// Using `to_string`: - /// - /// ``` - /// assert_eq!('❤'.escape_unicode().to_string(), "\\u{2764}"); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn escape_unicode(self) -> EscapeUnicode { - let c = self as u32; - - // or-ing 1 ensures that for c==0 the code computes that one - // digit should be printed and (which is the same) avoids the - // (31 - 32) underflow - let msb = 31 - (c | 1).leading_zeros(); - - // the index of the most significant hex digit - let ms_hex_digit = msb / 4; - EscapeUnicode { - c: self, - state: EscapeUnicodeState::Backslash, - hex_digit_idx: ms_hex_digit as usize, - } - } - - /// An extended version of `escape_debug` that optionally permits escaping - /// Extended Grapheme codepoints. This allows us to format characters like - /// nonspacing marks better when they're at the start of a string. - #[inline] - pub(crate) fn escape_debug_ext(self, escape_grapheme_extended: bool) -> EscapeDebug { - let init_state = match self { - '\t' => EscapeDefaultState::Backslash('t'), - '\r' => EscapeDefaultState::Backslash('r'), - '\n' => EscapeDefaultState::Backslash('n'), - '\\' | '\'' | '"' => EscapeDefaultState::Backslash(self), - _ if escape_grapheme_extended && self.is_grapheme_extended() => { - EscapeDefaultState::Unicode(self.escape_unicode()) - } - _ if is_printable(self) => EscapeDefaultState::Char(self), - _ => EscapeDefaultState::Unicode(self.escape_unicode()), - }; - EscapeDebug(EscapeDefault { state: init_state }) - } - - /// Returns an iterator that yields the literal escape code of a character - /// as `char`s. - /// - /// This will escape the characters similar to the `Debug` implementations - /// of `str` or `char`. - /// - /// # Examples - /// - /// As an iterator: - /// - /// ``` - /// for c in '\n'.escape_debug() { - /// print!("{}", c); - /// } - /// println!(); - /// ``` - /// - /// Using `println!` directly: - /// - /// ``` - /// println!("{}", '\n'.escape_debug()); - /// ``` - /// - /// Both are equivalent to: - /// - /// ``` - /// println!("\\n"); - /// ``` - /// - /// Using `to_string`: - /// - /// ``` - /// assert_eq!('\n'.escape_debug().to_string(), "\\n"); - /// ``` - #[stable(feature = "char_escape_debug", since = "1.20.0")] - #[inline] - pub fn escape_debug(self) -> EscapeDebug { - self.escape_debug_ext(true) - } - - /// Returns an iterator that yields the literal escape code 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 is escaped as `\t`. - /// * Carriage return is escaped as `\r`. - /// * Line feed is escaped as `\n`. - /// * Single quote is escaped as `\'`. - /// * Double quote is escaped as `\"`. - /// * Backslash is escaped as `\\`. - /// * Any character in the 'printable ASCII' range `0x20` .. `0x7e` - /// inclusive is not escaped. - /// * All other characters are given hexadecimal Unicode escapes; see - /// [`escape_unicode`][escape_unicode]. - /// - /// [escape_unicode]: #method.escape_unicode - /// - /// # Examples - /// - /// As an iterator: - /// - /// ``` - /// for c in '"'.escape_default() { - /// print!("{}", c); - /// } - /// println!(); - /// ``` - /// - /// Using `println!` directly: - /// - /// ``` - /// println!("{}", '"'.escape_default()); - /// ``` - /// - /// - /// Both are equivalent to: - /// - /// ``` - /// println!("\\\""); - /// ``` - /// - /// Using `to_string`: - /// - /// ``` - /// assert_eq!('"'.escape_default().to_string(), "\\\""); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn escape_default(self) -> EscapeDefault { - let init_state = match self { - '\t' => EscapeDefaultState::Backslash('t'), - '\r' => EscapeDefaultState::Backslash('r'), - '\n' => EscapeDefaultState::Backslash('n'), - '\\' | '\'' | '"' => EscapeDefaultState::Backslash(self), - '\x20'..='\x7e' => EscapeDefaultState::Char(self), - _ => EscapeDefaultState::Unicode(self.escape_unicode()), - }; - EscapeDefault { state: init_state } - } - - /// Returns the number of bytes this `char` would need if encoded in UTF-8. - /// - /// That number of bytes is always between 1 and 4, inclusive. - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// let len = 'A'.len_utf8(); - /// assert_eq!(len, 1); - /// - /// let len = 'ß'.len_utf8(); - /// assert_eq!(len, 2); - /// - /// let len = 'ℝ'.len_utf8(); - /// assert_eq!(len, 3); - /// - /// let len = '💣'.len_utf8(); - /// assert_eq!(len, 4); - /// ``` - /// - /// The `&str` type guarantees that its contents are UTF-8, and so we can compare the length it - /// would take if each code point was represented as a `char` vs in the `&str` itself: - /// - /// ``` - /// // as chars - /// let eastern = '東'; - /// let capital = '京'; - /// - /// // both can be represented as three bytes - /// assert_eq!(3, eastern.len_utf8()); - /// assert_eq!(3, capital.len_utf8()); - /// - /// // as a &str, these two are encoded in UTF-8 - /// let tokyo = "東京"; - /// - /// let len = eastern.len_utf8() + capital.len_utf8(); - /// - /// // we can see that they take six bytes total... - /// assert_eq!(6, tokyo.len()); - /// - /// // ... just like the &str - /// assert_eq!(len, tokyo.len()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn len_utf8(self) -> usize { - len_utf8(self as u32) - } - - /// Returns the number of 16-bit code units this `char` would need if - /// encoded in UTF-16. - /// - /// See the documentation for [`len_utf8`] for more explanation of this - /// concept. This function is a mirror, but for UTF-16 instead of UTF-8. - /// - /// [`len_utf8`]: #method.len_utf8 - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// let n = 'ß'.len_utf16(); - /// assert_eq!(n, 1); - /// - /// let len = '💣'.len_utf16(); - /// assert_eq!(len, 2); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn len_utf16(self) -> usize { - let ch = self as u32; - if (ch & 0xFFFF) == ch { 1 } else { 2 } - } - - /// Encodes this character as UTF-8 into the provided byte buffer, - /// and then returns the subslice of the buffer that contains the encoded character. - /// - /// # Panics - /// - /// Panics if the buffer is not large enough. - /// 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, "ß"); - /// - /// assert_eq!(result.len(), 2); - /// ``` - /// - /// A buffer that's too small: - /// - /// ```should_panic - /// let mut b = [0; 1]; - /// - /// // this panics - /// 'ß'.encode_utf8(&mut b); - /// ``` - #[stable(feature = "unicode_encode_char", since = "1.15.0")] - #[inline] - pub fn encode_utf8(self, dst: &mut [u8]) -> &mut str { - // SAFETY: `char` is not a surrogate, so this is valid UTF-8. - unsafe { from_utf8_unchecked_mut(encode_utf8_raw(self as u32, dst)) } - } - - /// Encodes this character as UTF-16 into the provided `u16` buffer, - /// and then returns the subslice of the buffer that contains the encoded character. - /// - /// # Panics - /// - /// Panics if the buffer is not large enough. - /// A buffer of length 2 is large enough to encode any `char`. - /// - /// # Examples - /// - /// In both of these examples, '𝕊' takes two `u16`s to encode. - /// - /// ``` - /// let mut b = [0; 2]; - /// - /// let result = '𝕊'.encode_utf16(&mut b); - /// - /// assert_eq!(result.len(), 2); - /// ``` - /// - /// A buffer that's too small: - /// - /// ```should_panic - /// let mut b = [0; 1]; - /// - /// // this panics - /// '𝕊'.encode_utf16(&mut b); - /// ``` - #[stable(feature = "unicode_encode_char", since = "1.15.0")] - #[inline] - pub fn encode_utf16(self, dst: &mut [u16]) -> &mut [u16] { - encode_utf16_raw(self as u32, dst) - } - - /// Returns `true` if this `char` has the `Alphabetic` property. - /// - /// `Alphabetic` is described in Chapter 4 (Character Properties) of the [Unicode Standard] and - /// specified in the [Unicode Character Database][ucd] [`DerivedCoreProperties.txt`]. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`DerivedCoreProperties.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/DerivedCoreProperties.txt - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!('a'.is_alphabetic()); - /// assert!('京'.is_alphabetic()); - /// - /// let c = '💝'; - /// // love is many things, but it is not alphabetic - /// assert!(!c.is_alphabetic()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_alphabetic(self) -> bool { - match self { - 'a'..='z' | 'A'..='Z' => true, - c => c > '\x7f' && unicode::Alphabetic(c), - } - } - - /// Returns `true` if this `char` has the `Lowercase` property. - /// - /// `Lowercase` is described in Chapter 4 (Character Properties) of the [Unicode Standard] and - /// specified in the [Unicode Character Database][ucd] [`DerivedCoreProperties.txt`]. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`DerivedCoreProperties.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/DerivedCoreProperties.txt - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!('a'.is_lowercase()); - /// assert!('δ'.is_lowercase()); - /// assert!(!'A'.is_lowercase()); - /// assert!(!'Δ'.is_lowercase()); - /// - /// // The various Chinese scripts and punctuation do not have case, and so: - /// assert!(!'中'.is_lowercase()); - /// assert!(!' '.is_lowercase()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_lowercase(self) -> bool { - match self { - 'a'..='z' => true, - c => c > '\x7f' && unicode::Lowercase(c), - } - } - - /// Returns `true` if this `char` has the `Uppercase` property. - /// - /// `Uppercase` is described in Chapter 4 (Character Properties) of the [Unicode Standard] and - /// specified in the [Unicode Character Database][ucd] [`DerivedCoreProperties.txt`]. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`DerivedCoreProperties.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/DerivedCoreProperties.txt - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!(!'a'.is_uppercase()); - /// assert!(!'δ'.is_uppercase()); - /// assert!('A'.is_uppercase()); - /// assert!('Δ'.is_uppercase()); - /// - /// // The various Chinese scripts and punctuation do not have case, and so: - /// assert!(!'中'.is_uppercase()); - /// assert!(!' '.is_uppercase()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_uppercase(self) -> bool { - match self { - 'A'..='Z' => true, - c => c > '\x7f' && unicode::Uppercase(c), - } - } - - /// Returns `true` if this `char` has the `White_Space` property. - /// - /// `White_Space` is specified in the [Unicode Character Database][ucd] [`PropList.txt`]. - /// - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`PropList.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/PropList.txt - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!(' '.is_whitespace()); - /// - /// // a non-breaking space - /// assert!('\u{A0}'.is_whitespace()); - /// - /// assert!(!'越'.is_whitespace()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_whitespace(self) -> bool { - match self { - ' ' | '\x09'..='\x0d' => true, - c => c > '\x7f' && unicode::White_Space(c), - } - } - - /// Returns `true` if this `char` satisfies either [`is_alphabetic()`] or [`is_numeric()`]. - /// - /// [`is_alphabetic()`]: #method.is_alphabetic - /// [`is_numeric()`]: #method.is_numeric - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!('٣'.is_alphanumeric()); - /// assert!('7'.is_alphanumeric()); - /// assert!('৬'.is_alphanumeric()); - /// assert!('¾'.is_alphanumeric()); - /// assert!('①'.is_alphanumeric()); - /// assert!('K'.is_alphanumeric()); - /// assert!('و'.is_alphanumeric()); - /// assert!('藏'.is_alphanumeric()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_alphanumeric(self) -> bool { - self.is_alphabetic() || self.is_numeric() - } - - /// Returns `true` if this `char` has the general category for control codes. - /// - /// Control codes (code points with the general category of `Cc`) are described in Chapter 4 - /// (Character Properties) of the [Unicode Standard] and specified in the [Unicode Character - /// Database][ucd] [`UnicodeData.txt`]. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`UnicodeData.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// // U+009C, STRING TERMINATOR - /// assert!(''.is_control()); - /// assert!(!'q'.is_control()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_control(self) -> bool { - unicode::Cc(self) - } - - /// Returns `true` if this `char` has the `Grapheme_Extend` property. - /// - /// `Grapheme_Extend` is described in [Unicode Standard Annex #29 (Unicode Text - /// Segmentation)][uax29] and specified in the [Unicode Character Database][ucd] - /// [`DerivedCoreProperties.txt`]. - /// - /// [uax29]: https://www.unicode.org/reports/tr29/ - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`DerivedCoreProperties.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/DerivedCoreProperties.txt - #[inline] - pub(crate) fn is_grapheme_extended(self) -> bool { - unicode::Grapheme_Extend(self) - } - - /// Returns `true` if this `char` has one of the general categories for numbers. - /// - /// The general categories for numbers (`Nd` for decimal digits, `Nl` for letter-like numeric - /// characters, and `No` for other numeric characters) are specified in the [Unicode Character - /// Database][ucd] [`UnicodeData.txt`]. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`UnicodeData.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt - /// - /// # Examples - /// - /// Basic usage: - /// - /// ``` - /// assert!('٣'.is_numeric()); - /// assert!('7'.is_numeric()); - /// assert!('৬'.is_numeric()); - /// assert!('¾'.is_numeric()); - /// assert!('①'.is_numeric()); - /// assert!(!'K'.is_numeric()); - /// assert!(!'و'.is_numeric()); - /// assert!(!'藏'.is_numeric()); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn is_numeric(self) -> bool { - match self { - '0'..='9' => true, - c => c > '\x7f' && unicode::N(c), - } - } - - /// Returns an iterator that yields the lowercase mapping of this `char` as one or more - /// `char`s. - /// - /// If this `char` does not have a lowercase mapping, the iterator yields the same `char`. - /// - /// If this `char` has a one-to-one lowercase mapping given by the [Unicode Character - /// Database][ucd] [`UnicodeData.txt`], the iterator yields that `char`. - /// - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`UnicodeData.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt - /// - /// If this `char` requires special considerations (e.g. multiple `char`s) the iterator yields - /// the `char`(s) given by [`SpecialCasing.txt`]. - /// - /// [`SpecialCasing.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/SpecialCasing.txt - /// - /// This operation performs an unconditional mapping without tailoring. That is, the conversion - /// is independent of context and language. - /// - /// In the [Unicode Standard], Chapter 4 (Character Properties) discusses case mapping in - /// general and Chapter 3 (Conformance) discusses the default algorithm for case conversion. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// - /// # Examples - /// - /// As an iterator: - /// - /// ``` - /// for c in 'İ'.to_lowercase() { - /// print!("{}", c); - /// } - /// println!(); - /// ``` - /// - /// Using `println!` directly: - /// - /// ``` - /// println!("{}", 'İ'.to_lowercase()); - /// ``` - /// - /// Both are equivalent to: - /// - /// ``` - /// println!("i\u{307}"); - /// ``` - /// - /// Using `to_string`: - /// - /// ``` - /// assert_eq!('C'.to_lowercase().to_string(), "c"); - /// - /// // Sometimes the result is more than one character: - /// assert_eq!('İ'.to_lowercase().to_string(), "i\u{307}"); - /// - /// // Characters that do not have both uppercase and lowercase - /// // convert into themselves. - /// assert_eq!('山'.to_lowercase().to_string(), "山"); - /// ``` - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn to_lowercase(self) -> ToLowercase { - ToLowercase(CaseMappingIter::new(conversions::to_lower(self))) - } - - /// Returns an iterator that yields the uppercase mapping of this `char` as one or more - /// `char`s. - /// - /// If this `char` does not have a uppercase mapping, the iterator yields the same `char`. - /// - /// If this `char` has a one-to-one uppercase mapping given by the [Unicode Character - /// Database][ucd] [`UnicodeData.txt`], the iterator yields that `char`. - /// - /// [ucd]: https://www.unicode.org/reports/tr44/ - /// [`UnicodeData.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt - /// - /// If this `char` requires special considerations (e.g. multiple `char`s) the iterator yields - /// the `char`(s) given by [`SpecialCasing.txt`]. - /// - /// [`SpecialCasing.txt`]: https://www.unicode.org/Public/UCD/latest/ucd/SpecialCasing.txt - /// - /// This operation performs an unconditional mapping without tailoring. That is, the conversion - /// is independent of context and language. - /// - /// In the [Unicode Standard], Chapter 4 (Character Properties) discusses case mapping in - /// general and Chapter 3 (Conformance) discusses the default algorithm for case conversion. - /// - /// [Unicode Standard]: https://www.unicode.org/versions/latest/ - /// - /// # Examples - /// - /// As an iterator: - /// - /// ``` - /// for c in 'ß'.to_uppercase() { - /// print!("{}", c); - /// } - /// println!(); - /// ``` - /// - /// Using `println!` directly: - /// - /// ``` - /// println!("{}", 'ß'.to_uppercase()); - /// ``` - /// - /// Both are equivalent to: - /// - /// ``` - /// println!("SS"); - /// ``` - /// - /// Using `to_string`: - /// - /// ``` - /// assert_eq!('c'.to_uppercase().to_string(), "C"); - /// - /// // Sometimes the result is more than one character: - /// assert_eq!('ß'.to_uppercase().to_string(), "SS"); - /// - /// // Characters that do not have both uppercase and lowercase - /// // convert into themselves. - /// assert_eq!('山'.to_uppercase().to_string(), "山"); - /// ``` - /// - /// # Note on locale - /// - /// In Turkish, the equivalent of 'i' in Latin has five forms instead of two: - /// - /// * 'Dotless': I / ı, sometimes written ï - /// * 'Dotted': İ / i - /// - /// Note that the lowercase dotted 'i' is the same as the Latin. Therefore: - /// - /// ``` - /// let upper_i = 'i'.to_uppercase().to_string(); - /// ``` - /// - /// The value of `upper_i` here relies on the language of the text: if we're - /// in `en-US`, it should be `"I"`, but if we're in `tr_TR`, it should - /// be `"İ"`. `to_uppercase()` does not take this into account, and so: - /// - /// ``` - /// let upper_i = 'i'.to_uppercase().to_string(); - /// - /// assert_eq!(upper_i, "I"); - /// ``` - /// - /// holds across languages. - #[stable(feature = "rust1", since = "1.0.0")] - #[inline] - pub fn to_uppercase(self) -> ToUppercase { - ToUppercase(CaseMappingIter::new(conversions::to_upper(self))) - } - - /// Checks if the value is within the ASCII range. - /// - /// # Examples - /// - /// ``` - /// let ascii = 'a'; - /// let non_ascii = '❤'; - /// - /// assert!(ascii.is_ascii()); - /// assert!(!non_ascii.is_ascii()); - /// ``` - #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] - #[rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.32.0")] - #[inline] - pub const fn is_ascii(&self) -> bool { - *self as u32 <= 0x7F - } - - /// Makes a copy of the value in its ASCII upper case equivalent. - /// - /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', - /// but non-ASCII letters are unchanged. - /// - /// To uppercase the value in-place, use [`make_ascii_uppercase`]. - /// - /// To uppercase ASCII characters in addition to non-ASCII characters, use - /// [`to_uppercase`]. - /// - /// # Examples - /// - /// ``` - /// let ascii = 'a'; - /// let non_ascii = '❤'; - /// - /// assert_eq!('A', ascii.to_ascii_uppercase()); - /// assert_eq!('❤', non_ascii.to_ascii_uppercase()); - /// ``` - /// - /// [`make_ascii_uppercase`]: #method.make_ascii_uppercase - /// [`to_uppercase`]: #method.to_uppercase - #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] - #[inline] - pub fn to_ascii_uppercase(&self) -> char { - if self.is_ascii() { (*self as u8).to_ascii_uppercase() as char } else { *self } - } - - /// Makes a copy of the value in its ASCII lower case equivalent. - /// - /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', - /// but non-ASCII letters are unchanged. - /// - /// To lowercase the value in-place, use [`make_ascii_lowercase`]. - /// - /// To lowercase ASCII characters in addition to non-ASCII characters, use - /// [`to_lowercase`]. - /// - /// # Examples - /// - /// ``` - /// let ascii = 'A'; - /// let non_ascii = '❤'; - /// - /// assert_eq!('a', ascii.to_ascii_lowercase()); - /// assert_eq!('❤', non_ascii.to_ascii_lowercase()); - /// ``` - /// - /// [`make_ascii_lowercase`]: #method.make_ascii_lowercase - /// [`to_lowercase`]: #method.to_lowercase - #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] - #[inline] - pub fn to_ascii_lowercase(&self) -> char { - if self.is_ascii() { (*self as u8).to_ascii_lowercase() as char } else { *self } - } - - /// Checks that two values are an ASCII case-insensitive match. - /// - /// Equivalent to `to_ascii_lowercase(a) == to_ascii_lowercase(b)`. - /// - /// # Examples - /// - /// ``` - /// let upper_a = 'A'; - /// let lower_a = 'a'; - /// let lower_z = 'z'; - /// - /// assert!(upper_a.eq_ignore_ascii_case(&lower_a)); - /// assert!(upper_a.eq_ignore_ascii_case(&upper_a)); - /// assert!(!upper_a.eq_ignore_ascii_case(&lower_z)); - /// ``` - #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] - #[inline] - pub fn eq_ignore_ascii_case(&self, other: &char) -> bool { - self.to_ascii_lowercase() == other.to_ascii_lowercase() - } - - /// Converts this type to its ASCII upper case equivalent in-place. - /// - /// ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', - /// but non-ASCII letters are unchanged. - /// - /// To return a new uppercased value without modifying the existing one, use - /// [`to_ascii_uppercase`]. - /// - /// # Examples - /// - /// ``` - /// let mut ascii = 'a'; - /// - /// ascii.make_ascii_uppercase(); - /// - /// assert_eq!('A', ascii); - /// ``` - /// - /// [`to_ascii_uppercase`]: #method.to_ascii_uppercase - #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] - #[inline] - pub fn make_ascii_uppercase(&mut self) { - *self = self.to_ascii_uppercase(); - } - - /// Converts this type to its ASCII lower case equivalent in-place. - /// - /// ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', - /// but non-ASCII letters are unchanged. - /// - /// To return a new lowercased value without modifying the existing one, use - /// [`to_ascii_lowercase`]. - /// - /// # Examples - /// - /// ``` - /// let mut ascii = 'A'; - /// - /// ascii.make_ascii_lowercase(); - /// - /// assert_eq!('a', ascii); - /// ``` - /// - /// [`to_ascii_lowercase`]: #method.to_ascii_lowercase - #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] - #[inline] - pub fn make_ascii_lowercase(&mut self) { - *self = self.to_ascii_lowercase(); - } - - /// Checks if the value is an ASCII alphabetic character: - /// - /// - U+0041 'A' ..= U+005A 'Z', or - /// - U+0061 'a' ..= U+007A 'z'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(uppercase_a.is_ascii_alphabetic()); - /// assert!(uppercase_g.is_ascii_alphabetic()); - /// assert!(a.is_ascii_alphabetic()); - /// assert!(g.is_ascii_alphabetic()); - /// assert!(!zero.is_ascii_alphabetic()); - /// assert!(!percent.is_ascii_alphabetic()); - /// assert!(!space.is_ascii_alphabetic()); - /// assert!(!lf.is_ascii_alphabetic()); - /// assert!(!esc.is_ascii_alphabetic()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_alphabetic(&self) -> bool { - match *self { - 'A'..='Z' | 'a'..='z' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII uppercase character: - /// U+0041 'A' ..= U+005A 'Z'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(uppercase_a.is_ascii_uppercase()); - /// assert!(uppercase_g.is_ascii_uppercase()); - /// assert!(!a.is_ascii_uppercase()); - /// assert!(!g.is_ascii_uppercase()); - /// assert!(!zero.is_ascii_uppercase()); - /// assert!(!percent.is_ascii_uppercase()); - /// assert!(!space.is_ascii_uppercase()); - /// assert!(!lf.is_ascii_uppercase()); - /// assert!(!esc.is_ascii_uppercase()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_uppercase(&self) -> bool { - match *self { - 'A'..='Z' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII lowercase character: - /// U+0061 'a' ..= U+007A 'z'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(!uppercase_a.is_ascii_lowercase()); - /// assert!(!uppercase_g.is_ascii_lowercase()); - /// assert!(a.is_ascii_lowercase()); - /// assert!(g.is_ascii_lowercase()); - /// assert!(!zero.is_ascii_lowercase()); - /// assert!(!percent.is_ascii_lowercase()); - /// assert!(!space.is_ascii_lowercase()); - /// assert!(!lf.is_ascii_lowercase()); - /// assert!(!esc.is_ascii_lowercase()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_lowercase(&self) -> bool { - match *self { - 'a'..='z' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII alphanumeric character: - /// - /// - U+0041 'A' ..= U+005A 'Z', or - /// - U+0061 'a' ..= U+007A 'z', or - /// - U+0030 '0' ..= U+0039 '9'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(uppercase_a.is_ascii_alphanumeric()); - /// assert!(uppercase_g.is_ascii_alphanumeric()); - /// assert!(a.is_ascii_alphanumeric()); - /// assert!(g.is_ascii_alphanumeric()); - /// assert!(zero.is_ascii_alphanumeric()); - /// assert!(!percent.is_ascii_alphanumeric()); - /// assert!(!space.is_ascii_alphanumeric()); - /// assert!(!lf.is_ascii_alphanumeric()); - /// assert!(!esc.is_ascii_alphanumeric()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_alphanumeric(&self) -> bool { - match *self { - '0'..='9' | 'A'..='Z' | 'a'..='z' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII decimal digit: - /// U+0030 '0' ..= U+0039 '9'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(!uppercase_a.is_ascii_digit()); - /// assert!(!uppercase_g.is_ascii_digit()); - /// assert!(!a.is_ascii_digit()); - /// assert!(!g.is_ascii_digit()); - /// assert!(zero.is_ascii_digit()); - /// assert!(!percent.is_ascii_digit()); - /// assert!(!space.is_ascii_digit()); - /// assert!(!lf.is_ascii_digit()); - /// assert!(!esc.is_ascii_digit()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_digit(&self) -> bool { - match *self { - '0'..='9' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII hexadecimal digit: - /// - /// - U+0030 '0' ..= U+0039 '9', or - /// - U+0041 'A' ..= U+0046 'F', or - /// - U+0061 'a' ..= U+0066 'f'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(uppercase_a.is_ascii_hexdigit()); - /// assert!(!uppercase_g.is_ascii_hexdigit()); - /// assert!(a.is_ascii_hexdigit()); - /// assert!(!g.is_ascii_hexdigit()); - /// assert!(zero.is_ascii_hexdigit()); - /// assert!(!percent.is_ascii_hexdigit()); - /// assert!(!space.is_ascii_hexdigit()); - /// assert!(!lf.is_ascii_hexdigit()); - /// assert!(!esc.is_ascii_hexdigit()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_hexdigit(&self) -> bool { - match *self { - '0'..='9' | 'A'..='F' | 'a'..='f' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII punctuation character: - /// - /// - U+0021 ..= U+002F `! " # $ % & ' ( ) * + , - . /`, or - /// - U+003A ..= U+0040 `: ; < = > ? @`, or - /// - U+005B ..= U+0060 ``[ \ ] ^ _ ` ``, or - /// - U+007B ..= U+007E `{ | } ~` - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(!uppercase_a.is_ascii_punctuation()); - /// assert!(!uppercase_g.is_ascii_punctuation()); - /// assert!(!a.is_ascii_punctuation()); - /// assert!(!g.is_ascii_punctuation()); - /// assert!(!zero.is_ascii_punctuation()); - /// assert!(percent.is_ascii_punctuation()); - /// assert!(!space.is_ascii_punctuation()); - /// assert!(!lf.is_ascii_punctuation()); - /// assert!(!esc.is_ascii_punctuation()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_punctuation(&self) -> bool { - match *self { - '!'..='/' | ':'..='@' | '['..='`' | '{'..='~' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII graphic character: - /// U+0021 '!' ..= U+007E '~'. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(uppercase_a.is_ascii_graphic()); - /// assert!(uppercase_g.is_ascii_graphic()); - /// assert!(a.is_ascii_graphic()); - /// assert!(g.is_ascii_graphic()); - /// assert!(zero.is_ascii_graphic()); - /// assert!(percent.is_ascii_graphic()); - /// assert!(!space.is_ascii_graphic()); - /// assert!(!lf.is_ascii_graphic()); - /// assert!(!esc.is_ascii_graphic()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_graphic(&self) -> bool { - match *self { - '!'..='~' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII whitespace character: - /// U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED, - /// U+000C FORM FEED, or U+000D CARRIAGE RETURN. - /// - /// Rust uses the WhatWG Infra Standard's [definition of ASCII - /// whitespace][infra-aw]. There are several other definitions in - /// wide use. For instance, [the POSIX locale][pct] includes - /// U+000B VERTICAL TAB as well as all the above characters, - /// but—from the very same specification—[the default rule for - /// "field splitting" in the Bourne shell][bfs] considers *only* - /// SPACE, HORIZONTAL TAB, and LINE FEED as whitespace. - /// - /// If you are writing a program that will process an existing - /// file format, check what that format's definition of whitespace is - /// before using this function. - /// - /// [infra-aw]: https://infra.spec.whatwg.org/#ascii-whitespace - /// [pct]: http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap07.html#tag_07_03_01 - /// [bfs]: http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_05 - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(!uppercase_a.is_ascii_whitespace()); - /// assert!(!uppercase_g.is_ascii_whitespace()); - /// assert!(!a.is_ascii_whitespace()); - /// assert!(!g.is_ascii_whitespace()); - /// assert!(!zero.is_ascii_whitespace()); - /// assert!(!percent.is_ascii_whitespace()); - /// assert!(space.is_ascii_whitespace()); - /// assert!(lf.is_ascii_whitespace()); - /// assert!(!esc.is_ascii_whitespace()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_whitespace(&self) -> bool { - match *self { - '\t' | '\n' | '\x0C' | '\r' | ' ' => true, - _ => false, - } - } - - /// Checks if the value is an ASCII control character: - /// U+0000 NUL ..= U+001F UNIT SEPARATOR, or U+007F DELETE. - /// Note that most ASCII whitespace characters are control - /// characters, but SPACE is not. - /// - /// # Examples - /// - /// ``` - /// let uppercase_a = 'A'; - /// let uppercase_g = 'G'; - /// let a = 'a'; - /// let g = 'g'; - /// let zero = '0'; - /// let percent = '%'; - /// let space = ' '; - /// let lf = '\n'; - /// let esc: char = 0x1b_u8.into(); - /// - /// assert!(!uppercase_a.is_ascii_control()); - /// assert!(!uppercase_g.is_ascii_control()); - /// assert!(!a.is_ascii_control()); - /// assert!(!g.is_ascii_control()); - /// assert!(!zero.is_ascii_control()); - /// assert!(!percent.is_ascii_control()); - /// assert!(!space.is_ascii_control()); - /// assert!(lf.is_ascii_control()); - /// assert!(esc.is_ascii_control()); - /// ``` - #[stable(feature = "ascii_ctype_on_intrinsics", since = "1.24.0")] - #[rustc_const_stable(feature = "const_ascii_ctype_on_intrinsics", since = "1.47.0")] - #[inline] - pub const fn is_ascii_control(&self) -> bool { - match *self { - '\0'..='\x1F' | '\x7F' => true, - _ => false, - } - } -} - -#[inline] -fn len_utf8(code: u32) -> usize { - if code < MAX_ONE_B { - 1 - } else if code < MAX_TWO_B { - 2 - } else if code < MAX_THREE_B { - 3 - } else { - 4 - } -} - -/// Encodes a raw u32 value as UTF-8 into the provided byte buffer, -/// and then returns the subslice of the buffer that contains the encoded character. -/// -/// Unlike `char::encode_utf8`, this method also handles codepoints in the surrogate range. -/// (Creating a `char` in the surrogate range is UB.) -/// The result is valid [generalized UTF-8] but not valid UTF-8. -/// -/// [generalized UTF-8]: https://simonsapin.github.io/wtf-8/#generalized-utf8 -/// -/// # Panics -/// -/// Panics if the buffer is not large enough. -/// A buffer of length four is large enough to encode any `char`. -#[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")] -#[doc(hidden)] -#[inline] -pub fn encode_utf8_raw(code: u32, dst: &mut [u8]) -> &mut [u8] { - let len = len_utf8(code); - match (len, &mut dst[..]) { - (1, [a, ..]) => { - *a = code as u8; - } - (2, [a, b, ..]) => { - *a = (code >> 6 & 0x1F) as u8 | TAG_TWO_B; - *b = (code & 0x3F) as u8 | TAG_CONT; - } - (3, [a, b, c, ..]) => { - *a = (code >> 12 & 0x0F) as u8 | TAG_THREE_B; - *b = (code >> 6 & 0x3F) as u8 | TAG_CONT; - *c = (code & 0x3F) as u8 | TAG_CONT; - } - (4, [a, b, c, d, ..]) => { - *a = (code >> 18 & 0x07) as u8 | TAG_FOUR_B; - *b = (code >> 12 & 0x3F) as u8 | TAG_CONT; - *c = (code >> 6 & 0x3F) as u8 | TAG_CONT; - *d = (code & 0x3F) as u8 | TAG_CONT; - } - _ => panic!( - "encode_utf8: need {} bytes to encode U+{:X}, but the buffer has {}", - len, - code, - dst.len(), - ), - }; - &mut dst[..len] -} - -/// Encodes a raw u32 value as UTF-16 into the provided `u16` buffer, -/// and then returns the subslice of the buffer that contains the encoded character. -/// -/// Unlike `char::encode_utf16`, this method also handles codepoints in the surrogate range. -/// (Creating a `char` in the surrogate range is UB.) -/// -/// # Panics -/// -/// Panics if the buffer is not large enough. -/// A buffer of length 2 is large enough to encode any `char`. -#[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")] -#[doc(hidden)] -#[inline] -pub fn encode_utf16_raw(mut code: u32, dst: &mut [u16]) -> &mut [u16] { - // SAFETY: each arm checks whether there are enough bits to write into - unsafe { - if (code & 0xFFFF) == code && !dst.is_empty() { - // The BMP falls through - *dst.get_unchecked_mut(0) = code as u16; - slice::from_raw_parts_mut(dst.as_mut_ptr(), 1) - } else if dst.len() >= 2 { - // Supplementary planes break into surrogates. - code -= 0x1_0000; - *dst.get_unchecked_mut(0) = 0xD800 | ((code >> 10) as u16); - *dst.get_unchecked_mut(1) = 0xDC00 | ((code as u16) & 0x3FF); - slice::from_raw_parts_mut(dst.as_mut_ptr(), 2) - } else { - panic!( - "encode_utf16: need {} units to encode U+{:X}, but the buffer has {}", - from_u32_unchecked(code).len_utf16(), - code, - dst.len(), - ) - } - } -} |