| //! String manipulation |
| //! |
| //! For more details, see std::str |
| |
| #![stable(feature = "rust1", since = "1.0.0")] |
| |
| use self::pattern::Pattern; |
| use self::pattern::{Searcher, ReverseSearcher, DoubleEndedSearcher}; |
| |
| use char; |
| use fmt; |
| use iter::{Map, Cloned, FusedIterator, TrustedLen, Filter}; |
| use iter_private::TrustedRandomAccess; |
| use slice::{self, SliceIndex, Split as SliceSplit}; |
| use mem; |
| |
| pub mod pattern; |
| |
| #[unstable(feature = "str_internals", issue = "0")] |
| #[allow(missing_docs)] |
| pub mod lossy; |
| |
| /// Parse a value from a string |
| /// |
| /// `FromStr`'s [`from_str`] method is often used implicitly, through |
| /// [`str`]'s [`parse`] method. See [`parse`]'s documentation for examples. |
| /// |
| /// [`from_str`]: #tymethod.from_str |
| /// [`str`]: ../../std/primitive.str.html |
| /// [`parse`]: ../../std/primitive.str.html#method.parse |
| /// |
| /// `FromStr` does not have a lifetime parameter, and so you can only parse types |
| /// that do not contain a lifetime parameter themselves. In other words, you can |
| /// parse an `i32` with `FromStr`, but not a `&i32`. You can parse a struct that |
| /// contains an `i32`, but not one that contains an `&i32`. |
| /// |
| /// # Examples |
| /// |
| /// Basic implementation of `FromStr` on an example `Point` type: |
| /// |
| /// ``` |
| /// use std::str::FromStr; |
| /// use std::num::ParseIntError; |
| /// |
| /// #[derive(Debug, PartialEq)] |
| /// struct Point { |
| /// x: i32, |
| /// y: i32 |
| /// } |
| /// |
| /// impl FromStr for Point { |
| /// type Err = ParseIntError; |
| /// |
| /// fn from_str(s: &str) -> Result<Self, Self::Err> { |
| /// let coords: Vec<&str> = s.trim_matches(|p| p == '(' || p == ')' ) |
| /// .split(',') |
| /// .collect(); |
| /// |
| /// let x_fromstr = coords[0].parse::<i32>()?; |
| /// let y_fromstr = coords[1].parse::<i32>()?; |
| /// |
| /// Ok(Point { x: x_fromstr, y: y_fromstr }) |
| /// } |
| /// } |
| /// |
| /// let p = Point::from_str("(1,2)"); |
| /// assert_eq!(p.unwrap(), Point{ x: 1, y: 2} ) |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub trait FromStr: Sized { |
| /// The associated error which can be returned from parsing. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| type Err; |
| |
| /// Parses a string `s` to return a value of this type. |
| /// |
| /// If parsing succeeds, return the value inside [`Ok`], otherwise |
| /// when the string is ill-formatted return an error specific to the |
| /// inside [`Err`]. The error type is specific to implementation of the trait. |
| /// |
| /// [`Ok`]: ../../std/result/enum.Result.html#variant.Ok |
| /// [`Err`]: ../../std/result/enum.Result.html#variant.Err |
| /// |
| /// # Examples |
| /// |
| /// Basic usage with [`i32`][ithirtytwo], a type that implements `FromStr`: |
| /// |
| /// [ithirtytwo]: ../../std/primitive.i32.html |
| /// |
| /// ``` |
| /// use std::str::FromStr; |
| /// |
| /// let s = "5"; |
| /// let x = i32::from_str(s).unwrap(); |
| /// |
| /// assert_eq!(5, x); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| fn from_str(s: &str) -> Result<Self, Self::Err>; |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl FromStr for bool { |
| type Err = ParseBoolError; |
| |
| /// Parse a `bool` from a string. |
| /// |
| /// Yields a `Result<bool, ParseBoolError>`, because `s` may or may not |
| /// actually be parseable. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::str::FromStr; |
| /// |
| /// assert_eq!(FromStr::from_str("true"), Ok(true)); |
| /// assert_eq!(FromStr::from_str("false"), Ok(false)); |
| /// assert!(<bool as FromStr>::from_str("not even a boolean").is_err()); |
| /// ``` |
| /// |
| /// Note, in many cases, the `.parse()` method on `str` is more proper. |
| /// |
| /// ``` |
| /// assert_eq!("true".parse(), Ok(true)); |
| /// assert_eq!("false".parse(), Ok(false)); |
| /// assert!("not even a boolean".parse::<bool>().is_err()); |
| /// ``` |
| #[inline] |
| fn from_str(s: &str) -> Result<bool, ParseBoolError> { |
| match s { |
| "true" => Ok(true), |
| "false" => Ok(false), |
| _ => Err(ParseBoolError { _priv: () }), |
| } |
| } |
| } |
| |
| /// An error returned when parsing a `bool` using [`from_str`] fails |
| /// |
| /// [`from_str`]: ../../std/primitive.bool.html#method.from_str |
| #[derive(Debug, Clone, PartialEq, Eq)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct ParseBoolError { _priv: () } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl fmt::Display for ParseBoolError { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| "provided string was not `true` or `false`".fmt(f) |
| } |
| } |
| |
| /* |
| Section: Creating a string |
| */ |
| |
| /// Errors which can occur when attempting to interpret a sequence of [`u8`] |
| /// as a string. |
| /// |
| /// [`u8`]: ../../std/primitive.u8.html |
| /// |
| /// As such, the `from_utf8` family of functions and methods for both [`String`]s |
| /// and [`&str`]s make use of this error, for example. |
| /// |
| /// [`String`]: ../../std/string/struct.String.html#method.from_utf8 |
| /// [`&str`]: ../../std/str/fn.from_utf8.html |
| /// |
| /// # Examples |
| /// |
| /// This error type’s methods can be used to create functionality |
| /// similar to `String::from_utf8_lossy` without allocating heap memory: |
| /// |
| /// ``` |
| /// fn from_utf8_lossy<F>(mut input: &[u8], mut push: F) where F: FnMut(&str) { |
| /// loop { |
| /// match ::std::str::from_utf8(input) { |
| /// Ok(valid) => { |
| /// push(valid); |
| /// break |
| /// } |
| /// Err(error) => { |
| /// let (valid, after_valid) = input.split_at(error.valid_up_to()); |
| /// unsafe { |
| /// push(::std::str::from_utf8_unchecked(valid)) |
| /// } |
| /// push("\u{FFFD}"); |
| /// |
| /// if let Some(invalid_sequence_length) = error.error_len() { |
| /// input = &after_valid[invalid_sequence_length..] |
| /// } else { |
| /// break |
| /// } |
| /// } |
| /// } |
| /// } |
| /// } |
| /// ``` |
| #[derive(Copy, Eq, PartialEq, Clone, Debug)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Utf8Error { |
| valid_up_to: usize, |
| error_len: Option<u8>, |
| } |
| |
| impl Utf8Error { |
| /// Returns the index in the given string up to which valid UTF-8 was |
| /// verified. |
| /// |
| /// It is the maximum index such that `from_utf8(&input[..index])` |
| /// would return `Ok(_)`. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // some invalid bytes, in a vector |
| /// let sparkle_heart = vec![0, 159, 146, 150]; |
| /// |
| /// // std::str::from_utf8 returns a Utf8Error |
| /// let error = str::from_utf8(&sparkle_heart).unwrap_err(); |
| /// |
| /// // the second byte is invalid here |
| /// assert_eq!(1, error.valid_up_to()); |
| /// ``` |
| #[stable(feature = "utf8_error", since = "1.5.0")] |
| pub fn valid_up_to(&self) -> usize { self.valid_up_to } |
| |
| /// Provide more information about the failure: |
| /// |
| /// * `None`: the end of the input was reached unexpectedly. |
| /// `self.valid_up_to()` is 1 to 3 bytes from the end of the input. |
| /// If a byte stream (such as a file or a network socket) is being decoded incrementally, |
| /// this could be a valid `char` whose UTF-8 byte sequence is spanning multiple chunks. |
| /// |
| /// * `Some(len)`: an unexpected byte was encountered. |
| /// The length provided is that of the invalid byte sequence |
| /// that starts at the index given by `valid_up_to()`. |
| /// Decoding should resume after that sequence |
| /// (after inserting a [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD]) in case of |
| /// lossy decoding. |
| /// |
| /// [U+FFFD]: ../../std/char/constant.REPLACEMENT_CHARACTER.html |
| #[stable(feature = "utf8_error_error_len", since = "1.20.0")] |
| pub fn error_len(&self) -> Option<usize> { |
| self.error_len.map(|len| len as usize) |
| } |
| } |
| |
| /// Converts a slice of bytes to a string slice. |
| /// |
| /// A string slice ([`&str`]) is made of bytes ([`u8`]), and a byte slice |
| /// ([`&[u8]`][byteslice]) is made of bytes, so this function converts between |
| /// the two. Not all byte slices are valid string slices, however: [`&str`] requires |
| /// that it is valid UTF-8. `from_utf8()` checks to ensure that the bytes are valid |
| /// UTF-8, and then does the conversion. |
| /// |
| /// [`&str`]: ../../std/primitive.str.html |
| /// [`u8`]: ../../std/primitive.u8.html |
| /// [byteslice]: ../../std/primitive.slice.html |
| /// |
| /// If you are sure that the byte slice is valid UTF-8, and you don't want to |
| /// incur the overhead of the validity check, there is an unsafe version of |
| /// this function, [`from_utf8_unchecked`][fromutf8u], which has the same |
| /// behavior but skips the check. |
| /// |
| /// [fromutf8u]: fn.from_utf8_unchecked.html |
| /// |
| /// If you need a `String` instead of a `&str`, consider |
| /// [`String::from_utf8`][string]. |
| /// |
| /// [string]: ../../std/string/struct.String.html#method.from_utf8 |
| /// |
| /// Because you can stack-allocate a `[u8; N]`, and you can take a |
| /// [`&[u8]`][byteslice] of it, this function is one way to have a |
| /// stack-allocated string. There is an example of this in the |
| /// examples section below. |
| /// |
| /// [byteslice]: ../../std/primitive.slice.html |
| /// |
| /// # Errors |
| /// |
| /// Returns `Err` if the slice is not UTF-8 with a description as to why the |
| /// provided slice is not UTF-8. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // some bytes, in a vector |
| /// let sparkle_heart = vec![240, 159, 146, 150]; |
| /// |
| /// // We know these bytes are valid, so just use `unwrap()`. |
| /// let sparkle_heart = str::from_utf8(&sparkle_heart).unwrap(); |
| /// |
| /// assert_eq!("💖", sparkle_heart); |
| /// ``` |
| /// |
| /// Incorrect bytes: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // some invalid bytes, in a vector |
| /// let sparkle_heart = vec![0, 159, 146, 150]; |
| /// |
| /// assert!(str::from_utf8(&sparkle_heart).is_err()); |
| /// ``` |
| /// |
| /// See the docs for [`Utf8Error`][error] for more details on the kinds of |
| /// errors that can be returned. |
| /// |
| /// [error]: struct.Utf8Error.html |
| /// |
| /// A "stack allocated string": |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // some bytes, in a stack-allocated array |
| /// let sparkle_heart = [240, 159, 146, 150]; |
| /// |
| /// // We know these bytes are valid, so just use `unwrap()`. |
| /// let sparkle_heart = str::from_utf8(&sparkle_heart).unwrap(); |
| /// |
| /// assert_eq!("💖", sparkle_heart); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn from_utf8(v: &[u8]) -> Result<&str, Utf8Error> { |
| run_utf8_validation(v)?; |
| Ok(unsafe { from_utf8_unchecked(v) }) |
| } |
| |
| /// Converts a mutable slice of bytes to a mutable string slice. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // "Hello, Rust!" as a mutable vector |
| /// let mut hellorust = vec![72, 101, 108, 108, 111, 44, 32, 82, 117, 115, 116, 33]; |
| /// |
| /// // As we know these bytes are valid, we can use `unwrap()` |
| /// let outstr = str::from_utf8_mut(&mut hellorust).unwrap(); |
| /// |
| /// assert_eq!("Hello, Rust!", outstr); |
| /// ``` |
| /// |
| /// Incorrect bytes: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // Some invalid bytes in a mutable vector |
| /// let mut invalid = vec![128, 223]; |
| /// |
| /// assert!(str::from_utf8_mut(&mut invalid).is_err()); |
| /// ``` |
| /// See the docs for [`Utf8Error`][error] for more details on the kinds of |
| /// errors that can be returned. |
| /// |
| /// [error]: struct.Utf8Error.html |
| #[stable(feature = "str_mut_extras", since = "1.20.0")] |
| pub fn from_utf8_mut(v: &mut [u8]) -> Result<&mut str, Utf8Error> { |
| run_utf8_validation(v)?; |
| Ok(unsafe { from_utf8_unchecked_mut(v) }) |
| } |
| |
| /// Converts a slice of bytes to a string slice without checking |
| /// that the string contains valid UTF-8. |
| /// |
| /// See the safe version, [`from_utf8`][fromutf8], for more information. |
| /// |
| /// [fromutf8]: fn.from_utf8.html |
| /// |
| /// # Safety |
| /// |
| /// This function is unsafe because it does not check that the bytes passed to |
| /// it are valid UTF-8. If this constraint is violated, undefined behavior |
| /// results, as the rest of Rust assumes that [`&str`]s are valid UTF-8. |
| /// |
| /// [`&str`]: ../../std/primitive.str.html |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// // some bytes, in a vector |
| /// let sparkle_heart = vec![240, 159, 146, 150]; |
| /// |
| /// let sparkle_heart = unsafe { |
| /// str::from_utf8_unchecked(&sparkle_heart) |
| /// }; |
| /// |
| /// assert_eq!("💖", sparkle_heart); |
| /// ``` |
| #[inline] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub unsafe fn from_utf8_unchecked(v: &[u8]) -> &str { |
| &*(v as *const [u8] as *const str) |
| } |
| |
| /// Converts a slice of bytes to a string slice without checking |
| /// that the string contains valid UTF-8; mutable version. |
| /// |
| /// See the immutable version, [`from_utf8_unchecked()`][fromutf8], for more information. |
| /// |
| /// [fromutf8]: fn.from_utf8_unchecked.html |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// use std::str; |
| /// |
| /// let mut heart = vec![240, 159, 146, 150]; |
| /// let heart = unsafe { str::from_utf8_unchecked_mut(&mut heart) }; |
| /// |
| /// assert_eq!("💖", heart); |
| /// ``` |
| #[inline] |
| #[stable(feature = "str_mut_extras", since = "1.20.0")] |
| pub unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str { |
| &mut *(v as *mut [u8] as *mut str) |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl fmt::Display for Utf8Error { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| if let Some(error_len) = self.error_len { |
| write!(f, "invalid utf-8 sequence of {} bytes from index {}", |
| error_len, self.valid_up_to) |
| } else { |
| write!(f, "incomplete utf-8 byte sequence from index {}", self.valid_up_to) |
| } |
| } |
| } |
| |
| /* |
| Section: Iterators |
| */ |
| |
| /// An iterator over the [`char`]s of a string slice. |
| /// |
| /// [`char`]: ../../std/primitive.char.html |
| /// |
| /// This struct is created by the [`chars`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`chars`]: ../../std/primitive.str.html#method.chars |
| /// [`str`]: ../../std/primitive.str.html |
| #[derive(Clone, Debug)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Chars<'a> { |
| iter: slice::Iter<'a, u8> |
| } |
| |
| /// Returns the initial codepoint accumulator for the first byte. |
| /// The first byte is special, only want bottom 5 bits for width 2, 4 bits |
| /// for width 3, and 3 bits for width 4. |
| #[inline] |
| fn utf8_first_byte(byte: u8, width: u32) -> u32 { (byte & (0x7F >> width)) as u32 } |
| |
| /// Returns the value of `ch` updated with continuation byte `byte`. |
| #[inline] |
| fn utf8_acc_cont_byte(ch: u32, byte: u8) -> u32 { (ch << 6) | (byte & CONT_MASK) as u32 } |
| |
| /// Checks whether the byte is a UTF-8 continuation byte (i.e., starts with the |
| /// bits `10`). |
| #[inline] |
| fn utf8_is_cont_byte(byte: u8) -> bool { (byte & !CONT_MASK) == TAG_CONT_U8 } |
| |
| #[inline] |
| fn unwrap_or_0(opt: Option<&u8>) -> u8 { |
| match opt { |
| Some(&byte) => byte, |
| None => 0, |
| } |
| } |
| |
| /// Reads the next code point out of a byte iterator (assuming a |
| /// UTF-8-like encoding). |
| #[unstable(feature = "str_internals", issue = "0")] |
| #[inline] |
| pub fn next_code_point<'a, I: Iterator<Item = &'a u8>>(bytes: &mut I) -> Option<u32> { |
| // Decode UTF-8 |
| let x = *bytes.next()?; |
| if x < 128 { |
| return Some(x as u32) |
| } |
| |
| // Multibyte case follows |
| // Decode from a byte combination out of: [[[x y] z] w] |
| // NOTE: Performance is sensitive to the exact formulation here |
| let init = utf8_first_byte(x, 2); |
| let y = unwrap_or_0(bytes.next()); |
| let mut ch = utf8_acc_cont_byte(init, y); |
| if x >= 0xE0 { |
| // [[x y z] w] case |
| // 5th bit in 0xE0 .. 0xEF is always clear, so `init` is still valid |
| let z = unwrap_or_0(bytes.next()); |
| let y_z = utf8_acc_cont_byte((y & CONT_MASK) as u32, z); |
| ch = init << 12 | y_z; |
| if x >= 0xF0 { |
| // [x y z w] case |
| // use only the lower 3 bits of `init` |
| let w = unwrap_or_0(bytes.next()); |
| ch = (init & 7) << 18 | utf8_acc_cont_byte(y_z, w); |
| } |
| } |
| |
| Some(ch) |
| } |
| |
| /// Reads the last code point out of a byte iterator (assuming a |
| /// UTF-8-like encoding). |
| #[inline] |
| fn next_code_point_reverse<'a, I>(bytes: &mut I) -> Option<u32> |
| where I: DoubleEndedIterator<Item = &'a u8>, |
| { |
| // Decode UTF-8 |
| let w = match *bytes.next_back()? { |
| next_byte if next_byte < 128 => return Some(next_byte as u32), |
| back_byte => back_byte, |
| }; |
| |
| // Multibyte case follows |
| // Decode from a byte combination out of: [x [y [z w]]] |
| let mut ch; |
| let z = unwrap_or_0(bytes.next_back()); |
| ch = utf8_first_byte(z, 2); |
| if utf8_is_cont_byte(z) { |
| let y = unwrap_or_0(bytes.next_back()); |
| ch = utf8_first_byte(y, 3); |
| if utf8_is_cont_byte(y) { |
| let x = unwrap_or_0(bytes.next_back()); |
| ch = utf8_first_byte(x, 4); |
| ch = utf8_acc_cont_byte(ch, y); |
| } |
| ch = utf8_acc_cont_byte(ch, z); |
| } |
| ch = utf8_acc_cont_byte(ch, w); |
| |
| Some(ch) |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> Iterator for Chars<'a> { |
| type Item = char; |
| |
| #[inline] |
| fn next(&mut self) -> Option<char> { |
| next_code_point(&mut self.iter).map(|ch| { |
| // str invariant says `ch` is a valid Unicode Scalar Value |
| unsafe { |
| char::from_u32_unchecked(ch) |
| } |
| }) |
| } |
| |
| #[inline] |
| fn count(self) -> usize { |
| // length in `char` is equal to the number of non-continuation bytes |
| let bytes_len = self.iter.len(); |
| let mut cont_bytes = 0; |
| for &byte in self.iter { |
| cont_bytes += utf8_is_cont_byte(byte) as usize; |
| } |
| bytes_len - cont_bytes |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let len = self.iter.len(); |
| // `(len + 3)` can't overflow, because we know that the `slice::Iter` |
| // belongs to a slice in memory which has a maximum length of |
| // `isize::MAX` (that's well below `usize::MAX`). |
| ((len + 3) / 4, Some(len)) |
| } |
| |
| #[inline] |
| fn last(mut self) -> Option<char> { |
| // No need to go through the entire string. |
| self.next_back() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> DoubleEndedIterator for Chars<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<char> { |
| next_code_point_reverse(&mut self.iter).map(|ch| { |
| // str invariant says `ch` is a valid Unicode Scalar Value |
| unsafe { |
| char::from_u32_unchecked(ch) |
| } |
| }) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl FusedIterator for Chars<'_> {} |
| |
| impl<'a> Chars<'a> { |
| /// View the underlying data as a subslice of the original data. |
| /// |
| /// This has the same lifetime as the original slice, and so the |
| /// iterator can continue to be used while this exists. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let mut chars = "abc".chars(); |
| /// |
| /// assert_eq!(chars.as_str(), "abc"); |
| /// chars.next(); |
| /// assert_eq!(chars.as_str(), "bc"); |
| /// chars.next(); |
| /// chars.next(); |
| /// assert_eq!(chars.as_str(), ""); |
| /// ``` |
| #[stable(feature = "iter_to_slice", since = "1.4.0")] |
| #[inline] |
| pub fn as_str(&self) -> &'a str { |
| unsafe { from_utf8_unchecked(self.iter.as_slice()) } |
| } |
| } |
| |
| /// An iterator over the [`char`]s of a string slice, and their positions. |
| /// |
| /// [`char`]: ../../std/primitive.char.html |
| /// |
| /// This struct is created by the [`char_indices`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`char_indices`]: ../../std/primitive.str.html#method.char_indices |
| /// [`str`]: ../../std/primitive.str.html |
| #[derive(Clone, Debug)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct CharIndices<'a> { |
| front_offset: usize, |
| iter: Chars<'a>, |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> Iterator for CharIndices<'a> { |
| type Item = (usize, char); |
| |
| #[inline] |
| fn next(&mut self) -> Option<(usize, char)> { |
| let pre_len = self.iter.iter.len(); |
| match self.iter.next() { |
| None => None, |
| Some(ch) => { |
| let index = self.front_offset; |
| let len = self.iter.iter.len(); |
| self.front_offset += pre_len - len; |
| Some((index, ch)) |
| } |
| } |
| } |
| |
| #[inline] |
| fn count(self) -> usize { |
| self.iter.count() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| |
| #[inline] |
| fn last(mut self) -> Option<(usize, char)> { |
| // No need to go through the entire string. |
| self.next_back() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> DoubleEndedIterator for CharIndices<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<(usize, char)> { |
| self.iter.next_back().map(|ch| { |
| let index = self.front_offset + self.iter.iter.len(); |
| (index, ch) |
| }) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl FusedIterator for CharIndices<'_> {} |
| |
| impl<'a> CharIndices<'a> { |
| /// View the underlying data as a subslice of the original data. |
| /// |
| /// This has the same lifetime as the original slice, and so the |
| /// iterator can continue to be used while this exists. |
| #[stable(feature = "iter_to_slice", since = "1.4.0")] |
| #[inline] |
| pub fn as_str(&self) -> &'a str { |
| self.iter.as_str() |
| } |
| } |
| |
| /// An iterator over the bytes of a string slice. |
| /// |
| /// This struct is created by the [`bytes`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`bytes`]: ../../std/primitive.str.html#method.bytes |
| /// [`str`]: ../../std/primitive.str.html |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[derive(Clone, Debug)] |
| pub struct Bytes<'a>(Cloned<slice::Iter<'a, u8>>); |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl Iterator for Bytes<'_> { |
| type Item = u8; |
| |
| #[inline] |
| fn next(&mut self) -> Option<u8> { |
| self.0.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.0.size_hint() |
| } |
| |
| #[inline] |
| fn count(self) -> usize { |
| self.0.count() |
| } |
| |
| #[inline] |
| fn last(self) -> Option<Self::Item> { |
| self.0.last() |
| } |
| |
| #[inline] |
| fn nth(&mut self, n: usize) -> Option<Self::Item> { |
| self.0.nth(n) |
| } |
| |
| #[inline] |
| fn all<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool { |
| self.0.all(f) |
| } |
| |
| #[inline] |
| fn any<F>(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool { |
| self.0.any(f) |
| } |
| |
| #[inline] |
| fn find<P>(&mut self, predicate: P) -> Option<Self::Item> where |
| P: FnMut(&Self::Item) -> bool |
| { |
| self.0.find(predicate) |
| } |
| |
| #[inline] |
| fn position<P>(&mut self, predicate: P) -> Option<usize> where |
| P: FnMut(Self::Item) -> bool |
| { |
| self.0.position(predicate) |
| } |
| |
| #[inline] |
| fn rposition<P>(&mut self, predicate: P) -> Option<usize> where |
| P: FnMut(Self::Item) -> bool |
| { |
| self.0.rposition(predicate) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl DoubleEndedIterator for Bytes<'_> { |
| #[inline] |
| fn next_back(&mut self) -> Option<u8> { |
| self.0.next_back() |
| } |
| |
| #[inline] |
| fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item> where |
| P: FnMut(&Self::Item) -> bool |
| { |
| self.0.rfind(predicate) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ExactSizeIterator for Bytes<'_> { |
| #[inline] |
| fn len(&self) -> usize { |
| self.0.len() |
| } |
| |
| #[inline] |
| fn is_empty(&self) -> bool { |
| self.0.is_empty() |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl FusedIterator for Bytes<'_> {} |
| |
| #[unstable(feature = "trusted_len", issue = "37572")] |
| unsafe impl TrustedLen for Bytes<'_> {} |
| |
| #[doc(hidden)] |
| unsafe impl<'a> TrustedRandomAccess for Bytes<'a> { |
| unsafe fn get_unchecked(&mut self, i: usize) -> u8 { |
| self.0.get_unchecked(i) |
| } |
| fn may_have_side_effect() -> bool { false } |
| } |
| |
| /// This macro generates a Clone impl for string pattern API |
| /// wrapper types of the form X<'a, P> |
| macro_rules! derive_pattern_clone { |
| (clone $t:ident with |$s:ident| $e:expr) => { |
| impl<'a, P: Pattern<'a>> Clone for $t<'a, P> |
| where P::Searcher: Clone |
| { |
| fn clone(&self) -> Self { |
| let $s = self; |
| $e |
| } |
| } |
| } |
| } |
| |
| /// This macro generates two public iterator structs |
| /// wrapping a private internal one that makes use of the `Pattern` API. |
| /// |
| /// For all patterns `P: Pattern<'a>` the following items will be |
| /// generated (generics omitted): |
| /// |
| /// struct $forward_iterator($internal_iterator); |
| /// struct $reverse_iterator($internal_iterator); |
| /// |
| /// impl Iterator for $forward_iterator |
| /// { /* internal ends up calling Searcher::next_match() */ } |
| /// |
| /// impl DoubleEndedIterator for $forward_iterator |
| /// where P::Searcher: DoubleEndedSearcher |
| /// { /* internal ends up calling Searcher::next_match_back() */ } |
| /// |
| /// impl Iterator for $reverse_iterator |
| /// where P::Searcher: ReverseSearcher |
| /// { /* internal ends up calling Searcher::next_match_back() */ } |
| /// |
| /// impl DoubleEndedIterator for $reverse_iterator |
| /// where P::Searcher: DoubleEndedSearcher |
| /// { /* internal ends up calling Searcher::next_match() */ } |
| /// |
| /// The internal one is defined outside the macro, and has almost the same |
| /// semantic as a DoubleEndedIterator by delegating to `pattern::Searcher` and |
| /// `pattern::ReverseSearcher` for both forward and reverse iteration. |
| /// |
| /// "Almost", because a `Searcher` and a `ReverseSearcher` for a given |
| /// `Pattern` might not return the same elements, so actually implementing |
| /// `DoubleEndedIterator` for it would be incorrect. |
| /// (See the docs in `str::pattern` for more details) |
| /// |
| /// However, the internal struct still represents a single ended iterator from |
| /// either end, and depending on pattern is also a valid double ended iterator, |
| /// so the two wrapper structs implement `Iterator` |
| /// and `DoubleEndedIterator` depending on the concrete pattern type, leading |
| /// to the complex impls seen above. |
| macro_rules! generate_pattern_iterators { |
| { |
| // Forward iterator |
| forward: |
| $(#[$forward_iterator_attribute:meta])* |
| struct $forward_iterator:ident; |
| |
| // Reverse iterator |
| reverse: |
| $(#[$reverse_iterator_attribute:meta])* |
| struct $reverse_iterator:ident; |
| |
| // Stability of all generated items |
| stability: |
| $(#[$common_stability_attribute:meta])* |
| |
| // Internal almost-iterator that is being delegated to |
| internal: |
| $internal_iterator:ident yielding ($iterty:ty); |
| |
| // Kind of delegation - either single ended or double ended |
| delegate $($t:tt)* |
| } => { |
| $(#[$forward_iterator_attribute])* |
| $(#[$common_stability_attribute])* |
| pub struct $forward_iterator<'a, P: Pattern<'a>>($internal_iterator<'a, P>); |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> fmt::Debug for $forward_iterator<'a, P> |
| where P::Searcher: fmt::Debug |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_tuple(stringify!($forward_iterator)) |
| .field(&self.0) |
| .finish() |
| } |
| } |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> Iterator for $forward_iterator<'a, P> { |
| type Item = $iterty; |
| |
| #[inline] |
| fn next(&mut self) -> Option<$iterty> { |
| self.0.next() |
| } |
| } |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> Clone for $forward_iterator<'a, P> |
| where P::Searcher: Clone |
| { |
| fn clone(&self) -> Self { |
| $forward_iterator(self.0.clone()) |
| } |
| } |
| |
| $(#[$reverse_iterator_attribute])* |
| $(#[$common_stability_attribute])* |
| pub struct $reverse_iterator<'a, P: Pattern<'a>>($internal_iterator<'a, P>); |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> fmt::Debug for $reverse_iterator<'a, P> |
| where P::Searcher: fmt::Debug |
| { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_tuple(stringify!($reverse_iterator)) |
| .field(&self.0) |
| .finish() |
| } |
| } |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> Iterator for $reverse_iterator<'a, P> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| type Item = $iterty; |
| |
| #[inline] |
| fn next(&mut self) -> Option<$iterty> { |
| self.0.next_back() |
| } |
| } |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> Clone for $reverse_iterator<'a, P> |
| where P::Searcher: Clone |
| { |
| fn clone(&self) -> Self { |
| $reverse_iterator(self.0.clone()) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<'a, P: Pattern<'a>> FusedIterator for $forward_iterator<'a, P> {} |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl<'a, P: Pattern<'a>> FusedIterator for $reverse_iterator<'a, P> |
| where P::Searcher: ReverseSearcher<'a> {} |
| |
| generate_pattern_iterators!($($t)* with $(#[$common_stability_attribute])*, |
| $forward_iterator, |
| $reverse_iterator, $iterty); |
| }; |
| { |
| double ended; with $(#[$common_stability_attribute:meta])*, |
| $forward_iterator:ident, |
| $reverse_iterator:ident, $iterty:ty |
| } => { |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> DoubleEndedIterator for $forward_iterator<'a, P> |
| where P::Searcher: DoubleEndedSearcher<'a> |
| { |
| #[inline] |
| fn next_back(&mut self) -> Option<$iterty> { |
| self.0.next_back() |
| } |
| } |
| |
| $(#[$common_stability_attribute])* |
| impl<'a, P: Pattern<'a>> DoubleEndedIterator for $reverse_iterator<'a, P> |
| where P::Searcher: DoubleEndedSearcher<'a> |
| { |
| #[inline] |
| fn next_back(&mut self) -> Option<$iterty> { |
| self.0.next() |
| } |
| } |
| }; |
| { |
| single ended; with $(#[$common_stability_attribute:meta])*, |
| $forward_iterator:ident, |
| $reverse_iterator:ident, $iterty:ty |
| } => {} |
| } |
| |
| derive_pattern_clone!{ |
| clone SplitInternal |
| with |s| SplitInternal { matcher: s.matcher.clone(), ..*s } |
| } |
| |
| struct SplitInternal<'a, P: Pattern<'a>> { |
| start: usize, |
| end: usize, |
| matcher: P::Searcher, |
| allow_trailing_empty: bool, |
| finished: bool, |
| } |
| |
| impl<'a, P: Pattern<'a>> fmt::Debug for SplitInternal<'a, P> where P::Searcher: fmt::Debug { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("SplitInternal") |
| .field("start", &self.start) |
| .field("end", &self.end) |
| .field("matcher", &self.matcher) |
| .field("allow_trailing_empty", &self.allow_trailing_empty) |
| .field("finished", &self.finished) |
| .finish() |
| } |
| } |
| |
| impl<'a, P: Pattern<'a>> SplitInternal<'a, P> { |
| #[inline] |
| fn get_end(&mut self) -> Option<&'a str> { |
| if !self.finished && (self.allow_trailing_empty || self.end - self.start > 0) { |
| self.finished = true; |
| unsafe { |
| let string = self.matcher.haystack().get_unchecked(self.start..self.end); |
| Some(string) |
| } |
| } else { |
| None |
| } |
| } |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| if self.finished { return None } |
| |
| let haystack = self.matcher.haystack(); |
| match self.matcher.next_match() { |
| Some((a, b)) => unsafe { |
| let elt = haystack.get_unchecked(self.start..a); |
| self.start = b; |
| Some(elt) |
| }, |
| None => self.get_end(), |
| } |
| } |
| |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| if self.finished { return None } |
| |
| if !self.allow_trailing_empty { |
| self.allow_trailing_empty = true; |
| match self.next_back() { |
| Some(elt) if !elt.is_empty() => return Some(elt), |
| _ => if self.finished { return None } |
| } |
| } |
| |
| let haystack = self.matcher.haystack(); |
| match self.matcher.next_match_back() { |
| Some((a, b)) => unsafe { |
| let elt = haystack.get_unchecked(b..self.end); |
| self.end = a; |
| Some(elt) |
| }, |
| None => unsafe { |
| self.finished = true; |
| Some(haystack.get_unchecked(self.start..self.end)) |
| }, |
| } |
| } |
| } |
| |
| generate_pattern_iterators! { |
| forward: |
| /// Created with the method [`split`]. |
| /// |
| /// [`split`]: ../../std/primitive.str.html#method.split |
| struct Split; |
| reverse: |
| /// Created with the method [`rsplit`]. |
| /// |
| /// [`rsplit`]: ../../std/primitive.str.html#method.rsplit |
| struct RSplit; |
| stability: |
| #[stable(feature = "rust1", since = "1.0.0")] |
| internal: |
| SplitInternal yielding (&'a str); |
| delegate double ended; |
| } |
| |
| generate_pattern_iterators! { |
| forward: |
| /// Created with the method [`split_terminator`]. |
| /// |
| /// [`split_terminator`]: ../../std/primitive.str.html#method.split_terminator |
| struct SplitTerminator; |
| reverse: |
| /// Created with the method [`rsplit_terminator`]. |
| /// |
| /// [`rsplit_terminator`]: ../../std/primitive.str.html#method.rsplit_terminator |
| struct RSplitTerminator; |
| stability: |
| #[stable(feature = "rust1", since = "1.0.0")] |
| internal: |
| SplitInternal yielding (&'a str); |
| delegate double ended; |
| } |
| |
| derive_pattern_clone!{ |
| clone SplitNInternal |
| with |s| SplitNInternal { iter: s.iter.clone(), ..*s } |
| } |
| |
| struct SplitNInternal<'a, P: Pattern<'a>> { |
| iter: SplitInternal<'a, P>, |
| /// The number of splits remaining |
| count: usize, |
| } |
| |
| impl<'a, P: Pattern<'a>> fmt::Debug for SplitNInternal<'a, P> where P::Searcher: fmt::Debug { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_struct("SplitNInternal") |
| .field("iter", &self.iter) |
| .field("count", &self.count) |
| .finish() |
| } |
| } |
| |
| impl<'a, P: Pattern<'a>> SplitNInternal<'a, P> { |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| match self.count { |
| 0 => None, |
| 1 => { self.count = 0; self.iter.get_end() } |
| _ => { self.count -= 1; self.iter.next() } |
| } |
| } |
| |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| match self.count { |
| 0 => None, |
| 1 => { self.count = 0; self.iter.get_end() } |
| _ => { self.count -= 1; self.iter.next_back() } |
| } |
| } |
| } |
| |
| generate_pattern_iterators! { |
| forward: |
| /// Created with the method [`splitn`]. |
| /// |
| /// [`splitn`]: ../../std/primitive.str.html#method.splitn |
| struct SplitN; |
| reverse: |
| /// Created with the method [`rsplitn`]. |
| /// |
| /// [`rsplitn`]: ../../std/primitive.str.html#method.rsplitn |
| struct RSplitN; |
| stability: |
| #[stable(feature = "rust1", since = "1.0.0")] |
| internal: |
| SplitNInternal yielding (&'a str); |
| delegate single ended; |
| } |
| |
| derive_pattern_clone!{ |
| clone MatchIndicesInternal |
| with |s| MatchIndicesInternal(s.0.clone()) |
| } |
| |
| struct MatchIndicesInternal<'a, P: Pattern<'a>>(P::Searcher); |
| |
| impl<'a, P: Pattern<'a>> fmt::Debug for MatchIndicesInternal<'a, P> where P::Searcher: fmt::Debug { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_tuple("MatchIndicesInternal") |
| .field(&self.0) |
| .finish() |
| } |
| } |
| |
| impl<'a, P: Pattern<'a>> MatchIndicesInternal<'a, P> { |
| #[inline] |
| fn next(&mut self) -> Option<(usize, &'a str)> { |
| self.0.next_match().map(|(start, end)| unsafe { |
| (start, self.0.haystack().get_unchecked(start..end)) |
| }) |
| } |
| |
| #[inline] |
| fn next_back(&mut self) -> Option<(usize, &'a str)> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| self.0.next_match_back().map(|(start, end)| unsafe { |
| (start, self.0.haystack().get_unchecked(start..end)) |
| }) |
| } |
| } |
| |
| generate_pattern_iterators! { |
| forward: |
| /// Created with the method [`match_indices`]. |
| /// |
| /// [`match_indices`]: ../../std/primitive.str.html#method.match_indices |
| struct MatchIndices; |
| reverse: |
| /// Created with the method [`rmatch_indices`]. |
| /// |
| /// [`rmatch_indices`]: ../../std/primitive.str.html#method.rmatch_indices |
| struct RMatchIndices; |
| stability: |
| #[stable(feature = "str_match_indices", since = "1.5.0")] |
| internal: |
| MatchIndicesInternal yielding ((usize, &'a str)); |
| delegate double ended; |
| } |
| |
| derive_pattern_clone!{ |
| clone MatchesInternal |
| with |s| MatchesInternal(s.0.clone()) |
| } |
| |
| struct MatchesInternal<'a, P: Pattern<'a>>(P::Searcher); |
| |
| impl<'a, P: Pattern<'a>> fmt::Debug for MatchesInternal<'a, P> where P::Searcher: fmt::Debug { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.debug_tuple("MatchesInternal") |
| .field(&self.0) |
| .finish() |
| } |
| } |
| |
| impl<'a, P: Pattern<'a>> MatchesInternal<'a, P> { |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.0.next_match().map(|(a, b)| unsafe { |
| // Indices are known to be on utf8 boundaries |
| self.0.haystack().get_unchecked(a..b) |
| }) |
| } |
| |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| self.0.next_match_back().map(|(a, b)| unsafe { |
| // Indices are known to be on utf8 boundaries |
| self.0.haystack().get_unchecked(a..b) |
| }) |
| } |
| } |
| |
| generate_pattern_iterators! { |
| forward: |
| /// Created with the method [`matches`]. |
| /// |
| /// [`matches`]: ../../std/primitive.str.html#method.matches |
| struct Matches; |
| reverse: |
| /// Created with the method [`rmatches`]. |
| /// |
| /// [`rmatches`]: ../../std/primitive.str.html#method.rmatches |
| struct RMatches; |
| stability: |
| #[stable(feature = "str_matches", since = "1.2.0")] |
| internal: |
| MatchesInternal yielding (&'a str); |
| delegate double ended; |
| } |
| |
| /// An iterator over the lines of a string, as string slices. |
| /// |
| /// This struct is created with the [`lines`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`lines`]: ../../std/primitive.str.html#method.lines |
| /// [`str`]: ../../std/primitive.str.html |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[derive(Clone, Debug)] |
| pub struct Lines<'a>(Map<SplitTerminator<'a, char>, LinesAnyMap>); |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> Iterator for Lines<'a> { |
| type Item = &'a str; |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.0.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.0.size_hint() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> DoubleEndedIterator for Lines<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> { |
| self.0.next_back() |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl FusedIterator for Lines<'_> {} |
| |
| /// Created with the method [`lines_any`]. |
| /// |
| /// [`lines_any`]: ../../std/primitive.str.html#method.lines_any |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(since = "1.4.0", reason = "use lines()/Lines instead now")] |
| #[derive(Clone, Debug)] |
| #[allow(deprecated)] |
| pub struct LinesAny<'a>(Lines<'a>); |
| |
| /// A nameable, cloneable fn type |
| #[derive(Clone)] |
| struct LinesAnyMap; |
| |
| impl<'a> Fn<(&'a str,)> for LinesAnyMap { |
| #[inline] |
| extern "rust-call" fn call(&self, (line,): (&'a str,)) -> &'a str { |
| let l = line.len(); |
| if l > 0 && line.as_bytes()[l - 1] == b'\r' { &line[0 .. l - 1] } |
| else { line } |
| } |
| } |
| |
| impl<'a> FnMut<(&'a str,)> for LinesAnyMap { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, (line,): (&'a str,)) -> &'a str { |
| Fn::call(&*self, (line,)) |
| } |
| } |
| |
| impl<'a> FnOnce<(&'a str,)> for LinesAnyMap { |
| type Output = &'a str; |
| |
| #[inline] |
| extern "rust-call" fn call_once(self, (line,): (&'a str,)) -> &'a str { |
| Fn::call(&self, (line,)) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| impl<'a> Iterator for LinesAny<'a> { |
| type Item = &'a str; |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.0.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.0.size_hint() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| impl<'a> DoubleEndedIterator for LinesAny<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> { |
| self.0.next_back() |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| #[allow(deprecated)] |
| impl FusedIterator for LinesAny<'_> {} |
| |
| /* |
| Section: UTF-8 validation |
| */ |
| |
| // use truncation to fit u64 into usize |
| const NONASCII_MASK: usize = 0x80808080_80808080u64 as usize; |
| |
| /// Returns `true` if any byte in the word `x` is nonascii (>= 128). |
| #[inline] |
| fn contains_nonascii(x: usize) -> bool { |
| (x & NONASCII_MASK) != 0 |
| } |
| |
| /// Walks through `v` checking that it's a valid UTF-8 sequence, |
| /// returning `Ok(())` in that case, or, if it is invalid, `Err(err)`. |
| #[inline] |
| fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> { |
| let mut index = 0; |
| let len = v.len(); |
| |
| let usize_bytes = mem::size_of::<usize>(); |
| let ascii_block_size = 2 * usize_bytes; |
| let blocks_end = if len >= ascii_block_size { len - ascii_block_size + 1 } else { 0 }; |
| |
| while index < len { |
| let old_offset = index; |
| macro_rules! err { |
| ($error_len: expr) => { |
| return Err(Utf8Error { |
| valid_up_to: old_offset, |
| error_len: $error_len, |
| }) |
| } |
| } |
| |
| macro_rules! next { () => {{ |
| index += 1; |
| // we needed data, but there was none: error! |
| if index >= len { |
| err!(None) |
| } |
| v[index] |
| }}} |
| |
| let first = v[index]; |
| if first >= 128 { |
| let w = UTF8_CHAR_WIDTH[first as usize]; |
| // 2-byte encoding is for codepoints \u{0080} to \u{07ff} |
| // first C2 80 last DF BF |
| // 3-byte encoding is for codepoints \u{0800} to \u{ffff} |
| // first E0 A0 80 last EF BF BF |
| // excluding surrogates codepoints \u{d800} to \u{dfff} |
| // ED A0 80 to ED BF BF |
| // 4-byte encoding is for codepoints \u{1000}0 to \u{10ff}ff |
| // first F0 90 80 80 last F4 8F BF BF |
| // |
| // Use the UTF-8 syntax from the RFC |
| // |
| // https://tools.ietf.org/html/rfc3629 |
| // UTF8-1 = %x00-7F |
| // UTF8-2 = %xC2-DF UTF8-tail |
| // UTF8-3 = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2( UTF8-tail ) / |
| // %xED %x80-9F UTF8-tail / %xEE-EF 2( UTF8-tail ) |
| // UTF8-4 = %xF0 %x90-BF 2( UTF8-tail ) / %xF1-F3 3( UTF8-tail ) / |
| // %xF4 %x80-8F 2( UTF8-tail ) |
| match w { |
| 2 => if next!() & !CONT_MASK != TAG_CONT_U8 { |
| err!(Some(1)) |
| }, |
| 3 => { |
| match (first, next!()) { |
| (0xE0 , 0xA0 ..= 0xBF) | |
| (0xE1 ..= 0xEC, 0x80 ..= 0xBF) | |
| (0xED , 0x80 ..= 0x9F) | |
| (0xEE ..= 0xEF, 0x80 ..= 0xBF) => {} |
| _ => err!(Some(1)) |
| } |
| if next!() & !CONT_MASK != TAG_CONT_U8 { |
| err!(Some(2)) |
| } |
| } |
| 4 => { |
| match (first, next!()) { |
| (0xF0 , 0x90 ..= 0xBF) | |
| (0xF1 ..= 0xF3, 0x80 ..= 0xBF) | |
| (0xF4 , 0x80 ..= 0x8F) => {} |
| _ => err!(Some(1)) |
| } |
| if next!() & !CONT_MASK != TAG_CONT_U8 { |
| err!(Some(2)) |
| } |
| if next!() & !CONT_MASK != TAG_CONT_U8 { |
| err!(Some(3)) |
| } |
| } |
| _ => err!(Some(1)) |
| } |
| index += 1; |
| } else { |
| // Ascii case, try to skip forward quickly. |
| // When the pointer is aligned, read 2 words of data per iteration |
| // until we find a word containing a non-ascii byte. |
| let ptr = v.as_ptr(); |
| let align = unsafe { |
| // the offset is safe, because `index` is guaranteed inbounds |
| ptr.add(index).align_offset(usize_bytes) |
| }; |
| if align == 0 { |
| while index < blocks_end { |
| unsafe { |
| let block = ptr.add(index) as *const usize; |
| // break if there is a nonascii byte |
| let zu = contains_nonascii(*block); |
| let zv = contains_nonascii(*block.offset(1)); |
| if zu | zv { |
| break; |
| } |
| } |
| index += ascii_block_size; |
| } |
| // step from the point where the wordwise loop stopped |
| while index < len && v[index] < 128 { |
| index += 1; |
| } |
| } else { |
| index += 1; |
| } |
| } |
| } |
| |
| Ok(()) |
| } |
| |
| // https://tools.ietf.org/html/rfc3629 |
| static UTF8_CHAR_WIDTH: [u8; 256] = [ |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x1F |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x3F |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x5F |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, // 0x7F |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 0x9F |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, // 0xBF |
| 0,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2, |
| 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // 0xDF |
| 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, // 0xEF |
| 4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0, // 0xFF |
| ]; |
| |
| /// Given a first byte, determines how many bytes are in this UTF-8 character. |
| #[unstable(feature = "str_internals", issue = "0")] |
| #[inline] |
| pub fn utf8_char_width(b: u8) -> usize { |
| UTF8_CHAR_WIDTH[b as usize] as usize |
| } |
| |
| /// Mask of the value bits of a continuation byte. |
| const CONT_MASK: u8 = 0b0011_1111; |
| /// Value of the tag bits (tag mask is !CONT_MASK) of a continuation byte. |
| const TAG_CONT_U8: u8 = 0b1000_0000; |
| |
| /* |
| Section: Trait implementations |
| */ |
| |
| mod traits { |
| use cmp::Ordering; |
| use ops; |
| use slice::{self, SliceIndex}; |
| |
| /// Implements ordering of strings. |
| /// |
| /// Strings are ordered lexicographically by their byte values. This orders Unicode code |
| /// points based on their positions in the code charts. This is not necessarily the same as |
| /// "alphabetical" order, which varies by language and locale. Sorting strings according to |
| /// culturally-accepted standards requires locale-specific data that is outside the scope of |
| /// the `str` type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl Ord for str { |
| #[inline] |
| fn cmp(&self, other: &str) -> Ordering { |
| self.as_bytes().cmp(other.as_bytes()) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl PartialEq for str { |
| #[inline] |
| fn eq(&self, other: &str) -> bool { |
| self.as_bytes() == other.as_bytes() |
| } |
| #[inline] |
| fn ne(&self, other: &str) -> bool { !(*self).eq(other) } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl Eq for str {} |
| |
| /// Implements comparison operations on strings. |
| /// |
| /// Strings are compared lexicographically by their byte values. This compares Unicode code |
| /// points based on their positions in the code charts. This is not necessarily the same as |
| /// "alphabetical" order, which varies by language and locale. Comparing strings according to |
| /// culturally-accepted standards requires locale-specific data that is outside the scope of |
| /// the `str` type. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl PartialOrd for str { |
| #[inline] |
| fn partial_cmp(&self, other: &str) -> Option<Ordering> { |
| Some(self.cmp(other)) |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[begin .. end]`. |
| /// |
| /// Returns a slice of the given string from the byte range |
| /// [`begin`..`end`). |
| /// |
| /// This operation is `O(1)`. |
| /// |
| /// # Panics |
| /// |
| /// Panics if `begin` or `end` does not point to the starting |
| /// byte offset of a character (as defined by `is_char_boundary`). |
| /// Requires that `begin <= end` and `end <= len` where `len` is the |
| /// length of the string. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// assert_eq!(&s[0 .. 1], "L"); |
| /// |
| /// assert_eq!(&s[1 .. 9], "öwe 老"); |
| /// |
| /// // these will panic: |
| /// // byte 2 lies within `ö`: |
| /// // &s[2 ..3]; |
| /// |
| /// // byte 8 lies within `老` |
| /// // &s[1 .. 8]; |
| /// |
| /// // byte 100 is outside the string |
| /// // &s[3 .. 100]; |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::Range<usize>> for str { |
| type Output = str; |
| #[inline] |
| fn index(&self, index: ops::Range<usize>) -> &str { |
| index.index(self) |
| } |
| } |
| |
| /// Implements mutable substring slicing with syntax |
| /// `&mut self[begin .. end]`. |
| /// |
| /// Returns a mutable slice of the given string from the byte range |
| /// [`begin`..`end`). |
| /// |
| /// This operation is `O(1)`. |
| /// |
| /// # Panics |
| /// |
| /// Panics if `begin` or `end` does not point to the starting |
| /// byte offset of a character (as defined by `is_char_boundary`). |
| /// Requires that `begin <= end` and `end <= len` where `len` is the |
| /// length of the string. |
| #[stable(feature = "derefmut_for_string", since = "1.3.0")] |
| impl ops::IndexMut<ops::Range<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::Range<usize>) -> &mut str { |
| index.index_mut(self) |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[.. end]`. |
| /// |
| /// Returns a slice of the string from the beginning to byte offset |
| /// `end`. |
| /// |
| /// Equivalent to `&self[0 .. end]`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::RangeTo<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeTo<usize>) -> &str { |
| index.index(self) |
| } |
| } |
| |
| /// Implements mutable substring slicing with syntax `&mut self[.. end]`. |
| /// |
| /// Returns a mutable slice of the string from the beginning to byte offset |
| /// `end`. |
| /// |
| /// Equivalent to `&mut self[0 .. end]`. |
| #[stable(feature = "derefmut_for_string", since = "1.3.0")] |
| impl ops::IndexMut<ops::RangeTo<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut str { |
| index.index_mut(self) |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[begin ..]`. |
| /// |
| /// Returns a slice of the string from byte offset `begin` |
| /// to the end of the string. |
| /// |
| /// Equivalent to `&self[begin .. len]`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::RangeFrom<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeFrom<usize>) -> &str { |
| index.index(self) |
| } |
| } |
| |
| /// Implements mutable substring slicing with syntax `&mut self[begin ..]`. |
| /// |
| /// Returns a mutable slice of the string from byte offset `begin` |
| /// to the end of the string. |
| /// |
| /// Equivalent to `&mut self[begin .. len]`. |
| #[stable(feature = "derefmut_for_string", since = "1.3.0")] |
| impl ops::IndexMut<ops::RangeFrom<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut str { |
| index.index_mut(self) |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[..]`. |
| /// |
| /// Returns a slice of the whole string. This operation can |
| /// never panic. |
| /// |
| /// Equivalent to `&self[0 .. len]`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::RangeFull> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, _index: ops::RangeFull) -> &str { |
| self |
| } |
| } |
| |
| /// Implements mutable substring slicing with syntax `&mut self[..]`. |
| /// |
| /// Returns a mutable slice of the whole string. This operation can |
| /// never panic. |
| /// |
| /// Equivalent to `&mut self[0 .. len]`. |
| #[stable(feature = "derefmut_for_string", since = "1.3.0")] |
| impl ops::IndexMut<ops::RangeFull> for str { |
| #[inline] |
| fn index_mut(&mut self, _index: ops::RangeFull) -> &mut str { |
| self |
| } |
| } |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl ops::Index<ops::RangeInclusive<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeInclusive<usize>) -> &str { |
| index.index(self) |
| } |
| } |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl ops::Index<ops::RangeToInclusive<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeToInclusive<usize>) -> &str { |
| index.index(self) |
| } |
| } |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl ops::IndexMut<ops::RangeInclusive<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut str { |
| index.index_mut(self) |
| } |
| } |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl ops::IndexMut<ops::RangeToInclusive<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut str { |
| index.index_mut(self) |
| } |
| } |
| |
| #[inline(never)] |
| #[cold] |
| fn str_index_overflow_fail() -> ! { |
| panic!("attempted to index str up to maximum usize"); |
| } |
| |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| impl SliceIndex<str> for ops::RangeFull { |
| type Output = str; |
| #[inline] |
| fn get(self, slice: &str) -> Option<&Self::Output> { |
| Some(slice) |
| } |
| #[inline] |
| fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { |
| Some(slice) |
| } |
| #[inline] |
| unsafe fn get_unchecked(self, slice: &str) -> &Self::Output { |
| slice |
| } |
| #[inline] |
| unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output { |
| slice |
| } |
| #[inline] |
| fn index(self, slice: &str) -> &Self::Output { |
| slice |
| } |
| #[inline] |
| fn index_mut(self, slice: &mut str) -> &mut Self::Output { |
| slice |
| } |
| } |
| |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| impl SliceIndex<str> for ops::Range<usize> { |
| type Output = str; |
| #[inline] |
| fn get(self, slice: &str) -> Option<&Self::Output> { |
| if self.start <= self.end && |
| slice.is_char_boundary(self.start) && |
| slice.is_char_boundary(self.end) { |
| Some(unsafe { self.get_unchecked(slice) }) |
| } else { |
| None |
| } |
| } |
| #[inline] |
| fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { |
| if self.start <= self.end && |
| slice.is_char_boundary(self.start) && |
| slice.is_char_boundary(self.end) { |
| Some(unsafe { self.get_unchecked_mut(slice) }) |
| } else { |
| None |
| } |
| } |
| #[inline] |
| unsafe fn get_unchecked(self, slice: &str) -> &Self::Output { |
| let ptr = slice.as_ptr().add(self.start); |
| let len = self.end - self.start; |
| super::from_utf8_unchecked(slice::from_raw_parts(ptr, len)) |
| } |
| #[inline] |
| unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output { |
| let ptr = slice.as_ptr().add(self.start); |
| let len = self.end - self.start; |
| super::from_utf8_unchecked_mut(slice::from_raw_parts_mut(ptr as *mut u8, len)) |
| } |
| #[inline] |
| fn index(self, slice: &str) -> &Self::Output { |
| let (start, end) = (self.start, self.end); |
| self.get(slice).unwrap_or_else(|| super::slice_error_fail(slice, start, end)) |
| } |
| #[inline] |
| fn index_mut(self, slice: &mut str) -> &mut Self::Output { |
| // is_char_boundary checks that the index is in [0, .len()] |
| // cannot reuse `get` as above, because of NLL trouble |
| if self.start <= self.end && |
| slice.is_char_boundary(self.start) && |
| slice.is_char_boundary(self.end) { |
| unsafe { self.get_unchecked_mut(slice) } |
| } else { |
| super::slice_error_fail(slice, self.start, self.end) |
| } |
| } |
| } |
| |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| impl SliceIndex<str> for ops::RangeTo<usize> { |
| type Output = str; |
| #[inline] |
| fn get(self, slice: &str) -> Option<&Self::Output> { |
| if slice.is_char_boundary(self.end) { |
| Some(unsafe { self.get_unchecked(slice) }) |
| } else { |
| None |
| } |
| } |
| #[inline] |
| fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { |
| if slice.is_char_boundary(self.end) { |
| Some(unsafe { self.get_unchecked_mut(slice) }) |
| } else { |
| None |
| } |
| } |
| #[inline] |
| unsafe fn get_unchecked(self, slice: &str) -> &Self::Output { |
| let ptr = slice.as_ptr(); |
| super::from_utf8_unchecked(slice::from_raw_parts(ptr, self.end)) |
| } |
| #[inline] |
| unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output { |
| let ptr = slice.as_ptr(); |
| super::from_utf8_unchecked_mut(slice::from_raw_parts_mut(ptr as *mut u8, self.end)) |
| } |
| #[inline] |
| fn index(self, slice: &str) -> &Self::Output { |
| let end = self.end; |
| self.get(slice).unwrap_or_else(|| super::slice_error_fail(slice, 0, end)) |
| } |
| #[inline] |
| fn index_mut(self, slice: &mut str) -> &mut Self::Output { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if slice.is_char_boundary(self.end) { |
| unsafe { self.get_unchecked_mut(slice) } |
| } else { |
| super::slice_error_fail(slice, 0, self.end) |
| } |
| } |
| } |
| |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| impl SliceIndex<str> for ops::RangeFrom<usize> { |
| type Output = str; |
| #[inline] |
| fn get(self, slice: &str) -> Option<&Self::Output> { |
| if slice.is_char_boundary(self.start) { |
| Some(unsafe { self.get_unchecked(slice) }) |
| } else { |
| None |
| } |
| } |
| #[inline] |
| fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { |
| if slice.is_char_boundary(self.start) { |
| Some(unsafe { self.get_unchecked_mut(slice) }) |
| } else { |
| None |
| } |
| } |
| #[inline] |
| unsafe fn get_unchecked(self, slice: &str) -> &Self::Output { |
| let ptr = slice.as_ptr().add(self.start); |
| let len = slice.len() - self.start; |
| super::from_utf8_unchecked(slice::from_raw_parts(ptr, len)) |
| } |
| #[inline] |
| unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output { |
| let ptr = slice.as_ptr().add(self.start); |
| let len = slice.len() - self.start; |
| super::from_utf8_unchecked_mut(slice::from_raw_parts_mut(ptr as *mut u8, len)) |
| } |
| #[inline] |
| fn index(self, slice: &str) -> &Self::Output { |
| let (start, end) = (self.start, slice.len()); |
| self.get(slice).unwrap_or_else(|| super::slice_error_fail(slice, start, end)) |
| } |
| #[inline] |
| fn index_mut(self, slice: &mut str) -> &mut Self::Output { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if slice.is_char_boundary(self.start) { |
| unsafe { self.get_unchecked_mut(slice) } |
| } else { |
| super::slice_error_fail(slice, self.start, slice.len()) |
| } |
| } |
| } |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl SliceIndex<str> for ops::RangeInclusive<usize> { |
| type Output = str; |
| #[inline] |
| fn get(self, slice: &str) -> Option<&Self::Output> { |
| if *self.end() == usize::max_value() { None } |
| else { (*self.start()..self.end()+1).get(slice) } |
| } |
| #[inline] |
| fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { |
| if *self.end() == usize::max_value() { None } |
| else { (*self.start()..self.end()+1).get_mut(slice) } |
| } |
| #[inline] |
| unsafe fn get_unchecked(self, slice: &str) -> &Self::Output { |
| (*self.start()..self.end()+1).get_unchecked(slice) |
| } |
| #[inline] |
| unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output { |
| (*self.start()..self.end()+1).get_unchecked_mut(slice) |
| } |
| #[inline] |
| fn index(self, slice: &str) -> &Self::Output { |
| if *self.end() == usize::max_value() { str_index_overflow_fail(); } |
| (*self.start()..self.end()+1).index(slice) |
| } |
| #[inline] |
| fn index_mut(self, slice: &mut str) -> &mut Self::Output { |
| if *self.end() == usize::max_value() { str_index_overflow_fail(); } |
| (*self.start()..self.end()+1).index_mut(slice) |
| } |
| } |
| |
| |
| |
| #[stable(feature = "inclusive_range", since = "1.26.0")] |
| impl SliceIndex<str> for ops::RangeToInclusive<usize> { |
| type Output = str; |
| #[inline] |
| fn get(self, slice: &str) -> Option<&Self::Output> { |
| if self.end == usize::max_value() { None } |
| else { (..self.end+1).get(slice) } |
| } |
| #[inline] |
| fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { |
| if self.end == usize::max_value() { None } |
| else { (..self.end+1).get_mut(slice) } |
| } |
| #[inline] |
| unsafe fn get_unchecked(self, slice: &str) -> &Self::Output { |
| (..self.end+1).get_unchecked(slice) |
| } |
| #[inline] |
| unsafe fn get_unchecked_mut(self, slice: &mut str) -> &mut Self::Output { |
| (..self.end+1).get_unchecked_mut(slice) |
| } |
| #[inline] |
| fn index(self, slice: &str) -> &Self::Output { |
| if self.end == usize::max_value() { str_index_overflow_fail(); } |
| (..self.end+1).index(slice) |
| } |
| #[inline] |
| fn index_mut(self, slice: &mut str) -> &mut Self::Output { |
| if self.end == usize::max_value() { str_index_overflow_fail(); } |
| (..self.end+1).index_mut(slice) |
| } |
| } |
| } |
| |
| // truncate `&str` to length at most equal to `max` |
| // return `true` if it were truncated, and the new str. |
| fn truncate_to_char_boundary(s: &str, mut max: usize) -> (bool, &str) { |
| if max >= s.len() { |
| (false, s) |
| } else { |
| while !s.is_char_boundary(max) { |
| max -= 1; |
| } |
| (true, &s[..max]) |
| } |
| } |
| |
| #[inline(never)] |
| #[cold] |
| fn slice_error_fail(s: &str, begin: usize, end: usize) -> ! { |
| const MAX_DISPLAY_LENGTH: usize = 256; |
| let (truncated, s_trunc) = truncate_to_char_boundary(s, MAX_DISPLAY_LENGTH); |
| let ellipsis = if truncated { "[...]" } else { "" }; |
| |
| // 1. out of bounds |
| if begin > s.len() || end > s.len() { |
| let oob_index = if begin > s.len() { begin } else { end }; |
| panic!("byte index {} is out of bounds of `{}`{}", oob_index, s_trunc, ellipsis); |
| } |
| |
| // 2. begin <= end |
| assert!(begin <= end, "begin <= end ({} <= {}) when slicing `{}`{}", |
| begin, end, s_trunc, ellipsis); |
| |
| // 3. character boundary |
| let index = if !s.is_char_boundary(begin) { begin } else { end }; |
| // find the character |
| let mut char_start = index; |
| while !s.is_char_boundary(char_start) { |
| char_start -= 1; |
| } |
| // `char_start` must be less than len and a char boundary |
| let ch = s[char_start..].chars().next().unwrap(); |
| let char_range = char_start .. char_start + ch.len_utf8(); |
| panic!("byte index {} is not a char boundary; it is inside {:?} (bytes {:?}) of `{}`{}", |
| index, ch, char_range, s_trunc, ellipsis); |
| } |
| |
| #[lang = "str"] |
| #[cfg(not(test))] |
| impl str { |
| /// Returns the length of `self`. |
| /// |
| /// This length is in bytes, not [`char`]s or graphemes. In other words, |
| /// it may not be what a human considers the length of the string. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let len = "foo".len(); |
| /// assert_eq!(3, len); |
| /// |
| /// let len = "ƒoo".len(); // fancy f! |
| /// assert_eq!(4, len); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| #[rustc_const_unstable(feature = "const_str_len")] |
| pub const fn len(&self) -> usize { |
| self.as_bytes().len() |
| } |
| |
| /// Returns `true` if `self` has a length of zero bytes. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = ""; |
| /// assert!(s.is_empty()); |
| /// |
| /// let s = "not empty"; |
| /// assert!(!s.is_empty()); |
| /// ``` |
| #[inline] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_const_unstable(feature = "const_str_len")] |
| pub const fn is_empty(&self) -> bool { |
| self.len() == 0 |
| } |
| |
| /// Checks that `index`-th byte lies at the start and/or end of a |
| /// UTF-8 code point sequence. |
| /// |
| /// The start and end of the string (when `index == self.len()`) are |
| /// considered to be |
| /// boundaries. |
| /// |
| /// Returns `false` if `index` is greater than `self.len()`. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// assert!(s.is_char_boundary(0)); |
| /// // start of `老` |
| /// assert!(s.is_char_boundary(6)); |
| /// assert!(s.is_char_boundary(s.len())); |
| /// |
| /// // second byte of `ö` |
| /// assert!(!s.is_char_boundary(2)); |
| /// |
| /// // third byte of `老` |
| /// assert!(!s.is_char_boundary(8)); |
| /// ``` |
| #[stable(feature = "is_char_boundary", since = "1.9.0")] |
| #[inline] |
| pub fn is_char_boundary(&self, index: usize) -> bool { |
| // 0 and len are always ok. |
| // Test for 0 explicitly so that it can optimize out the check |
| // easily and skip reading string data for that case. |
| if index == 0 || index == self.len() { return true; } |
| match self.as_bytes().get(index) { |
| None => false, |
| // This is bit magic equivalent to: b < 128 || b >= 192 |
| Some(&b) => (b as i8) >= -0x40, |
| } |
| } |
| |
| /// Converts a string slice to a byte slice. To convert the byte slice back |
| /// into a string slice, use the [`str::from_utf8`] function. |
| /// |
| /// [`str::from_utf8`]: ./str/fn.from_utf8.html |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let bytes = "bors".as_bytes(); |
| /// assert_eq!(b"bors", bytes); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline(always)] |
| #[rustc_const_unstable(feature="const_str_as_bytes")] |
| pub const fn as_bytes(&self) -> &[u8] { |
| union Slices<'a> { |
| str: &'a str, |
| slice: &'a [u8], |
| } |
| unsafe { Slices { str: self }.slice } |
| } |
| |
| /// Converts a mutable string slice to a mutable byte slice. To convert the |
| /// mutable byte slice back into a mutable string slice, use the |
| /// [`str::from_utf8_mut`] function. |
| /// |
| /// [`str::from_utf8_mut`]: ./str/fn.from_utf8_mut.html |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let mut s = String::from("Hello"); |
| /// let bytes = unsafe { s.as_bytes_mut() }; |
| /// |
| /// assert_eq!(b"Hello", bytes); |
| /// ``` |
| /// |
| /// Mutability: |
| /// |
| /// ``` |
| /// let mut s = String::from("🗻∈🌏"); |
| /// |
| /// unsafe { |
| /// let bytes = s.as_bytes_mut(); |
| /// |
| /// bytes[0] = 0xF0; |
| /// bytes[1] = 0x9F; |
| /// bytes[2] = 0x8D; |
| /// bytes[3] = 0x94; |
| /// } |
| /// |
| /// assert_eq!("🍔∈🌏", s); |
| /// ``` |
| #[stable(feature = "str_mut_extras", since = "1.20.0")] |
| #[inline(always)] |
| pub unsafe fn as_bytes_mut(&mut self) -> &mut [u8] { |
| &mut *(self as *mut str as *mut [u8]) |
| } |
| |
| /// Converts a string slice to a raw pointer. |
| /// |
| /// As string slices are a slice of bytes, the raw pointer points to a |
| /// [`u8`]. This pointer will be pointing to the first byte of the string |
| /// slice. |
| /// |
| /// [`u8`]: primitive.u8.html |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = "Hello"; |
| /// let ptr = s.as_ptr(); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub const fn as_ptr(&self) -> *const u8 { |
| self as *const str as *const u8 |
| } |
| |
| /// Returns a subslice of `str`. |
| /// |
| /// This is the non-panicking alternative to indexing the `str`. Returns |
| /// [`None`] whenever equivalent indexing operation would panic. |
| /// |
| /// [`None`]: option/enum.Option.html#variant.None |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let v = String::from("🗻∈🌏"); |
| /// |
| /// assert_eq!(Some("🗻"), v.get(0..4)); |
| /// |
| /// // indices not on UTF-8 sequence boundaries |
| /// assert!(v.get(1..).is_none()); |
| /// assert!(v.get(..8).is_none()); |
| /// |
| /// // out of bounds |
| /// assert!(v.get(..42).is_none()); |
| /// ``` |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| #[inline] |
| pub fn get<I: SliceIndex<str>>(&self, i: I) -> Option<&I::Output> { |
| i.get(self) |
| } |
| |
| /// Returns a mutable subslice of `str`. |
| /// |
| /// This is the non-panicking alternative to indexing the `str`. Returns |
| /// [`None`] whenever equivalent indexing operation would panic. |
| /// |
| /// [`None`]: option/enum.Option.html#variant.None |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let mut v = String::from("hello"); |
| /// // correct length |
| /// assert!(v.get_mut(0..5).is_some()); |
| /// // out of bounds |
| /// assert!(v.get_mut(..42).is_none()); |
| /// assert_eq!(Some("he"), v.get_mut(0..2).map(|v| &*v)); |
| /// |
| /// assert_eq!("hello", v); |
| /// { |
| /// let s = v.get_mut(0..2); |
| /// let s = s.map(|s| { |
| /// s.make_ascii_uppercase(); |
| /// &*s |
| /// }); |
| /// assert_eq!(Some("HE"), s); |
| /// } |
| /// assert_eq!("HEllo", v); |
| /// ``` |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| #[inline] |
| pub fn get_mut<I: SliceIndex<str>>(&mut self, i: I) -> Option<&mut I::Output> { |
| i.get_mut(self) |
| } |
| |
| /// Returns a unchecked subslice of `str`. |
| /// |
| /// This is the unchecked alternative to indexing the `str`. |
| /// |
| /// # Safety |
| /// |
| /// Callers of this function are responsible that these preconditions are |
| /// satisfied: |
| /// |
| /// * The starting index must come before the ending index; |
| /// * Indexes must be within bounds of the original slice; |
| /// * Indexes must lie on UTF-8 sequence boundaries. |
| /// |
| /// Failing that, the returned string slice may reference invalid memory or |
| /// violate the invariants communicated by the `str` type. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let v = "🗻∈🌏"; |
| /// unsafe { |
| /// assert_eq!("🗻", v.get_unchecked(0..4)); |
| /// assert_eq!("∈", v.get_unchecked(4..7)); |
| /// assert_eq!("🌏", v.get_unchecked(7..11)); |
| /// } |
| /// ``` |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| #[inline] |
| pub unsafe fn get_unchecked<I: SliceIndex<str>>(&self, i: I) -> &I::Output { |
| i.get_unchecked(self) |
| } |
| |
| /// Returns a mutable, unchecked subslice of `str`. |
| /// |
| /// This is the unchecked alternative to indexing the `str`. |
| /// |
| /// # Safety |
| /// |
| /// Callers of this function are responsible that these preconditions are |
| /// satisfied: |
| /// |
| /// * The starting index must come before the ending index; |
| /// * Indexes must be within bounds of the original slice; |
| /// * Indexes must lie on UTF-8 sequence boundaries. |
| /// |
| /// Failing that, the returned string slice may reference invalid memory or |
| /// violate the invariants communicated by the `str` type. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let mut v = String::from("🗻∈🌏"); |
| /// unsafe { |
| /// assert_eq!("🗻", v.get_unchecked_mut(0..4)); |
| /// assert_eq!("∈", v.get_unchecked_mut(4..7)); |
| /// assert_eq!("🌏", v.get_unchecked_mut(7..11)); |
| /// } |
| /// ``` |
| #[stable(feature = "str_checked_slicing", since = "1.20.0")] |
| #[inline] |
| pub unsafe fn get_unchecked_mut<I: SliceIndex<str>>(&mut self, i: I) -> &mut I::Output { |
| i.get_unchecked_mut(self) |
| } |
| |
| /// Creates a string slice from another string slice, bypassing safety |
| /// checks. |
| /// |
| /// This is generally not recommended, use with caution! For a safe |
| /// alternative see [`str`] and [`Index`]. |
| /// |
| /// [`str`]: primitive.str.html |
| /// [`Index`]: ops/trait.Index.html |
| /// |
| /// This new slice goes from `begin` to `end`, including `begin` but |
| /// excluding `end`. |
| /// |
| /// To get a mutable string slice instead, see the |
| /// [`slice_mut_unchecked`] method. |
| /// |
| /// [`slice_mut_unchecked`]: #method.slice_mut_unchecked |
| /// |
| /// # Safety |
| /// |
| /// Callers of this function are responsible that three preconditions are |
| /// satisfied: |
| /// |
| /// * `begin` must come before `end`. |
| /// * `begin` and `end` must be byte positions within the string slice. |
| /// * `begin` and `end` must lie on UTF-8 sequence boundaries. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// |
| /// unsafe { |
| /// assert_eq!("Löwe 老虎 Léopard", s.slice_unchecked(0, 21)); |
| /// } |
| /// |
| /// let s = "Hello, world!"; |
| /// |
| /// unsafe { |
| /// assert_eq!("world", s.slice_unchecked(7, 12)); |
| /// } |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(since = "1.29.0", reason = "use `get_unchecked(begin..end)` instead")] |
| #[inline] |
| pub unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str { |
| (begin..end).get_unchecked(self) |
| } |
| |
| /// Creates a string slice from another string slice, bypassing safety |
| /// checks. |
| /// This is generally not recommended, use with caution! For a safe |
| /// alternative see [`str`] and [`IndexMut`]. |
| /// |
| /// [`str`]: primitive.str.html |
| /// [`IndexMut`]: ops/trait.IndexMut.html |
| /// |
| /// This new slice goes from `begin` to `end`, including `begin` but |
| /// excluding `end`. |
| /// |
| /// To get an immutable string slice instead, see the |
| /// [`slice_unchecked`] method. |
| /// |
| /// [`slice_unchecked`]: #method.slice_unchecked |
| /// |
| /// # Safety |
| /// |
| /// Callers of this function are responsible that three preconditions are |
| /// satisfied: |
| /// |
| /// * `begin` must come before `end`. |
| /// * `begin` and `end` must be byte positions within the string slice. |
| /// * `begin` and `end` must lie on UTF-8 sequence boundaries. |
| #[stable(feature = "str_slice_mut", since = "1.5.0")] |
| #[rustc_deprecated(since = "1.29.0", reason = "use `get_unchecked_mut(begin..end)` instead")] |
| #[inline] |
| pub unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str { |
| (begin..end).get_unchecked_mut(self) |
| } |
| |
| /// Divide one string slice into two at an index. |
| /// |
| /// The argument, `mid`, should be a byte offset from the start of the |
| /// string. It must also be on the boundary of a UTF-8 code point. |
| /// |
| /// The two slices returned go from the start of the string slice to `mid`, |
| /// and from `mid` to the end of the string slice. |
| /// |
| /// To get mutable string slices instead, see the [`split_at_mut`] |
| /// method. |
| /// |
| /// [`split_at_mut`]: #method.split_at_mut |
| /// |
| /// # Panics |
| /// |
| /// Panics if `mid` is not on a UTF-8 code point boundary, or if it is |
| /// beyond the last code point of the string slice. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = "Per Martin-Löf"; |
| /// |
| /// let (first, last) = s.split_at(3); |
| /// |
| /// assert_eq!("Per", first); |
| /// assert_eq!(" Martin-Löf", last); |
| /// ``` |
| #[inline] |
| #[stable(feature = "str_split_at", since = "1.4.0")] |
| pub fn split_at(&self, mid: usize) -> (&str, &str) { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if self.is_char_boundary(mid) { |
| unsafe { |
| (self.get_unchecked(0..mid), |
| self.get_unchecked(mid..self.len())) |
| } |
| } else { |
| slice_error_fail(self, 0, mid) |
| } |
| } |
| |
| /// Divide one mutable string slice into two at an index. |
| /// |
| /// The argument, `mid`, should be a byte offset from the start of the |
| /// string. It must also be on the boundary of a UTF-8 code point. |
| /// |
| /// The two slices returned go from the start of the string slice to `mid`, |
| /// and from `mid` to the end of the string slice. |
| /// |
| /// To get immutable string slices instead, see the [`split_at`] method. |
| /// |
| /// [`split_at`]: #method.split_at |
| /// |
| /// # Panics |
| /// |
| /// Panics if `mid` is not on a UTF-8 code point boundary, or if it is |
| /// beyond the last code point of the string slice. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let mut s = "Per Martin-Löf".to_string(); |
| /// { |
| /// let (first, last) = s.split_at_mut(3); |
| /// first.make_ascii_uppercase(); |
| /// assert_eq!("PER", first); |
| /// assert_eq!(" Martin-Löf", last); |
| /// } |
| /// assert_eq!("PER Martin-Löf", s); |
| /// ``` |
| #[inline] |
| #[stable(feature = "str_split_at", since = "1.4.0")] |
| pub fn split_at_mut(&mut self, mid: usize) -> (&mut str, &mut str) { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if self.is_char_boundary(mid) { |
| let len = self.len(); |
| let ptr = self.as_ptr() as *mut u8; |
| unsafe { |
| (from_utf8_unchecked_mut(slice::from_raw_parts_mut(ptr, mid)), |
| from_utf8_unchecked_mut(slice::from_raw_parts_mut( |
| ptr.add(mid), |
| len - mid |
| ))) |
| } |
| } else { |
| slice_error_fail(self, 0, mid) |
| } |
| } |
| |
| /// Returns an iterator over the [`char`]s of a string slice. |
| /// |
| /// As a string slice consists of valid UTF-8, we can iterate through a |
| /// string slice by [`char`]. This method returns such an iterator. |
| /// |
| /// It's important to remember that [`char`] represents a Unicode Scalar |
| /// Value, and may not match your idea of what a 'character' is. Iteration |
| /// over grapheme clusters may be what you actually want. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let word = "goodbye"; |
| /// |
| /// let count = word.chars().count(); |
| /// assert_eq!(7, count); |
| /// |
| /// let mut chars = word.chars(); |
| /// |
| /// assert_eq!(Some('g'), chars.next()); |
| /// assert_eq!(Some('o'), chars.next()); |
| /// assert_eq!(Some('o'), chars.next()); |
| /// assert_eq!(Some('d'), chars.next()); |
| /// assert_eq!(Some('b'), chars.next()); |
| /// assert_eq!(Some('y'), chars.next()); |
| /// assert_eq!(Some('e'), chars.next()); |
| /// |
| /// assert_eq!(None, chars.next()); |
| /// ``` |
| /// |
| /// Remember, [`char`]s may not match your human intuition about characters: |
| /// |
| /// ``` |
| /// let y = "y̆"; |
| /// |
| /// let mut chars = y.chars(); |
| /// |
| /// assert_eq!(Some('y'), chars.next()); // not 'y̆' |
| /// assert_eq!(Some('\u{0306}'), chars.next()); |
| /// |
| /// assert_eq!(None, chars.next()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn chars(&self) -> Chars { |
| Chars{iter: self.as_bytes().iter()} |
| } |
| |
| /// Returns an iterator over the [`char`]s of a string slice, and their |
| /// positions. |
| /// |
| /// As a string slice consists of valid UTF-8, we can iterate through a |
| /// string slice by [`char`]. This method returns an iterator of both |
| /// these [`char`]s, as well as their byte positions. |
| /// |
| /// The iterator yields tuples. The position is first, the [`char`] is |
| /// second. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let word = "goodbye"; |
| /// |
| /// let count = word.char_indices().count(); |
| /// assert_eq!(7, count); |
| /// |
| /// let mut char_indices = word.char_indices(); |
| /// |
| /// assert_eq!(Some((0, 'g')), char_indices.next()); |
| /// assert_eq!(Some((1, 'o')), char_indices.next()); |
| /// assert_eq!(Some((2, 'o')), char_indices.next()); |
| /// assert_eq!(Some((3, 'd')), char_indices.next()); |
| /// assert_eq!(Some((4, 'b')), char_indices.next()); |
| /// assert_eq!(Some((5, 'y')), char_indices.next()); |
| /// assert_eq!(Some((6, 'e')), char_indices.next()); |
| /// |
| /// assert_eq!(None, char_indices.next()); |
| /// ``` |
| /// |
| /// Remember, [`char`]s may not match your human intuition about characters: |
| /// |
| /// ``` |
| /// let yes = "y̆es"; |
| /// |
| /// let mut char_indices = yes.char_indices(); |
| /// |
| /// assert_eq!(Some((0, 'y')), char_indices.next()); // not (0, 'y̆') |
| /// assert_eq!(Some((1, '\u{0306}')), char_indices.next()); |
| /// |
| /// // note the 3 here - the last character took up two bytes |
| /// assert_eq!(Some((3, 'e')), char_indices.next()); |
| /// assert_eq!(Some((4, 's')), char_indices.next()); |
| /// |
| /// assert_eq!(None, char_indices.next()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn char_indices(&self) -> CharIndices { |
| CharIndices { front_offset: 0, iter: self.chars() } |
| } |
| |
| /// An iterator over the bytes of a string slice. |
| /// |
| /// As a string slice consists of a sequence of bytes, we can iterate |
| /// through a string slice by byte. This method returns such an iterator. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let mut bytes = "bors".bytes(); |
| /// |
| /// assert_eq!(Some(b'b'), bytes.next()); |
| /// assert_eq!(Some(b'o'), bytes.next()); |
| /// assert_eq!(Some(b'r'), bytes.next()); |
| /// assert_eq!(Some(b's'), bytes.next()); |
| /// |
| /// assert_eq!(None, bytes.next()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn bytes(&self) -> Bytes { |
| Bytes(self.as_bytes().iter().cloned()) |
| } |
| |
| /// Split a string slice by whitespace. |
| /// |
| /// The iterator returned will return string slices that are sub-slices of |
| /// the original string slice, separated by any amount of whitespace. |
| /// |
| /// 'Whitespace' is defined according to the terms of the Unicode Derived |
| /// Core Property `White_Space`. If you only want to split on ASCII whitespace |
| /// instead, use [`split_ascii_whitespace`]. |
| /// |
| /// [`split_ascii_whitespace`]: #method.split_ascii_whitespace |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let mut iter = "A few words".split_whitespace(); |
| /// |
| /// assert_eq!(Some("A"), iter.next()); |
| /// assert_eq!(Some("few"), iter.next()); |
| /// assert_eq!(Some("words"), iter.next()); |
| /// |
| /// assert_eq!(None, iter.next()); |
| /// ``` |
| /// |
| /// All kinds of whitespace are considered: |
| /// |
| /// ``` |
| /// let mut iter = " Mary had\ta\u{2009}little \n\t lamb".split_whitespace(); |
| /// assert_eq!(Some("Mary"), iter.next()); |
| /// assert_eq!(Some("had"), iter.next()); |
| /// assert_eq!(Some("a"), iter.next()); |
| /// assert_eq!(Some("little"), iter.next()); |
| /// assert_eq!(Some("lamb"), iter.next()); |
| /// |
| /// assert_eq!(None, iter.next()); |
| /// ``` |
| #[stable(feature = "split_whitespace", since = "1.1.0")] |
| #[inline] |
| pub fn split_whitespace(&self) -> SplitWhitespace { |
| SplitWhitespace { inner: self.split(IsWhitespace).filter(IsNotEmpty) } |
| } |
| |
| /// Split a string slice by ASCII whitespace. |
| /// |
| /// The iterator returned will return string slices that are sub-slices of |
| /// the original string slice, separated by any amount of ASCII whitespace. |
| /// |
| /// To split by Unicode `Whitespace` instead, use [`split_whitespace`]. |
| /// |
| /// [`split_whitespace`]: #method.split_whitespace |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// #![feature(split_ascii_whitespace)] |
| /// let mut iter = "A few words".split_ascii_whitespace(); |
| /// |
| /// assert_eq!(Some("A"), iter.next()); |
| /// assert_eq!(Some("few"), iter.next()); |
| /// assert_eq!(Some("words"), iter.next()); |
| /// |
| /// assert_eq!(None, iter.next()); |
| /// ``` |
| /// |
| /// All kinds of ASCII whitespace are considered: |
| /// |
| /// ``` |
| /// let mut iter = " Mary had\ta little \n\t lamb".split_whitespace(); |
| /// assert_eq!(Some("Mary"), iter.next()); |
| /// assert_eq!(Some("had"), iter.next()); |
| /// assert_eq!(Some("a"), iter.next()); |
| /// assert_eq!(Some("little"), iter.next()); |
| /// assert_eq!(Some("lamb"), iter.next()); |
| /// |
| /// assert_eq!(None, iter.next()); |
| /// ``` |
| #[unstable(feature = "split_ascii_whitespace", issue = "48656")] |
| #[inline] |
| pub fn split_ascii_whitespace(&self) -> SplitAsciiWhitespace { |
| let inner = self |
| .as_bytes() |
| .split(IsAsciiWhitespace) |
| .filter(IsNotEmpty) |
| .map(UnsafeBytesToStr); |
| SplitAsciiWhitespace { inner } |
| } |
| |
| /// An iterator over the lines of a string, as string slices. |
| /// |
| /// Lines are ended with either a newline (`\n`) or a carriage return with |
| /// a line feed (`\r\n`). |
| /// |
| /// The final line ending is optional. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let text = "foo\r\nbar\n\nbaz\n"; |
| /// let mut lines = text.lines(); |
| /// |
| /// assert_eq!(Some("foo"), lines.next()); |
| /// assert_eq!(Some("bar"), lines.next()); |
| /// assert_eq!(Some(""), lines.next()); |
| /// assert_eq!(Some("baz"), lines.next()); |
| /// |
| /// assert_eq!(None, lines.next()); |
| /// ``` |
| /// |
| /// The final line ending isn't required: |
| /// |
| /// ``` |
| /// let text = "foo\nbar\n\r\nbaz"; |
| /// let mut lines = text.lines(); |
| /// |
| /// assert_eq!(Some("foo"), lines.next()); |
| /// assert_eq!(Some("bar"), lines.next()); |
| /// assert_eq!(Some(""), lines.next()); |
| /// assert_eq!(Some("baz"), lines.next()); |
| /// |
| /// assert_eq!(None, lines.next()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn lines(&self) -> Lines { |
| Lines(self.split_terminator('\n').map(LinesAnyMap)) |
| } |
| |
| /// An iterator over the lines of a string. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(since = "1.4.0", reason = "use lines() instead now")] |
| #[inline] |
| #[allow(deprecated)] |
| pub fn lines_any(&self) -> LinesAny { |
| LinesAny(self.lines()) |
| } |
| |
| /// Returns an iterator of `u16` over the string encoded as UTF-16. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let text = "Zażółć gęślą jaźń"; |
| /// |
| /// let utf8_len = text.len(); |
| /// let utf16_len = text.encode_utf16().count(); |
| /// |
| /// assert!(utf16_len <= utf8_len); |
| /// ``` |
| #[stable(feature = "encode_utf16", since = "1.8.0")] |
| pub fn encode_utf16(&self) -> EncodeUtf16 { |
| EncodeUtf16 { chars: self.chars(), extra: 0 } |
| } |
| |
| /// Returns `true` if the given pattern matches a sub-slice of |
| /// this string slice. |
| /// |
| /// Returns `false` if it does not. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let bananas = "bananas"; |
| /// |
| /// assert!(bananas.contains("nana")); |
| /// assert!(!bananas.contains("apples")); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn contains<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool { |
| pat.is_contained_in(self) |
| } |
| |
| /// Returns `true` if the given pattern matches a prefix of this |
| /// string slice. |
| /// |
| /// Returns `false` if it does not. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let bananas = "bananas"; |
| /// |
| /// assert!(bananas.starts_with("bana")); |
| /// assert!(!bananas.starts_with("nana")); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn starts_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool { |
| pat.is_prefix_of(self) |
| } |
| |
| /// Returns `true` if the given pattern matches a suffix of this |
| /// string slice. |
| /// |
| /// Returns `false` if it does not. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let bananas = "bananas"; |
| /// |
| /// assert!(bananas.ends_with("anas")); |
| /// assert!(!bananas.ends_with("nana")); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn ends_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| pat.is_suffix_of(self) |
| } |
| |
| /// Returns the byte index of the first character of this string slice that |
| /// matches the pattern. |
| /// |
| /// Returns [`None`] if the pattern doesn't match. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines if |
| /// a character matches. |
| /// |
| /// [`None`]: option/enum.Option.html#variant.None |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// |
| /// assert_eq!(s.find('L'), Some(0)); |
| /// assert_eq!(s.find('é'), Some(14)); |
| /// assert_eq!(s.find("Léopard"), Some(13)); |
| /// ``` |
| /// |
| /// More complex patterns using point-free style and closures: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// |
| /// assert_eq!(s.find(char::is_whitespace), Some(5)); |
| /// assert_eq!(s.find(char::is_lowercase), Some(1)); |
| /// assert_eq!(s.find(|c: char| c.is_whitespace() || c.is_lowercase()), Some(1)); |
| /// assert_eq!(s.find(|c: char| (c < 'o') && (c > 'a')), Some(4)); |
| /// ``` |
| /// |
| /// Not finding the pattern: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// let x: &[_] = &['1', '2']; |
| /// |
| /// assert_eq!(s.find(x), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> { |
| pat.into_searcher(self).next_match().map(|(i, _)| i) |
| } |
| |
| /// Returns the byte index of the last character of this string slice that |
| /// matches the pattern. |
| /// |
| /// Returns [`None`] if the pattern doesn't match. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines if |
| /// a character matches. |
| /// |
| /// [`None`]: option/enum.Option.html#variant.None |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// |
| /// assert_eq!(s.rfind('L'), Some(13)); |
| /// assert_eq!(s.rfind('é'), Some(14)); |
| /// ``` |
| /// |
| /// More complex patterns with closures: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// |
| /// assert_eq!(s.rfind(char::is_whitespace), Some(12)); |
| /// assert_eq!(s.rfind(char::is_lowercase), Some(20)); |
| /// ``` |
| /// |
| /// Not finding the pattern: |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// let x: &[_] = &['1', '2']; |
| /// |
| /// assert_eq!(s.rfind(x), None); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rfind<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| pat.into_searcher(self).next_match_back().map(|(i, _)| i) |
| } |
| |
| /// An iterator over substrings of this string slice, separated by |
| /// characters matched by a pattern. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines the |
| /// split. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator will be a [`DoubleEndedIterator`] if the pattern |
| /// allows a reverse search and forward/reverse search yields the same |
| /// elements. This is true for, eg, [`char`] but not for `&str`. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// If the pattern allows a reverse search but its results might differ |
| /// from a forward search, the [`rsplit`] method can be used. |
| /// |
| /// [`rsplit`]: #method.rsplit |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "Mary had a little lamb".split(' ').collect(); |
| /// assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]); |
| /// |
| /// let v: Vec<&str> = "".split('X').collect(); |
| /// assert_eq!(v, [""]); |
| /// |
| /// let v: Vec<&str> = "lionXXtigerXleopard".split('X').collect(); |
| /// assert_eq!(v, ["lion", "", "tiger", "leopard"]); |
| /// |
| /// let v: Vec<&str> = "lion::tiger::leopard".split("::").collect(); |
| /// assert_eq!(v, ["lion", "tiger", "leopard"]); |
| /// |
| /// let v: Vec<&str> = "abc1def2ghi".split(char::is_numeric).collect(); |
| /// assert_eq!(v, ["abc", "def", "ghi"]); |
| /// |
| /// let v: Vec<&str> = "lionXtigerXleopard".split(char::is_uppercase).collect(); |
| /// assert_eq!(v, ["lion", "tiger", "leopard"]); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "abc1defXghi".split(|c| c == '1' || c == 'X').collect(); |
| /// assert_eq!(v, ["abc", "def", "ghi"]); |
| /// ``` |
| /// |
| /// If a string contains multiple contiguous separators, you will end up |
| /// with empty strings in the output: |
| /// |
| /// ``` |
| /// let x = "||||a||b|c".to_string(); |
| /// let d: Vec<_> = x.split('|').collect(); |
| /// |
| /// assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]); |
| /// ``` |
| /// |
| /// Contiguous separators are separated by the empty string. |
| /// |
| /// ``` |
| /// let x = "(///)".to_string(); |
| /// let d: Vec<_> = x.split('/').collect(); |
| /// |
| /// assert_eq!(d, &["(", "", "", ")"]); |
| /// ``` |
| /// |
| /// Separators at the start or end of a string are neighbored |
| /// by empty strings. |
| /// |
| /// ``` |
| /// let d: Vec<_> = "010".split("0").collect(); |
| /// assert_eq!(d, &["", "1", ""]); |
| /// ``` |
| /// |
| /// When the empty string is used as a separator, it separates |
| /// every character in the string, along with the beginning |
| /// and end of the string. |
| /// |
| /// ``` |
| /// let f: Vec<_> = "rust".split("").collect(); |
| /// assert_eq!(f, &["", "r", "u", "s", "t", ""]); |
| /// ``` |
| /// |
| /// Contiguous separators can lead to possibly surprising behavior |
| /// when whitespace is used as the separator. This code is correct: |
| /// |
| /// ``` |
| /// let x = " a b c".to_string(); |
| /// let d: Vec<_> = x.split(' ').collect(); |
| /// |
| /// assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]); |
| /// ``` |
| /// |
| /// It does _not_ give you: |
| /// |
| /// ```,ignore |
| /// assert_eq!(d, &["a", "b", "c"]); |
| /// ``` |
| /// |
| /// Use [`split_whitespace`] for this behavior. |
| /// |
| /// [`split_whitespace`]: #method.split_whitespace |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn split<'a, P: Pattern<'a>>(&'a self, pat: P) -> Split<'a, P> { |
| Split(SplitInternal { |
| start: 0, |
| end: self.len(), |
| matcher: pat.into_searcher(self), |
| allow_trailing_empty: true, |
| finished: false, |
| }) |
| } |
| |
| /// An iterator over substrings of the given string slice, separated by |
| /// characters matched by a pattern and yielded in reverse order. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines the |
| /// split. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator requires that the pattern supports a reverse |
| /// search, and it will be a [`DoubleEndedIterator`] if a forward/reverse |
| /// search yields the same elements. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// For iterating from the front, the [`split`] method can be used. |
| /// |
| /// [`split`]: #method.split |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "Mary had a little lamb".rsplit(' ').collect(); |
| /// assert_eq!(v, ["lamb", "little", "a", "had", "Mary"]); |
| /// |
| /// let v: Vec<&str> = "".rsplit('X').collect(); |
| /// assert_eq!(v, [""]); |
| /// |
| /// let v: Vec<&str> = "lionXXtigerXleopard".rsplit('X').collect(); |
| /// assert_eq!(v, ["leopard", "tiger", "", "lion"]); |
| /// |
| /// let v: Vec<&str> = "lion::tiger::leopard".rsplit("::").collect(); |
| /// assert_eq!(v, ["leopard", "tiger", "lion"]); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "abc1defXghi".rsplit(|c| c == '1' || c == 'X').collect(); |
| /// assert_eq!(v, ["ghi", "def", "abc"]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rsplit<'a, P: Pattern<'a>>(&'a self, pat: P) -> RSplit<'a, P> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| RSplit(self.split(pat).0) |
| } |
| |
| /// An iterator over substrings of the given string slice, separated by |
| /// characters matched by a pattern. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines the |
| /// split. |
| /// |
| /// Equivalent to [`split`], except that the trailing substring |
| /// is skipped if empty. |
| /// |
| /// [`split`]: #method.split |
| /// |
| /// This method can be used for string data that is _terminated_, |
| /// rather than _separated_ by a pattern. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator will be a [`DoubleEndedIterator`] if the pattern |
| /// allows a reverse search and forward/reverse search yields the same |
| /// elements. This is true for, eg, [`char`] but not for `&str`. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// If the pattern allows a reverse search but its results might differ |
| /// from a forward search, the [`rsplit_terminator`] method can be used. |
| /// |
| /// [`rsplit_terminator`]: #method.rsplit_terminator |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "A.B.".split_terminator('.').collect(); |
| /// assert_eq!(v, ["A", "B"]); |
| /// |
| /// let v: Vec<&str> = "A..B..".split_terminator(".").collect(); |
| /// assert_eq!(v, ["A", "", "B", ""]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn split_terminator<'a, P: Pattern<'a>>(&'a self, pat: P) -> SplitTerminator<'a, P> { |
| SplitTerminator(SplitInternal { |
| allow_trailing_empty: false, |
| ..self.split(pat).0 |
| }) |
| } |
| |
| /// An iterator over substrings of `self`, separated by characters |
| /// matched by a pattern and yielded in reverse order. |
| /// |
| /// The pattern can be a simple `&str`, [`char`], or a closure that |
| /// determines the split. |
| /// Additional libraries might provide more complex patterns like |
| /// regular expressions. |
| /// |
| /// Equivalent to [`split`], except that the trailing substring is |
| /// skipped if empty. |
| /// |
| /// [`split`]: #method.split |
| /// |
| /// This method can be used for string data that is _terminated_, |
| /// rather than _separated_ by a pattern. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator requires that the pattern supports a |
| /// reverse search, and it will be double ended if a forward/reverse |
| /// search yields the same elements. |
| /// |
| /// For iterating from the front, the [`split_terminator`] method can be |
| /// used. |
| /// |
| /// [`split_terminator`]: #method.split_terminator |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "A.B.".rsplit_terminator('.').collect(); |
| /// assert_eq!(v, ["B", "A"]); |
| /// |
| /// let v: Vec<&str> = "A..B..".rsplit_terminator(".").collect(); |
| /// assert_eq!(v, ["", "B", "", "A"]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rsplit_terminator<'a, P: Pattern<'a>>(&'a self, pat: P) -> RSplitTerminator<'a, P> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| RSplitTerminator(self.split_terminator(pat).0) |
| } |
| |
| /// An iterator over substrings of the given string slice, separated by a |
| /// pattern, restricted to returning at most `n` items. |
| /// |
| /// If `n` substrings are returned, the last substring (the `n`th substring) |
| /// will contain the remainder of the string. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines the |
| /// split. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator will not be double ended, because it is |
| /// not efficient to support. |
| /// |
| /// If the pattern allows a reverse search, the [`rsplitn`] method can be |
| /// used. |
| /// |
| /// [`rsplitn`]: #method.rsplitn |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "Mary had a little lambda".splitn(3, ' ').collect(); |
| /// assert_eq!(v, ["Mary", "had", "a little lambda"]); |
| /// |
| /// let v: Vec<&str> = "lionXXtigerXleopard".splitn(3, "X").collect(); |
| /// assert_eq!(v, ["lion", "", "tigerXleopard"]); |
| /// |
| /// let v: Vec<&str> = "abcXdef".splitn(1, 'X').collect(); |
| /// assert_eq!(v, ["abcXdef"]); |
| /// |
| /// let v: Vec<&str> = "".splitn(1, 'X').collect(); |
| /// assert_eq!(v, [""]); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "abc1defXghi".splitn(2, |c| c == '1' || c == 'X').collect(); |
| /// assert_eq!(v, ["abc", "defXghi"]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn splitn<'a, P: Pattern<'a>>(&'a self, n: usize, pat: P) -> SplitN<'a, P> { |
| SplitN(SplitNInternal { |
| iter: self.split(pat).0, |
| count: n, |
| }) |
| } |
| |
| /// An iterator over substrings of this string slice, separated by a |
| /// pattern, starting from the end of the string, restricted to returning |
| /// at most `n` items. |
| /// |
| /// If `n` substrings are returned, the last substring (the `n`th substring) |
| /// will contain the remainder of the string. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that |
| /// determines the split. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator will not be double ended, because it is not |
| /// efficient to support. |
| /// |
| /// For splitting from the front, the [`splitn`] method can be used. |
| /// |
| /// [`splitn`]: #method.splitn |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "Mary had a little lamb".rsplitn(3, ' ').collect(); |
| /// assert_eq!(v, ["lamb", "little", "Mary had a"]); |
| /// |
| /// let v: Vec<&str> = "lionXXtigerXleopard".rsplitn(3, 'X').collect(); |
| /// assert_eq!(v, ["leopard", "tiger", "lionX"]); |
| /// |
| /// let v: Vec<&str> = "lion::tiger::leopard".rsplitn(2, "::").collect(); |
| /// assert_eq!(v, ["leopard", "lion::tiger"]); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "abc1defXghi".rsplitn(2, |c| c == '1' || c == 'X').collect(); |
| /// assert_eq!(v, ["ghi", "abc1def"]); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[inline] |
| pub fn rsplitn<'a, P: Pattern<'a>>(&'a self, n: usize, pat: P) -> RSplitN<'a, P> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| RSplitN(self.splitn(n, pat).0) |
| } |
| |
| /// An iterator over the disjoint matches of a pattern within the given string |
| /// slice. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that |
| /// determines if a character matches. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator will be a [`DoubleEndedIterator`] if the pattern |
| /// allows a reverse search and forward/reverse search yields the same |
| /// elements. This is true for, eg, [`char`] but not for `&str`. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// If the pattern allows a reverse search but its results might differ |
| /// from a forward search, the [`rmatches`] method can be used. |
| /// |
| /// [`rmatches`]: #method.rmatches |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "abcXXXabcYYYabc".matches("abc").collect(); |
| /// assert_eq!(v, ["abc", "abc", "abc"]); |
| /// |
| /// let v: Vec<&str> = "1abc2abc3".matches(char::is_numeric).collect(); |
| /// assert_eq!(v, ["1", "2", "3"]); |
| /// ``` |
| #[stable(feature = "str_matches", since = "1.2.0")] |
| #[inline] |
| pub fn matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> Matches<'a, P> { |
| Matches(MatchesInternal(pat.into_searcher(self))) |
| } |
| |
| /// An iterator over the disjoint matches of a pattern within this string slice, |
| /// yielded in reverse order. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines if |
| /// a character matches. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator requires that the pattern supports a reverse |
| /// search, and it will be a [`DoubleEndedIterator`] if a forward/reverse |
| /// search yields the same elements. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// For iterating from the front, the [`matches`] method can be used. |
| /// |
| /// [`matches`]: #method.matches |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let v: Vec<&str> = "abcXXXabcYYYabc".rmatches("abc").collect(); |
| /// assert_eq!(v, ["abc", "abc", "abc"]); |
| /// |
| /// let v: Vec<&str> = "1abc2abc3".rmatches(char::is_numeric).collect(); |
| /// assert_eq!(v, ["3", "2", "1"]); |
| /// ``` |
| #[stable(feature = "str_matches", since = "1.2.0")] |
| #[inline] |
| pub fn rmatches<'a, P: Pattern<'a>>(&'a self, pat: P) -> RMatches<'a, P> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| RMatches(self.matches(pat).0) |
| } |
| |
| /// An iterator over the disjoint matches of a pattern within this string |
| /// slice as well as the index that the match starts at. |
| /// |
| /// For matches of `pat` within `self` that overlap, only the indices |
| /// corresponding to the first match are returned. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines |
| /// if a character matches. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator will be a [`DoubleEndedIterator`] if the pattern |
| /// allows a reverse search and forward/reverse search yields the same |
| /// elements. This is true for, eg, [`char`] but not for `&str`. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// If the pattern allows a reverse search but its results might differ |
| /// from a forward search, the [`rmatch_indices`] method can be used. |
| /// |
| /// [`rmatch_indices`]: #method.rmatch_indices |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let v: Vec<_> = "abcXXXabcYYYabc".match_indices("abc").collect(); |
| /// assert_eq!(v, [(0, "abc"), (6, "abc"), (12, "abc")]); |
| /// |
| /// let v: Vec<_> = "1abcabc2".match_indices("abc").collect(); |
| /// assert_eq!(v, [(1, "abc"), (4, "abc")]); |
| /// |
| /// let v: Vec<_> = "ababa".match_indices("aba").collect(); |
| /// assert_eq!(v, [(0, "aba")]); // only the first `aba` |
| /// ``` |
| #[stable(feature = "str_match_indices", since = "1.5.0")] |
| #[inline] |
| pub fn match_indices<'a, P: Pattern<'a>>(&'a self, pat: P) -> MatchIndices<'a, P> { |
| MatchIndices(MatchIndicesInternal(pat.into_searcher(self))) |
| } |
| |
| /// An iterator over the disjoint matches of a pattern within `self`, |
| /// yielded in reverse order along with the index of the match. |
| /// |
| /// For matches of `pat` within `self` that overlap, only the indices |
| /// corresponding to the last match are returned. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines if a |
| /// character matches. |
| /// |
| /// # Iterator behavior |
| /// |
| /// The returned iterator requires that the pattern supports a reverse |
| /// search, and it will be a [`DoubleEndedIterator`] if a forward/reverse |
| /// search yields the same elements. |
| /// |
| /// [`DoubleEndedIterator`]: iter/trait.DoubleEndedIterator.html |
| /// |
| /// For iterating from the front, the [`match_indices`] method can be used. |
| /// |
| /// [`match_indices`]: #method.match_indices |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let v: Vec<_> = "abcXXXabcYYYabc".rmatch_indices("abc").collect(); |
| /// assert_eq!(v, [(12, "abc"), (6, "abc"), (0, "abc")]); |
| /// |
| /// let v: Vec<_> = "1abcabc2".rmatch_indices("abc").collect(); |
| /// assert_eq!(v, [(4, "abc"), (1, "abc")]); |
| /// |
| /// let v: Vec<_> = "ababa".rmatch_indices("aba").collect(); |
| /// assert_eq!(v, [(2, "aba")]); // only the last `aba` |
| /// ``` |
| #[stable(feature = "str_match_indices", since = "1.5.0")] |
| #[inline] |
| pub fn rmatch_indices<'a, P: Pattern<'a>>(&'a self, pat: P) -> RMatchIndices<'a, P> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| RMatchIndices(self.match_indices(pat).0) |
| } |
| |
| /// Returns a string slice with leading and trailing whitespace removed. |
| /// |
| /// 'Whitespace' is defined according to the terms of the Unicode Derived |
| /// Core Property `White_Space`. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = " Hello\tworld\t"; |
| /// |
| /// assert_eq!("Hello\tworld", s.trim()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn trim(&self) -> &str { |
| self.trim_matches(|c: char| c.is_whitespace()) |
| } |
| |
| /// Returns a string slice with leading whitespace removed. |
| /// |
| /// 'Whitespace' is defined according to the terms of the Unicode Derived |
| /// Core Property `White_Space`. |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. `start` in this context means the first |
| /// position of that byte string; for a left-to-right language like English or |
| /// Russian, this will be left side; and for right-to-left languages like |
| /// like Arabic or Hebrew, this will be the right side. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = " Hello\tworld\t"; |
| /// assert_eq!("Hello\tworld\t", s.trim_start()); |
| /// ``` |
| /// |
| /// Directionality: |
| /// |
| /// ``` |
| /// let s = " English "; |
| /// assert!(Some('E') == s.trim_start().chars().next()); |
| /// |
| /// let s = " עברית "; |
| /// assert!(Some('ע') == s.trim_start().chars().next()); |
| /// ``` |
| #[stable(feature = "trim_direction", since = "1.30.0")] |
| pub fn trim_start(&self) -> &str { |
| self.trim_start_matches(|c: char| c.is_whitespace()) |
| } |
| |
| /// Returns a string slice with trailing whitespace removed. |
| /// |
| /// 'Whitespace' is defined according to the terms of the Unicode Derived |
| /// Core Property `White_Space`. |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. `end` in this context means the last |
| /// position of that byte string; for a left-to-right language like English or |
| /// Russian, this will be right side; and for right-to-left languages like |
| /// like Arabic or Hebrew, this will be the left side. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = " Hello\tworld\t"; |
| /// assert_eq!(" Hello\tworld", s.trim_end()); |
| /// ``` |
| /// |
| /// Directionality: |
| /// |
| /// ``` |
| /// let s = " English "; |
| /// assert!(Some('h') == s.trim_end().chars().rev().next()); |
| /// |
| /// let s = " עברית "; |
| /// assert!(Some('ת') == s.trim_end().chars().rev().next()); |
| /// ``` |
| #[stable(feature = "trim_direction", since = "1.30.0")] |
| pub fn trim_end(&self) -> &str { |
| self.trim_end_matches(|c: char| c.is_whitespace()) |
| } |
| |
| /// Returns a string slice with leading whitespace removed. |
| /// |
| /// 'Whitespace' is defined according to the terms of the Unicode Derived |
| /// Core Property `White_Space`. |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. 'Left' in this context means the first |
| /// position of that byte string; for a language like Arabic or Hebrew |
| /// which are 'right to left' rather than 'left to right', this will be |
| /// the _right_ side, not the left. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = " Hello\tworld\t"; |
| /// |
| /// assert_eq!("Hello\tworld\t", s.trim_left()); |
| /// ``` |
| /// |
| /// Directionality: |
| /// |
| /// ``` |
| /// let s = " English"; |
| /// assert!(Some('E') == s.trim_left().chars().next()); |
| /// |
| /// let s = " עברית"; |
| /// assert!(Some('ע') == s.trim_left().chars().next()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(reason = "superseded by `trim_start`", since = "1.33.0")] |
| pub fn trim_left(&self) -> &str { |
| self.trim_start() |
| } |
| |
| /// Returns a string slice with trailing whitespace removed. |
| /// |
| /// 'Whitespace' is defined according to the terms of the Unicode Derived |
| /// Core Property `White_Space`. |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. 'Right' in this context means the last |
| /// position of that byte string; for a language like Arabic or Hebrew |
| /// which are 'right to left' rather than 'left to right', this will be |
| /// the _left_ side, not the right. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// let s = " Hello\tworld\t"; |
| /// |
| /// assert_eq!(" Hello\tworld", s.trim_right()); |
| /// ``` |
| /// |
| /// Directionality: |
| /// |
| /// ``` |
| /// let s = "English "; |
| /// assert!(Some('h') == s.trim_right().chars().rev().next()); |
| /// |
| /// let s = "עברית "; |
| /// assert!(Some('ת') == s.trim_right().chars().rev().next()); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(reason = "superseded by `trim_end`", since = "1.33.0")] |
| pub fn trim_right(&self) -> &str { |
| self.trim_end() |
| } |
| |
| /// Returns a string slice with all prefixes and suffixes that match a |
| /// pattern repeatedly removed. |
| /// |
| /// The pattern can be a [`char`] or a closure that determines if a |
| /// character matches. |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar"); |
| /// assert_eq!("123foo1bar123".trim_matches(char::is_numeric), "foo1bar"); |
| /// |
| /// let x: &[_] = &['1', '2']; |
| /// assert_eq!("12foo1bar12".trim_matches(x), "foo1bar"); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// assert_eq!("1foo1barXX".trim_matches(|c| c == '1' || c == 'X'), "foo1bar"); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn trim_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str |
| where P::Searcher: DoubleEndedSearcher<'a> |
| { |
| let mut i = 0; |
| let mut j = 0; |
| let mut matcher = pat.into_searcher(self); |
| if let Some((a, b)) = matcher.next_reject() { |
| i = a; |
| j = b; // Remember earliest known match, correct it below if |
| // last match is different |
| } |
| if let Some((_, b)) = matcher.next_reject_back() { |
| j = b; |
| } |
| unsafe { |
| // Searcher is known to return valid indices |
| self.get_unchecked(i..j) |
| } |
| } |
| |
| /// Returns a string slice with all prefixes that match a pattern |
| /// repeatedly removed. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines if |
| /// a character matches. |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. 'Left' in this context means the first |
| /// position of that byte string; for a language like Arabic or Hebrew |
| /// which are 'right to left' rather than 'left to right', this will be |
| /// the _right_ side, not the left. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// assert_eq!("11foo1bar11".trim_start_matches('1'), "foo1bar11"); |
| /// assert_eq!("123foo1bar123".trim_start_matches(char::is_numeric), "foo1bar123"); |
| /// |
| /// let x: &[_] = &['1', '2']; |
| /// assert_eq!("12foo1bar12".trim_start_matches(x), "foo1bar12"); |
| /// ``` |
| #[stable(feature = "trim_direction", since = "1.30.0")] |
| pub fn trim_start_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str { |
| let mut i = self.len(); |
| let mut matcher = pat.into_searcher(self); |
| if let Some((a, _)) = matcher.next_reject() { |
| i = a; |
| } |
| unsafe { |
| // Searcher is known to return valid indices |
| self.get_unchecked(i..self.len()) |
| } |
| } |
| |
| /// Returns a string slice with all suffixes that match a pattern |
| /// repeatedly removed. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that |
| /// determines if a character matches. |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. 'Right' in this context means the last |
| /// position of that byte string; for a language like Arabic or Hebrew |
| /// which are 'right to left' rather than 'left to right', this will be |
| /// the _left_ side, not the right. |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// assert_eq!("11foo1bar11".trim_end_matches('1'), "11foo1bar"); |
| /// assert_eq!("123foo1bar123".trim_end_matches(char::is_numeric), "123foo1bar"); |
| /// |
| /// let x: &[_] = &['1', '2']; |
| /// assert_eq!("12foo1bar12".trim_end_matches(x), "12foo1bar"); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// assert_eq!("1fooX".trim_end_matches(|c| c == '1' || c == 'X'), "1foo"); |
| /// ``` |
| #[stable(feature = "trim_direction", since = "1.30.0")] |
| pub fn trim_end_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| let mut j = 0; |
| let mut matcher = pat.into_searcher(self); |
| if let Some((_, b)) = matcher.next_reject_back() { |
| j = b; |
| } |
| unsafe { |
| // Searcher is known to return valid indices |
| self.get_unchecked(0..j) |
| } |
| } |
| |
| /// Returns a string slice with all prefixes that match a pattern |
| /// repeatedly removed. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that determines if |
| /// a character matches. |
| /// |
| /// [`char`]: primitive.char.html |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. 'Left' in this context means the first |
| /// position of that byte string; for a language like Arabic or Hebrew |
| /// which are 'right to left' rather than 'left to right', this will be |
| /// the _right_ side, not the left. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage: |
| /// |
| /// ``` |
| /// assert_eq!("11foo1bar11".trim_left_matches('1'), "foo1bar11"); |
| /// assert_eq!("123foo1bar123".trim_left_matches(char::is_numeric), "foo1bar123"); |
| /// |
| /// let x: &[_] = &['1', '2']; |
| /// assert_eq!("12foo1bar12".trim_left_matches(x), "foo1bar12"); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(reason = "superseded by `trim_start_matches`", since = "1.33.0")] |
| pub fn trim_left_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str { |
| self.trim_start_matches(pat) |
| } |
| |
| /// Returns a string slice with all suffixes that match a pattern |
| /// repeatedly removed. |
| /// |
| /// The pattern can be a `&str`, [`char`], or a closure that |
| /// determines if a character matches. |
| /// |
| /// [`char`]: primitive.char.html |
| /// |
| /// # Text directionality |
| /// |
| /// A string is a sequence of bytes. 'Right' in this context means the last |
| /// position of that byte string; for a language like Arabic or Hebrew |
| /// which are 'right to left' rather than 'left to right', this will be |
| /// the _left_ side, not the right. |
| /// |
| /// # Examples |
| /// |
| /// Simple patterns: |
| /// |
| /// ``` |
| /// assert_eq!("11foo1bar11".trim_right_matches('1'), "11foo1bar"); |
| /// assert_eq!("123foo1bar123".trim_right_matches(char::is_numeric), "123foo1bar"); |
| /// |
| /// let x: &[_] = &['1', '2']; |
| /// assert_eq!("12foo1bar12".trim_right_matches(x), "12foo1bar"); |
| /// ``` |
| /// |
| /// A more complex pattern, using a closure: |
| /// |
| /// ``` |
| /// assert_eq!("1fooX".trim_right_matches(|c| c == '1' || c == 'X'), "1foo"); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(reason = "superseded by `trim_end_matches`", since = "1.33.0")] |
| pub fn trim_right_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| self.trim_end_matches(pat) |
| } |
| |
| /// Parses this string slice into another type. |
| /// |
| /// Because `parse` is so general, it can cause problems with type |
| /// inference. As such, `parse` is one of the few times you'll see |
| /// the syntax affectionately known as the 'turbofish': `::<>`. This |
| /// helps the inference algorithm understand specifically which type |
| /// you're trying to parse into. |
| /// |
| /// `parse` can parse any type that implements the [`FromStr`] trait. |
| /// |
| /// [`FromStr`]: str/trait.FromStr.html |
| /// |
| /// # Errors |
| /// |
| /// Will return [`Err`] if it's not possible to parse this string slice into |
| /// the desired type. |
| /// |
| /// [`Err`]: str/trait.FromStr.html#associatedtype.Err |
| /// |
| /// # Examples |
| /// |
| /// Basic usage |
| /// |
| /// ``` |
| /// let four: u32 = "4".parse().unwrap(); |
| /// |
| /// assert_eq!(4, four); |
| /// ``` |
| /// |
| /// Using the 'turbofish' instead of annotating `four`: |
| /// |
| /// ``` |
| /// let four = "4".parse::<u32>(); |
| /// |
| /// assert_eq!(Ok(4), four); |
| /// ``` |
| /// |
| /// Failing to parse: |
| /// |
| /// ``` |
| /// let nope = "j".parse::<u32>(); |
| /// |
| /// assert!(nope.is_err()); |
| /// ``` |
| #[inline] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub fn parse<F: FromStr>(&self) -> Result<F, F::Err> { |
| FromStr::from_str(self) |
| } |
| |
| /// Checks if all characters in this string are within the ASCII range. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let ascii = "hello!\n"; |
| /// let non_ascii = "Grüße, Jürgen ❤"; |
| /// |
| /// assert!(ascii.is_ascii()); |
| /// assert!(!non_ascii.is_ascii()); |
| /// ``` |
| #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] |
| #[inline] |
| pub fn is_ascii(&self) -> bool { |
| // We can treat each byte as character here: all multibyte characters |
| // start with a byte that is not in the ascii range, so we will stop |
| // there already. |
| self.bytes().all(|b| b.is_ascii()) |
| } |
| |
| /// Checks that two strings are an ASCII case-insensitive match. |
| /// |
| /// Same as `to_ascii_lowercase(a) == to_ascii_lowercase(b)`, |
| /// but without allocating and copying temporaries. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// assert!("Ferris".eq_ignore_ascii_case("FERRIS")); |
| /// assert!("Ferrös".eq_ignore_ascii_case("FERRöS")); |
| /// assert!(!"Ferrös".eq_ignore_ascii_case("FERRÖS")); |
| /// ``` |
| #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] |
| #[inline] |
| pub fn eq_ignore_ascii_case(&self, other: &str) -> bool { |
| self.as_bytes().eq_ignore_ascii_case(other.as_bytes()) |
| } |
| |
| /// Converts this string 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`]. |
| /// |
| /// [`to_ascii_uppercase`]: #method.to_ascii_uppercase |
| #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] |
| pub fn make_ascii_uppercase(&mut self) { |
| let me = unsafe { self.as_bytes_mut() }; |
| me.make_ascii_uppercase() |
| } |
| |
| /// Converts this string 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`]. |
| /// |
| /// [`to_ascii_lowercase`]: #method.to_ascii_lowercase |
| #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")] |
| pub fn make_ascii_lowercase(&mut self) { |
| let me = unsafe { self.as_bytes_mut() }; |
| me.make_ascii_lowercase() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl AsRef<[u8]> for str { |
| #[inline] |
| fn as_ref(&self) -> &[u8] { |
| self.as_bytes() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl Default for &str { |
| /// Creates an empty str |
| fn default() -> Self { "" } |
| } |
| |
| #[stable(feature = "default_mut_str", since = "1.28.0")] |
| impl Default for &mut str { |
| /// Creates an empty mutable str |
| fn default() -> Self { unsafe { from_utf8_unchecked_mut(&mut []) } } |
| } |
| |
| /// An iterator over the non-whitespace substrings of a string, |
| /// separated by any amount of whitespace. |
| /// |
| /// This struct is created by the [`split_whitespace`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`split_whitespace`]: ../../std/primitive.str.html#method.split_whitespace |
| /// [`str`]: ../../std/primitive.str.html |
| #[stable(feature = "split_whitespace", since = "1.1.0")] |
| #[derive(Clone, Debug)] |
| pub struct SplitWhitespace<'a> { |
| inner: Filter<Split<'a, IsWhitespace>, IsNotEmpty>, |
| } |
| |
| /// An iterator over the non-ASCII-whitespace substrings of a string, |
| /// separated by any amount of ASCII whitespace. |
| /// |
| /// This struct is created by the [`split_ascii_whitespace`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`split_ascii_whitespace`]: ../../std/primitive.str.html#method.split_ascii_whitespace |
| /// [`str`]: ../../std/primitive.str.html |
| #[unstable(feature = "split_ascii_whitespace", issue = "48656")] |
| #[derive(Clone, Debug)] |
| pub struct SplitAsciiWhitespace<'a> { |
| inner: Map<Filter<SliceSplit<'a, u8, IsAsciiWhitespace>, IsNotEmpty>, UnsafeBytesToStr>, |
| } |
| |
| #[derive(Clone)] |
| struct IsWhitespace; |
| |
| impl FnOnce<(char, )> for IsWhitespace { |
| type Output = bool; |
| |
| #[inline] |
| extern "rust-call" fn call_once(mut self, arg: (char, )) -> bool { |
| self.call_mut(arg) |
| } |
| } |
| |
| impl FnMut<(char, )> for IsWhitespace { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, arg: (char, )) -> bool { |
| arg.0.is_whitespace() |
| } |
| } |
| |
| #[derive(Clone)] |
| struct IsAsciiWhitespace; |
| |
| impl<'a> FnOnce<(&'a u8, )> for IsAsciiWhitespace { |
| type Output = bool; |
| |
| #[inline] |
| extern "rust-call" fn call_once(mut self, arg: (&u8, )) -> bool { |
| self.call_mut(arg) |
| } |
| } |
| |
| impl<'a> FnMut<(&'a u8, )> for IsAsciiWhitespace { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, arg: (&u8, )) -> bool { |
| arg.0.is_ascii_whitespace() |
| } |
| } |
| |
| #[derive(Clone)] |
| struct IsNotEmpty; |
| |
| impl<'a, 'b> FnOnce<(&'a &'b str, )> for IsNotEmpty { |
| type Output = bool; |
| |
| #[inline] |
| extern "rust-call" fn call_once(mut self, arg: (&'a &'b str, )) -> bool { |
| self.call_mut(arg) |
| } |
| } |
| |
| impl<'a, 'b> FnMut<(&'a &'b str, )> for IsNotEmpty { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, arg: (&'a &'b str, )) -> bool { |
| !arg.0.is_empty() |
| } |
| } |
| |
| impl<'a, 'b> FnOnce<(&'a &'b [u8], )> for IsNotEmpty { |
| type Output = bool; |
| |
| #[inline] |
| extern "rust-call" fn call_once(mut self, arg: (&'a &'b [u8], )) -> bool { |
| self.call_mut(arg) |
| } |
| } |
| |
| impl<'a, 'b> FnMut<(&'a &'b [u8], )> for IsNotEmpty { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, arg: (&'a &'b [u8], )) -> bool { |
| !arg.0.is_empty() |
| } |
| } |
| |
| #[derive(Clone)] |
| struct UnsafeBytesToStr; |
| |
| impl<'a> FnOnce<(&'a [u8], )> for UnsafeBytesToStr { |
| type Output = &'a str; |
| |
| #[inline] |
| extern "rust-call" fn call_once(mut self, arg: (&'a [u8], )) -> &'a str { |
| self.call_mut(arg) |
| } |
| } |
| |
| impl<'a> FnMut<(&'a [u8], )> for UnsafeBytesToStr { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, arg: (&'a [u8], )) -> &'a str { |
| unsafe { from_utf8_unchecked(arg.0) } |
| } |
| } |
| |
| |
| #[stable(feature = "split_whitespace", since = "1.1.0")] |
| impl<'a> Iterator for SplitWhitespace<'a> { |
| type Item = &'a str; |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.inner.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.inner.size_hint() |
| } |
| } |
| |
| #[stable(feature = "split_whitespace", since = "1.1.0")] |
| impl<'a> DoubleEndedIterator for SplitWhitespace<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> { |
| self.inner.next_back() |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl FusedIterator for SplitWhitespace<'_> {} |
| |
| #[unstable(feature = "split_ascii_whitespace", issue = "48656")] |
| impl<'a> Iterator for SplitAsciiWhitespace<'a> { |
| type Item = &'a str; |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.inner.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.inner.size_hint() |
| } |
| } |
| |
| #[unstable(feature = "split_ascii_whitespace", issue = "48656")] |
| impl<'a> DoubleEndedIterator for SplitAsciiWhitespace<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> { |
| self.inner.next_back() |
| } |
| } |
| |
| #[unstable(feature = "split_ascii_whitespace", issue = "48656")] |
| impl FusedIterator for SplitAsciiWhitespace<'_> {} |
| |
| /// An iterator of [`u16`] over the string encoded as UTF-16. |
| /// |
| /// [`u16`]: ../../std/primitive.u16.html |
| /// |
| /// This struct is created by the [`encode_utf16`] method on [`str`]. |
| /// See its documentation for more. |
| /// |
| /// [`encode_utf16`]: ../../std/primitive.str.html#method.encode_utf16 |
| /// [`str`]: ../../std/primitive.str.html |
| #[derive(Clone)] |
| #[stable(feature = "encode_utf16", since = "1.8.0")] |
| pub struct EncodeUtf16<'a> { |
| chars: Chars<'a>, |
| extra: u16, |
| } |
| |
| #[stable(feature = "collection_debug", since = "1.17.0")] |
| impl fmt::Debug for EncodeUtf16<'_> { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| f.pad("EncodeUtf16 { .. }") |
| } |
| } |
| |
| #[stable(feature = "encode_utf16", since = "1.8.0")] |
| impl<'a> Iterator for EncodeUtf16<'a> { |
| type Item = u16; |
| |
| #[inline] |
| fn next(&mut self) -> Option<u16> { |
| if self.extra != 0 { |
| let tmp = self.extra; |
| self.extra = 0; |
| return Some(tmp); |
| } |
| |
| let mut buf = [0; 2]; |
| self.chars.next().map(|ch| { |
| let n = ch.encode_utf16(&mut buf).len(); |
| if n == 2 { |
| self.extra = buf[1]; |
| } |
| buf[0] |
| }) |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let (low, high) = self.chars.size_hint(); |
| // every char gets either one u16 or two u16, |
| // so this iterator is between 1 or 2 times as |
| // long as the underlying iterator. |
| (low, high.and_then(|n| n.checked_mul(2))) |
| } |
| } |
| |
| #[stable(feature = "fused", since = "1.26.0")] |
| impl FusedIterator for EncodeUtf16<'_> {} |