// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! 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}; use mem; pub mod pattern; #[unstable(feature = "str_internals", issue = "0")] #[allow(missing_docs)] pub mod lossy; /// A trait to abstract the idea of creating a new instance of a type 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 /// /// # 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 { /// let coords: Vec<&str> = s.trim_matches(|p| p == '(' || p == ')' ) /// .split(",") /// .collect(); /// /// let x_fromstr = coords[0].parse::()?; /// let y_fromstr = coords[1].parse::()?; /// /// 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; } #[stable(feature = "rust1", since = "1.0.0")] impl FromStr for bool { type Err = ParseBoolError; /// Parse a `bool` from a string. /// /// Yields a `Result`, 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!(::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::().is_err()); /// ``` #[inline] fn from_str(s: &str) -> Result { 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(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, } 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) in case of lossy decoding. #[stable(feature = "utf8_error_error_len", since = "1.20.0")] pub fn error_len(&self) -> Option { 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) }) } /// Forms a str from a pointer and a length. /// /// The `len` argument is the number of bytes in the string. /// /// # Safety /// /// This function is unsafe as there is no guarantee that the given pointer is /// valid for `len` bytes, nor whether the lifetime inferred is a suitable /// lifetime for the returned str. /// /// The data must be valid UTF-8 /// /// `p` must be non-null, even for zero-length strs, because non-zero bits /// are required to distinguish between a zero-length str within `Some()` /// from `None`. `p` can be a bogus non-dereferencable pointer, such as `0x1`, /// for zero-length strs, though. /// /// # Caveat /// /// The lifetime for the returned str is inferred from its usage. To /// prevent accidental misuse, it's suggested to tie the lifetime to whichever /// source lifetime is safe in the context, such as by providing a helper /// function taking the lifetime of a host value for the str, or by explicit /// annotation. /// Performs the same functionality as `from_raw_parts`, except that a mutable /// str is returned. /// unsafe fn from_raw_parts_mut<'a>(p: *mut u8, len: usize) -> &'a mut str { from_utf8_unchecked_mut(slice::from_raw_parts_mut(p, len)) } /// 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>(bytes: &mut I) -> Option { // 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 where I: DoubleEndedIterator, { // Decode UTF-8 let w = match bytes.next_back() { None => return None, Some(&next_byte) if next_byte < 128 => return Some(next_byte as u32), Some(&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 { 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) { 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 { // 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 { 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<'a> FusedIterator for Chars<'a> {} 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) { 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)> { match self.iter.next_back() { None => None, Some(ch) => { let index = self.front_offset + self.iter.iter.len(); Some((index, ch)) } } } } #[stable(feature = "fused", since = "1.26.0")] impl<'a> FusedIterator for CharIndices<'a> {} 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>); #[stable(feature = "rust1", since = "1.0.0")] impl<'a> Iterator for Bytes<'a> { type Item = u8; #[inline] fn next(&mut self) -> Option { self.0.next() } #[inline] fn size_hint(&self) -> (usize, Option) { self.0.size_hint() } #[inline] fn count(self) -> usize { self.0.count() } #[inline] fn last(self) -> Option { self.0.last() } #[inline] fn nth(&mut self, n: usize) -> Option { self.0.nth(n) } #[inline] fn all(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool { self.0.all(f) } #[inline] fn any(&mut self, f: F) -> bool where F: FnMut(Self::Item) -> bool { self.0.any(f) } #[inline] fn find

(&mut self, predicate: P) -> Option where P: FnMut(&Self::Item) -> bool { self.0.find(predicate) } #[inline] fn position

(&mut self, predicate: P) -> Option where P: FnMut(Self::Item) -> bool { self.0.position(predicate) } #[inline] fn rposition

(&mut self, predicate: P) -> Option where P: FnMut(Self::Item) -> bool { self.0.rposition(predicate) } } #[stable(feature = "rust1", since = "1.0.0")] impl<'a> DoubleEndedIterator for Bytes<'a> { #[inline] fn next_back(&mut self) -> Option { self.0.next_back() } #[inline] fn rfind

(&mut self, predicate: P) -> Option where P: FnMut(&Self::Item) -> bool { self.0.rfind(predicate) } } #[stable(feature = "rust1", since = "1.0.0")] impl<'a> ExactSizeIterator for Bytes<'a> { #[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<'a> FusedIterator for Bytes<'a> {} #[unstable(feature = "trusted_len", issue = "37572")] unsafe impl<'a> TrustedLen for Bytes<'a> {} #[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().slice_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.slice_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.slice_unchecked(b, self.end); self.end = a; Some(elt) }, None => unsafe { self.finished = true; Some(haystack.slice_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().slice_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().slice_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().slice_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().slice_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, 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) { 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<'a> FusedIterator for Lines<'a> {} /// 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) { 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<'a> FusedIterator for LinesAny<'a> {} /* 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 `iter` checking that it's a valid UTF-8 sequence, /// returning `true` in that case, or, if it is invalid, `false` with /// `iter` reset such that it is pointing at the first byte in the /// invalid sequence. #[inline] fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> { let mut index = 0; let len = v.len(); let usize_bytes = mem::size_of::(); 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.offset(index as isize).align_offset(usize_bytes) }; if align == 0 { while index < blocks_end { unsafe { let block = ptr.offset(index as isize) 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 { return 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 { 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> for str { type Output = str; #[inline] fn index(&self, index: ops::Range) -> &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> for str { #[inline] fn index_mut(&mut self, index: ops::Range) -> &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> for str { type Output = str; #[inline] fn index(&self, index: ops::RangeTo) -> &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> for str { #[inline] fn index_mut(&mut self, index: ops::RangeTo) -> &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> for str { type Output = str; #[inline] fn index(&self, index: ops::RangeFrom) -> &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> for str { #[inline] fn index_mut(&mut self, index: ops::RangeFrom) -> &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 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 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> for str { type Output = str; #[inline] fn index(&self, index: ops::RangeInclusive) -> &str { index.index(self) } } #[stable(feature = "inclusive_range", since = "1.26.0")] impl ops::Index> for str { type Output = str; #[inline] fn index(&self, index: ops::RangeToInclusive) -> &str { index.index(self) } } #[stable(feature = "inclusive_range", since = "1.26.0")] impl ops::IndexMut> for str { #[inline] fn index_mut(&mut self, index: ops::RangeInclusive) -> &mut str { index.index_mut(self) } } #[stable(feature = "inclusive_range", since = "1.26.0")] impl ops::IndexMut> for str { #[inline] fn index_mut(&mut self, index: ops::RangeToInclusive) -> &mut str { index.index_mut(self) } } #[stable(feature = "str_checked_slicing", since = "1.20.0")] impl SliceIndex 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 for ops::Range { 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().offset(self.start as isize); 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().offset(self.start as isize); 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()] // canot 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 for ops::RangeTo { 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 for ops::RangeFrom { 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().offset(self.start as isize); 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().offset(self.start as isize); 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 for ops::RangeInclusive { type Output = str; #[inline] fn get(self, slice: &str) -> Option<&Self::Output> { if let Some(end) = self.end.checked_add(1) { (self.start..end).get(slice) } else { None } } #[inline] fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { if let Some(end) = self.end.checked_add(1) { (self.start..end).get_mut(slice) } else { None } } #[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 { assert!(self.end != usize::max_value(), "attempted to index str up to maximum usize"); (self.start..self.end+1).index(slice) } #[inline] fn index_mut(self, slice: &mut str) -> &mut Self::Output { assert!(self.end != usize::max_value(), "attempted to index str up to maximum usize"); (self.start..self.end+1).index_mut(slice) } } #[stable(feature = "inclusive_range", since = "1.26.0")] impl SliceIndex for ops::RangeToInclusive { type Output = str; #[inline] fn get(self, slice: &str) -> Option<&Self::Output> { if self.end < usize::max_value() && slice.is_char_boundary(self.end + 1) { Some(unsafe { self.get_unchecked(slice) }) } else { None } } #[inline] fn get_mut(self, slice: &mut str) -> Option<&mut Self::Output> { if self.end < usize::max_value() && slice.is_char_boundary(self.end + 1) { 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 + 1)) } #[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 + 1)) } #[inline] fn index(self, slice: &str) -> &Self::Output { assert!(self.end != usize::max_value(), "attempted to index str up to maximum usize"); (..self.end+1).index(slice) } #[inline] fn index_mut(self, slice: &mut str) -> &mut Self::Output { assert!(self.end != usize::max_value(), "attempted to index str up to maximum usize"); (..self.end+1).index_mut(slice) } } } public_in_stage0! { { /// Methods for string slices #[allow(missing_docs)] #[doc(hidden)] #[unstable(feature = "core_str_ext", reason = "stable interface provided by `impl str` in later crates", issue = "32110")] } trait StrExt { // NB there are no docs here are they're all located on the StrExt trait in // liballoc, not here. #[stable(feature = "core", since = "1.6.0")] fn contains<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool; #[stable(feature = "core", since = "1.6.0")] fn chars(&self) -> Chars; #[stable(feature = "core", since = "1.6.0")] fn bytes(&self) -> Bytes; #[stable(feature = "core", since = "1.6.0")] fn char_indices(&self) -> CharIndices; #[stable(feature = "core", since = "1.6.0")] fn split<'a, P: Pattern<'a>>(&'a self, pat: P) -> Split<'a, P>; #[stable(feature = "core", since = "1.6.0")] fn rsplit<'a, P: Pattern<'a>>(&'a self, pat: P) -> RSplit<'a, P> where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn splitn<'a, P: Pattern<'a>>(&'a self, count: usize, pat: P) -> SplitN<'a, P>; #[stable(feature = "core", since = "1.6.0")] fn rsplitn<'a, P: Pattern<'a>>(&'a self, count: usize, pat: P) -> RSplitN<'a, P> where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn split_terminator<'a, P: Pattern<'a>>(&'a self, pat: P) -> SplitTerminator<'a, P>; #[stable(feature = "core", since = "1.6.0")] fn rsplit_terminator<'a, P: Pattern<'a>>(&'a self, pat: P) -> RSplitTerminator<'a, P> where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> Matches<'a, P>; #[stable(feature = "core", since = "1.6.0")] fn rmatches<'a, P: Pattern<'a>>(&'a self, pat: P) -> RMatches<'a, P> where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn match_indices<'a, P: Pattern<'a>>(&'a self, pat: P) -> MatchIndices<'a, P>; #[stable(feature = "core", since = "1.6.0")] fn rmatch_indices<'a, P: Pattern<'a>>(&'a self, pat: P) -> RMatchIndices<'a, P> where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn lines(&self) -> Lines; #[stable(feature = "core", since = "1.6.0")] #[rustc_deprecated(since = "1.6.0", reason = "use lines() instead now")] #[allow(deprecated)] fn lines_any(&self) -> LinesAny; #[stable(feature = "str_checked_slicing", since = "1.20.0")] fn get>(&self, i: I) -> Option<&I::Output>; #[stable(feature = "str_checked_slicing", since = "1.20.0")] fn get_mut>(&mut self, i: I) -> Option<&mut I::Output>; #[stable(feature = "str_checked_slicing", since = "1.20.0")] unsafe fn get_unchecked>(&self, i: I) -> &I::Output; #[stable(feature = "str_checked_slicing", since = "1.20.0")] unsafe fn get_unchecked_mut>(&mut self, i: I) -> &mut I::Output; #[stable(feature = "core", since = "1.6.0")] unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str; #[stable(feature = "core", since = "1.6.0")] unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str; #[stable(feature = "core", since = "1.6.0")] fn starts_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool; #[stable(feature = "core", since = "1.6.0")] fn ends_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn trim_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str where P::Searcher: DoubleEndedSearcher<'a>; #[stable(feature = "core", since = "1.6.0")] fn trim_left_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str; #[stable(feature = "core", since = "1.6.0")] fn trim_right_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str where P::Searcher: ReverseSearcher<'a>; #[stable(feature = "is_char_boundary", since = "1.9.0")] fn is_char_boundary(&self, index: usize) -> bool; #[stable(feature = "core", since = "1.6.0")] fn as_bytes(&self) -> &[u8]; #[stable(feature = "str_mut_extras", since = "1.20.0")] unsafe fn as_bytes_mut(&mut self) -> &mut [u8]; #[stable(feature = "core", since = "1.6.0")] fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option; #[stable(feature = "core", since = "1.6.0")] fn rfind<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option where P::Searcher: ReverseSearcher<'a>; fn find_str<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option; #[stable(feature = "core", since = "1.6.0")] fn split_at(&self, mid: usize) -> (&str, &str); #[stable(feature = "core", since = "1.6.0")] fn split_at_mut(&mut self, mid: usize) -> (&mut str, &mut str); #[stable(feature = "core", since = "1.6.0")] fn as_ptr(&self) -> *const u8; #[stable(feature = "core", since = "1.6.0")] fn len(&self) -> usize; #[stable(feature = "core", since = "1.6.0")] fn is_empty(&self) -> bool; #[stable(feature = "core", since = "1.6.0")] fn parse(&self) -> Result; #[stable(feature = "split_whitespace", since = "1.1.0")] fn split_whitespace<'a>(&'a self) -> SplitWhitespace<'a>; #[stable(feature = "rust1", since = "1.0.0")] fn trim(&self) -> &str; #[stable(feature = "rust1", since = "1.0.0")] fn trim_left(&self) -> &str; #[stable(feature = "rust1", since = "1.0.0")] fn trim_right(&self) -> &str; }} // 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); } #[stable(feature = "core", since = "1.6.0")] impl StrExt for str { #[inline] fn contains<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool { pat.is_contained_in(self) } #[inline] fn chars(&self) -> Chars { Chars{iter: self.as_bytes().iter()} } #[inline] fn bytes(&self) -> Bytes { Bytes(self.as_bytes().iter().cloned()) } #[inline] fn char_indices(&self) -> CharIndices { CharIndices { front_offset: 0, iter: self.chars() } } #[inline] 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, }) } #[inline] fn rsplit<'a, P: Pattern<'a>>(&'a self, pat: P) -> RSplit<'a, P> where P::Searcher: ReverseSearcher<'a> { RSplit(self.split(pat).0) } #[inline] fn splitn<'a, P: Pattern<'a>>(&'a self, count: usize, pat: P) -> SplitN<'a, P> { SplitN(SplitNInternal { iter: self.split(pat).0, count, }) } #[inline] fn rsplitn<'a, P: Pattern<'a>>(&'a self, count: usize, pat: P) -> RSplitN<'a, P> where P::Searcher: ReverseSearcher<'a> { RSplitN(self.splitn(count, pat).0) } #[inline] fn split_terminator<'a, P: Pattern<'a>>(&'a self, pat: P) -> SplitTerminator<'a, P> { SplitTerminator(SplitInternal { allow_trailing_empty: false, ..self.split(pat).0 }) } #[inline] 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) } #[inline] fn matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> Matches<'a, P> { Matches(MatchesInternal(pat.into_searcher(self))) } #[inline] fn rmatches<'a, P: Pattern<'a>>(&'a self, pat: P) -> RMatches<'a, P> where P::Searcher: ReverseSearcher<'a> { RMatches(self.matches(pat).0) } #[inline] fn match_indices<'a, P: Pattern<'a>>(&'a self, pat: P) -> MatchIndices<'a, P> { MatchIndices(MatchIndicesInternal(pat.into_searcher(self))) } #[inline] 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) } #[inline] fn lines(&self) -> Lines { Lines(self.split_terminator('\n').map(LinesAnyMap)) } #[inline] #[allow(deprecated)] fn lines_any(&self) -> LinesAny { LinesAny(self.lines()) } #[inline] fn get>(&self, i: I) -> Option<&I::Output> { i.get(self) } #[inline] fn get_mut>(&mut self, i: I) -> Option<&mut I::Output> { i.get_mut(self) } #[inline] unsafe fn get_unchecked>(&self, i: I) -> &I::Output { i.get_unchecked(self) } #[inline] unsafe fn get_unchecked_mut>(&mut self, i: I) -> &mut I::Output { i.get_unchecked_mut(self) } #[inline] unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str { (begin..end).get_unchecked(self) } #[inline] unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str { (begin..end).get_unchecked_mut(self) } #[inline] fn starts_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool { pat.is_prefix_of(self) } #[inline] fn ends_with<'a, P: Pattern<'a>>(&'a self, pat: P) -> bool where P::Searcher: ReverseSearcher<'a> { pat.is_suffix_of(self) } #[inline] 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.slice_unchecked(i, j) } } #[inline] fn trim_left_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.slice_unchecked(i, self.len()) } } #[inline] fn trim_right_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.slice_unchecked(0, j) } } #[inline] 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, } } #[inline] fn as_bytes(&self) -> &[u8] { unsafe { &*(self as *const str as *const [u8]) } } #[inline] unsafe fn as_bytes_mut(&mut self) -> &mut [u8] { &mut *(self as *mut str as *mut [u8]) } fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option { pat.into_searcher(self).next_match().map(|(i, _)| i) } fn rfind<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option where P::Searcher: ReverseSearcher<'a> { pat.into_searcher(self).next_match_back().map(|(i, _)| i) } fn find_str<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option { self.find(pat) } #[inline] 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.slice_unchecked(0, mid), self.slice_unchecked(mid, self.len())) } } else { slice_error_fail(self, 0, mid) } } 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_raw_parts_mut(ptr, mid), from_raw_parts_mut(ptr.offset(mid as isize), len - mid)) } } else { slice_error_fail(self, 0, mid) } } #[inline] fn as_ptr(&self) -> *const u8 { self as *const str as *const u8 } #[inline] fn len(&self) -> usize { self.as_bytes().len() } #[inline] fn is_empty(&self) -> bool { self.len() == 0 } #[inline] fn parse(&self) -> Result { FromStr::from_str(self) } #[inline] fn split_whitespace(&self) -> SplitWhitespace { SplitWhitespace { inner: self.split(IsWhitespace).filter(IsNotEmpty) } } #[inline] fn trim(&self) -> &str { self.trim_matches(|c: char| c.is_whitespace()) } #[inline] fn trim_left(&self) -> &str { self.trim_left_matches(|c: char| c.is_whitespace()) } #[inline] fn trim_right(&self) -> &str { self.trim_right_matches(|c: char| c.is_whitespace()) } } // FIXME: remove (inline) this macro and the SliceExt trait // when updating to a bootstrap compiler that has the new lang items. #[cfg_attr(stage0, macro_export)] #[unstable(feature = "core_str_ext", issue = "32110")] macro_rules! str_core_methods { () => { /// 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. /// /// [`char`]: primitive.char.html /// /// # 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] pub fn len(&self) -> usize { StrExt::len(self) } /// 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")] pub fn is_empty(&self) -> bool { StrExt::is_empty(self) } /// 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 { StrExt::is_char_boundary(self, index) } /// 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)] pub fn as_bytes(&self) -> &[u8] { StrExt::as_bytes(self) } /// 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] { StrExt::as_bytes_mut(self) } /// 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 fn as_ptr(&self) -> *const u8 { StrExt::as_ptr(self) } /// 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>(&self, i: I) -> Option<&I::Output> { StrExt::get(self, i) } /// 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>(&mut self, i: I) -> Option<&mut I::Output> { StrExt::get_mut(self, i) } /// 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>(&self, i: I) -> &I::Output { StrExt::get_unchecked(self, i) } /// 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>(&mut self, i: I) -> &mut I::Output { StrExt::get_unchecked_mut(self, i) } /// 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")] #[inline] pub unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str { StrExt::slice_unchecked(self, begin, end) } /// 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")] #[inline] pub unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str { StrExt::slice_mut_unchecked(self, begin, end) } /// 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) { StrExt::split_at(self, 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) { StrExt::split_at_mut(self, 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. /// /// [`char`]: primitive.char.html /// /// # 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 { StrExt::chars(self) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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 { StrExt::char_indices(self) } /// 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 { StrExt::bytes(self) } /// 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`. /// /// # 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 { StrExt::split_whitespace(self) } /// 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 { StrExt::lines(self) } /// 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 { StrExt::lines_any(self) } /// 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::new(self) } /// 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 { StrExt::contains(self, pat) } /// 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 { StrExt::starts_with(self, pat) } /// 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> { StrExt::ends_with(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// [`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 { StrExt::find(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// [`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 where P::Searcher: ReverseSearcher<'a> { StrExt::rfind(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// [`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> { StrExt::split(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::rsplit(self, pat) } /// 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 /// [`char`]: primitive.char.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> { StrExt::split_terminator(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// 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> { StrExt::rsplit_terminator(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::splitn(self, n, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::rsplitn(self, n, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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 /// [`char`]: primitive.char.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> { StrExt::matches(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::rmatches(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::match_indices(self, pat) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::rmatch_indices(self, pat) } /// 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 { StrExt::trim(self) } /// 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")] pub fn trim_left(&self) -> &str { StrExt::trim_left(self) } /// 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")] pub fn trim_right(&self) -> &str { StrExt::trim_right(self) } /// 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. /// /// [`char`]: primitive.char.html /// /// # 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> { StrExt::trim_matches(self, pat) } /// 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")] pub fn trim_left_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str { StrExt::trim_left_matches(self, 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")] pub fn trim_right_matches<'a, P: Pattern<'a>>(&'a self, pat: P) -> &'a str where P::Searcher: ReverseSearcher<'a> { StrExt::trim_right_matches(self, 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::(); /// /// assert_eq!(Ok(4), four); /// ``` /// /// Failing to parse: /// /// ``` /// let nope = "j".parse::(); /// /// assert!(nope.is_err()); /// ``` #[inline] #[stable(feature = "rust1", since = "1.0.0")] pub fn parse(&self) -> Result { StrExt::parse(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() } }} #[lang = "str"] #[cfg(not(test))] #[cfg(not(stage0))] impl str { str_core_methods!(); } #[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<'a> Default for &'a str { /// Creates an empty str fn default() -> &'a str { "" } } /// 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, IsNotEmpty>, } #[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 IsNotEmpty; impl<'a, 'b> FnOnce<(&'a &'b str, )> for IsNotEmpty { type Output = bool; #[inline] extern "rust-call" fn call_once(mut self, arg: (&&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: (&&str, )) -> bool { !arg.0.is_empty() } } #[stable(feature = "split_whitespace", since = "1.1.0")] impl<'a> Iterator for SplitWhitespace<'a> { type Item = &'a str; fn next(&mut self) -> Option<&'a str> { self.inner.next() } } #[stable(feature = "split_whitespace", since = "1.1.0")] impl<'a> DoubleEndedIterator for SplitWhitespace<'a> { fn next_back(&mut self) -> Option<&'a str> { self.inner.next_back() } } #[stable(feature = "fused", since = "1.26.0")] impl<'a> FusedIterator for SplitWhitespace<'a> {} /// 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, } // FIXME: remove (inline) this method // when updating to a bootstrap compiler that has the new lang items. // For grepping purpose: #[cfg(stage0)] impl<'a> EncodeUtf16<'a> { #[unstable(feature = "core_str_ext", issue = "32110")] #[doc(hidden)] pub fn new(s: &'a str) -> Self { EncodeUtf16 { chars: s.chars(), extra: 0 } } } #[stable(feature = "collection_debug", since = "1.17.0")] impl<'a> fmt::Debug for EncodeUtf16<'a> { 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 { 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) { 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<'a> FusedIterator for EncodeUtf16<'a> {}