| // 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 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, 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 clone::Clone; |
| use convert::AsRef; |
| use default::Default; |
| use fmt; |
| use iter::ExactSizeIterator; |
| use iter::{Map, Cloned, Iterator, DoubleEndedIterator}; |
| use marker::Sized; |
| use mem; |
| use ops::{Fn, FnMut, FnOnce}; |
| use option::Option::{self, None, Some}; |
| use result::Result::{self, Ok, Err}; |
| use slice::{self, SliceExt}; |
| |
| pub mod pattern; |
| |
| /// 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 |
| #[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. |
| /// |
| /// # Examples |
| /// |
| /// Basic usage with [`i32`][ithirtytwo], a type that implements `FromStr`: |
| /// |
| /// [ithirtytwo]: ../../std/primitive.i32.html |
| /// |
| /// ``` |
| /// use std::str::FromStr; |
| /// |
| /// let s = "5"; |
| /// let x = i32::from_str(s).unwrap(); |
| /// |
| /// assert_eq!(5, x); |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| fn from_str(s: &str) -> Result<Self, Self::Err>; |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl FromStr for bool { |
| type Err = ParseBoolError; |
| |
| /// Parse a `bool` from a string. |
| /// |
| /// Yields a `Result<bool, ParseBoolError>`, because `s` may or may not |
| /// actually be parseable. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// use std::str::FromStr; |
| /// |
| /// assert_eq!(FromStr::from_str("true"), Ok(true)); |
| /// assert_eq!(FromStr::from_str("false"), Ok(false)); |
| /// assert!(<bool as FromStr>::from_str("not even a boolean").is_err()); |
| /// ``` |
| /// |
| /// Note, in many cases, the `.parse()` method on `str` is more proper. |
| /// |
| /// ``` |
| /// assert_eq!("true".parse(), Ok(true)); |
| /// assert_eq!("false".parse(), Ok(false)); |
| /// assert!("not even a boolean".parse::<bool>().is_err()); |
| /// ``` |
| #[inline] |
| fn from_str(s: &str) -> Result<bool, ParseBoolError> { |
| match s { |
| "true" => Ok(true), |
| "false" => Ok(false), |
| _ => Err(ParseBoolError { _priv: () }), |
| } |
| } |
| } |
| |
| /// An error returned when parsing a `bool` from a string fails. |
| #[derive(Debug, Clone, PartialEq)] |
| #[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. |
| /// |
| /// As such, the `from_utf8` family of functions and methods for both `String`s |
| /// and `&str`s make use of this error, for example. |
| #[derive(Copy, Eq, PartialEq, Clone, Debug)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Utf8Error { |
| valid_up_to: usize, |
| } |
| |
| 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 `Some(_)`. |
| /// |
| /// # 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 } |
| } |
| |
| /// Converts a slice of bytes to a string slice. |
| /// |
| /// A string slice (`&str`) is made of bytes (`u8`), and a byte slice (`&[u8]`) |
| /// 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. |
| /// |
| /// 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]` of |
| /// it, this function is one way to have a stack-allocated string. There is |
| /// an example of this in the examples section below. |
| /// |
| /// # 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) }) |
| } |
| |
| /// 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 str. |
| /// |
| /// # 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 { |
| mem::transmute::<&mut [u8], &mut str>(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. |
| /// |
| /// # 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(always)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub unsafe fn from_utf8_unchecked(v: &[u8]) -> &str { |
| mem::transmute(v) |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl fmt::Display for Utf8Error { |
| fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { |
| write!(f, "invalid utf-8: invalid byte near index {}", self.valid_up_to) |
| } |
| } |
| |
| /* |
| Section: Iterators |
| */ |
| |
| /// Iterator for the char (representing *Unicode Scalar Values*) of a string |
| /// |
| /// Created with the method [`chars()`]. |
| /// |
| /// [`chars()`]: ../../std/primitive.str.html#method.chars |
| #[derive(Clone, Debug)] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| pub struct Chars<'a> { |
| iter: slice::Iter<'a, u8> |
| } |
| |
| /// Return 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 } |
| |
| /// Return the value of `ch` updated with continuation byte `byte`. |
| #[inline] |
| fn utf8_acc_cont_byte(ch: u32, byte: u8) -> u32 { (ch << 6) | (byte & CONT_MASK) as u32 } |
| |
| /// Checks whether the byte is a UTF-8 continuation byte (i.e. starts with the |
| /// bits `10`). |
| #[inline] |
| fn utf8_is_cont_byte(byte: u8) -> bool { (byte & !CONT_MASK) == TAG_CONT_U8 } |
| |
| #[inline] |
| fn unwrap_or_0(opt: Option<&u8>) -> u8 { |
| match opt { |
| Some(&byte) => byte, |
| None => 0, |
| } |
| } |
| |
| /// Reads the next code point out of a byte iterator (assuming a |
| /// UTF-8-like encoding). |
| #[unstable(feature = "str_internals", issue = "0")] |
| #[inline] |
| pub fn next_code_point<'a, I: Iterator<Item = &'a u8>>(bytes: &mut I) -> Option<u32> { |
| // Decode UTF-8 |
| let x = match bytes.next() { |
| None => return None, |
| Some(&next_byte) if next_byte < 128 => return Some(next_byte as u32), |
| Some(&next_byte) => next_byte, |
| }; |
| |
| // 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: DoubleEndedIterator<Item = &'a u8>>(bytes: &mut I) -> Option<u32> { |
| // 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<char> { |
| next_code_point(&mut self.iter).map(|ch| { |
| // str invariant says `ch` is a valid Unicode Scalar Value |
| unsafe { |
| char::from_u32_unchecked(ch) |
| } |
| }) |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| let len = self.iter.len(); |
| // `(len + 3)` can't overflow, because we know that the `slice::Iter` |
| // belongs to a slice in memory which has a maximum length of |
| // `isize::MAX` (that's well below `usize::MAX`). |
| ((len + 3) / 4, Some(len)) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> DoubleEndedIterator for Chars<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<char> { |
| next_code_point_reverse(&mut self.iter).map(|ch| { |
| // str invariant says `ch` is a valid Unicode Scalar Value |
| unsafe { |
| char::from_u32_unchecked(ch) |
| } |
| }) |
| } |
| } |
| |
| 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. |
| #[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()) } |
| } |
| } |
| |
| /// Iterator for a string's characters and their byte offsets. |
| #[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 size_hint(&self) -> (usize, Option<usize>) { |
| self.iter.size_hint() |
| } |
| } |
| |
| #[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)) |
| } |
| } |
| } |
| } |
| |
| 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() |
| } |
| } |
| |
| /// External iterator for a string's bytes. |
| /// Use with the `std::iter` module. |
| /// |
| /// Created with the method [`bytes()`]. |
| /// |
| /// [`bytes()`]: ../../std/primitive.str.html#method.bytes |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[derive(Clone, Debug)] |
| pub struct Bytes<'a>(Cloned<slice::Iter<'a, u8>>); |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> Iterator for Bytes<'a> { |
| type Item = u8; |
| |
| #[inline] |
| fn next(&mut self) -> Option<u8> { |
| self.0.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.0.size_hint() |
| } |
| |
| #[inline] |
| fn count(self) -> usize { |
| self.0.count() |
| } |
| |
| #[inline] |
| fn last(self) -> Option<Self::Item> { |
| self.0.last() |
| } |
| |
| #[inline] |
| fn nth(&mut self, n: usize) -> Option<Self::Item> { |
| self.0.nth(n) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> DoubleEndedIterator for Bytes<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<u8> { |
| self.0.next_back() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> ExactSizeIterator for Bytes<'a> { |
| #[inline] |
| fn len(&self) -> usize { |
| self.0.len() |
| } |
| } |
| |
| /// 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 delgation - 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 { |
| $reverse_iterator(self.0.clone()) |
| } |
| } |
| |
| generate_pattern_iterators!($($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; |
| } |
| |
| /// Created with the method [`lines()`]. |
| /// |
| /// [`lines()`]: ../../std/primitive.str.html#method.lines |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[derive(Clone, Debug)] |
| pub struct Lines<'a>(Map<SplitTerminator<'a, char>, LinesAnyMap>); |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> Iterator for Lines<'a> { |
| type Item = &'a str; |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.0.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.0.size_hint() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl<'a> DoubleEndedIterator for Lines<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> { |
| self.0.next_back() |
| } |
| } |
| |
| /// Created with the method [`lines_any()`]. |
| /// |
| /// [`lines_any()`]: ../../std/primitive.str.html#method.lines_any |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[rustc_deprecated(since = "1.4.0", reason = "use lines()/Lines instead now")] |
| #[derive(Clone, Debug)] |
| #[allow(deprecated)] |
| pub struct LinesAny<'a>(Lines<'a>); |
| |
| /// A nameable, cloneable fn type |
| #[derive(Clone)] |
| struct LinesAnyMap; |
| |
| impl<'a> Fn<(&'a str,)> for LinesAnyMap { |
| #[inline] |
| extern "rust-call" fn call(&self, (line,): (&'a str,)) -> &'a str { |
| let l = line.len(); |
| if l > 0 && line.as_bytes()[l - 1] == b'\r' { &line[0 .. l - 1] } |
| else { line } |
| } |
| } |
| |
| impl<'a> FnMut<(&'a str,)> for LinesAnyMap { |
| #[inline] |
| extern "rust-call" fn call_mut(&mut self, (line,): (&'a str,)) -> &'a str { |
| Fn::call(&*self, (line,)) |
| } |
| } |
| |
| impl<'a> FnOnce<(&'a str,)> for LinesAnyMap { |
| type Output = &'a str; |
| |
| #[inline] |
| extern "rust-call" fn call_once(self, (line,): (&'a str,)) -> &'a str { |
| Fn::call(&self, (line,)) |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| impl<'a> Iterator for LinesAny<'a> { |
| type Item = &'a str; |
| |
| #[inline] |
| fn next(&mut self) -> Option<&'a str> { |
| self.0.next() |
| } |
| |
| #[inline] |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.0.size_hint() |
| } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow(deprecated)] |
| impl<'a> DoubleEndedIterator for LinesAny<'a> { |
| #[inline] |
| fn next_back(&mut self) -> Option<&'a str> { |
| self.0.next_back() |
| } |
| } |
| |
| /* |
| Section: Comparing strings |
| */ |
| |
| /// Bytewise slice equality |
| /// NOTE: This function is (ab)used in rustc::middle::trans::_match |
| /// to compare &[u8] byte slices that are not necessarily valid UTF-8. |
| #[lang = "str_eq"] |
| #[inline] |
| fn eq_slice(a: &str, b: &str) -> bool { |
| a.as_bytes() == b.as_bytes() |
| } |
| |
| /* |
| Section: UTF-8 validation |
| */ |
| |
| // use truncation to fit u64 into usize |
| const NONASCII_MASK: usize = 0x80808080_80808080u64 as usize; |
| |
| /// Return `true` if any byte in the word `x` is nonascii (>= 128). |
| #[inline] |
| fn contains_nonascii(x: usize) -> bool { |
| (x & NONASCII_MASK) != 0 |
| } |
| |
| /// Walk 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(always)] |
| fn run_utf8_validation(v: &[u8]) -> Result<(), Utf8Error> { |
| let mut offset = 0; |
| let len = v.len(); |
| while offset < len { |
| let old_offset = offset; |
| macro_rules! err { () => {{ |
| return Err(Utf8Error { |
| valid_up_to: old_offset |
| }) |
| }}} |
| |
| macro_rules! next { () => {{ |
| offset += 1; |
| // we needed data, but there was none: error! |
| if offset >= len { |
| err!() |
| } |
| v[offset] |
| }}} |
| |
| let first = v[offset]; |
| if first >= 128 { |
| let w = UTF8_CHAR_WIDTH[first as usize]; |
| let second = next!(); |
| // 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 second & !CONT_MASK != TAG_CONT_U8 {err!()}, |
| 3 => { |
| match (first, second, next!() & !CONT_MASK) { |
| (0xE0 , 0xA0 ... 0xBF, TAG_CONT_U8) | |
| (0xE1 ... 0xEC, 0x80 ... 0xBF, TAG_CONT_U8) | |
| (0xED , 0x80 ... 0x9F, TAG_CONT_U8) | |
| (0xEE ... 0xEF, 0x80 ... 0xBF, TAG_CONT_U8) => {} |
| _ => err!() |
| } |
| } |
| 4 => { |
| match (first, second, next!() & !CONT_MASK, next!() & !CONT_MASK) { |
| (0xF0 , 0x90 ... 0xBF, TAG_CONT_U8, TAG_CONT_U8) | |
| (0xF1 ... 0xF3, 0x80 ... 0xBF, TAG_CONT_U8, TAG_CONT_U8) | |
| (0xF4 , 0x80 ... 0x8F, TAG_CONT_U8, TAG_CONT_U8) => {} |
| _ => err!() |
| } |
| } |
| _ => err!() |
| } |
| offset += 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 usize_bytes = mem::size_of::<usize>(); |
| let bytes_per_iteration = 2 * usize_bytes; |
| let ptr = v.as_ptr(); |
| let align = (ptr as usize + offset) & (usize_bytes - 1); |
| if align == 0 { |
| if len >= bytes_per_iteration { |
| while offset <= len - bytes_per_iteration { |
| unsafe { |
| let u = *(ptr.offset(offset as isize) as *const usize); |
| let v = *(ptr.offset((offset + usize_bytes) as isize) as *const usize); |
| |
| // break if there is a nonascii byte |
| let zu = contains_nonascii(u); |
| let zv = contains_nonascii(v); |
| if zu || zv { |
| break; |
| } |
| } |
| offset += bytes_per_iteration; |
| } |
| } |
| // step from the point where the wordwise loop stopped |
| while offset < len && v[offset] < 128 { |
| offset += 1; |
| } |
| } else { |
| offset += 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 |
| ]; |
| |
| /// 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::{Ord, Ordering, PartialEq, PartialOrd, Eq}; |
| use option::Option; |
| use option::Option::Some; |
| use ops; |
| use str::{StrExt, eq_slice}; |
| |
| #[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 { |
| eq_slice(self, other) |
| } |
| #[inline] |
| fn ne(&self, other: &str) -> bool { !(*self).eq(other) } |
| } |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl Eq for str {} |
| |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl PartialOrd for str { |
| #[inline] |
| fn partial_cmp(&self, other: &str) -> Option<Ordering> { |
| Some(self.cmp(other)) |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[begin .. end]`. |
| /// |
| /// Returns a slice of the given string from the byte range |
| /// [`begin`..`end`). |
| /// |
| /// This operation is `O(1)`. |
| /// |
| /// # Panics |
| /// |
| /// Panics if `begin` or `end` does not point to the starting |
| /// byte offset of a character (as defined by `is_char_boundary`). |
| /// Requires that `begin <= end` and `end <= len` where `len` is the |
| /// length of the string. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// let s = "Löwe 老虎 Léopard"; |
| /// assert_eq!(&s[0 .. 1], "L"); |
| /// |
| /// assert_eq!(&s[1 .. 9], "öwe 老"); |
| /// |
| /// // these will panic: |
| /// // byte 2 lies within `ö`: |
| /// // &s[2 ..3]; |
| /// |
| /// // byte 8 lies within `老` |
| /// // &s[1 .. 8]; |
| /// |
| /// // byte 100 is outside the string |
| /// // &s[3 .. 100]; |
| /// ``` |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::Range<usize>> for str { |
| type Output = str; |
| #[inline] |
| fn index(&self, index: ops::Range<usize>) -> &str { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if index.start <= index.end && |
| self.is_char_boundary(index.start) && |
| self.is_char_boundary(index.end) { |
| unsafe { self.slice_unchecked(index.start, index.end) } |
| } else { |
| super::slice_error_fail(self, index.start, index.end) |
| } |
| } |
| } |
| |
| /// 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 = "1.2.0")] |
| impl ops::IndexMut<ops::Range<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::Range<usize>) -> &mut str { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if index.start <= index.end && |
| self.is_char_boundary(index.start) && |
| self.is_char_boundary(index.end) { |
| unsafe { self.slice_mut_unchecked(index.start, index.end) } |
| } else { |
| super::slice_error_fail(self, index.start, index.end) |
| } |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[.. end]`. |
| /// |
| /// Returns a slice of the string from the beginning to byte offset |
| /// `end`. |
| /// |
| /// Equivalent to `&self[0 .. end]`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::RangeTo<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeTo<usize>) -> &str { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if self.is_char_boundary(index.end) { |
| unsafe { self.slice_unchecked(0, index.end) } |
| } else { |
| super::slice_error_fail(self, 0, index.end) |
| } |
| } |
| } |
| |
| /// 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 = "1.2.0")] |
| impl ops::IndexMut<ops::RangeTo<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut str { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if self.is_char_boundary(index.end) { |
| unsafe { self.slice_mut_unchecked(0, index.end) } |
| } else { |
| super::slice_error_fail(self, 0, index.end) |
| } |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[begin ..]`. |
| /// |
| /// Returns a slice of the string from byte offset `begin` |
| /// to the end of the string. |
| /// |
| /// Equivalent to `&self[begin .. len]`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::RangeFrom<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeFrom<usize>) -> &str { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if self.is_char_boundary(index.start) { |
| unsafe { self.slice_unchecked(index.start, self.len()) } |
| } else { |
| super::slice_error_fail(self, index.start, self.len()) |
| } |
| } |
| } |
| |
| /// 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 = "1.2.0")] |
| impl ops::IndexMut<ops::RangeFrom<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut str { |
| // is_char_boundary checks that the index is in [0, .len()] |
| if self.is_char_boundary(index.start) { |
| let len = self.len(); |
| unsafe { self.slice_mut_unchecked(index.start, len) } |
| } else { |
| super::slice_error_fail(self, index.start, self.len()) |
| } |
| } |
| } |
| |
| /// Implements substring slicing with syntax `&self[..]`. |
| /// |
| /// Returns a slice of the whole string. This operation can |
| /// never panic. |
| /// |
| /// Equivalent to `&self[0 .. len]`. |
| #[stable(feature = "rust1", since = "1.0.0")] |
| impl ops::Index<ops::RangeFull> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, _index: ops::RangeFull) -> &str { |
| self |
| } |
| } |
| |
| /// Implements mutable substring slicing with syntax `&mut self[..]`. |
| /// |
| /// Returns a mutable slice of the whole string. This operation can |
| /// never panic. |
| /// |
| /// Equivalent to `&mut self[0 .. len]`. |
| #[stable(feature = "derefmut_for_string", since = "1.2.0")] |
| impl ops::IndexMut<ops::RangeFull> for str { |
| #[inline] |
| fn index_mut(&mut self, _index: ops::RangeFull) -> &mut str { |
| self |
| } |
| } |
| |
| #[unstable(feature = "inclusive_range", |
| reason = "recently added, follows RFC", |
| issue = "28237")] |
| impl ops::Index<ops::RangeInclusive<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeInclusive<usize>) -> &str { |
| match index { |
| ops::RangeInclusive::Empty { .. } => "", |
| ops::RangeInclusive::NonEmpty { end, .. } if end == usize::max_value() => |
| panic!("attempted to index slice up to maximum usize"), |
| ops::RangeInclusive::NonEmpty { start, end } => |
| self.index(start .. end+1) |
| } |
| } |
| } |
| #[unstable(feature = "inclusive_range", |
| reason = "recently added, follows RFC", |
| issue = "28237")] |
| impl ops::Index<ops::RangeToInclusive<usize>> for str { |
| type Output = str; |
| |
| #[inline] |
| fn index(&self, index: ops::RangeToInclusive<usize>) -> &str { |
| self.index(0...index.end) |
| } |
| } |
| |
| #[unstable(feature = "inclusive_range", |
| reason = "recently added, follows RFC", |
| issue = "28237")] |
| impl ops::IndexMut<ops::RangeInclusive<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut str { |
| match index { |
| ops::RangeInclusive::Empty { .. } => &mut self[0..0], // `&mut ""` doesn't work |
| ops::RangeInclusive::NonEmpty { end, .. } if end == usize::max_value() => |
| panic!("attempted to index str up to maximum usize"), |
| ops::RangeInclusive::NonEmpty { start, end } => |
| self.index_mut(start .. end+1) |
| } |
| } |
| } |
| #[unstable(feature = "inclusive_range", |
| reason = "recently added, follows RFC", |
| issue = "28237")] |
| impl ops::IndexMut<ops::RangeToInclusive<usize>> for str { |
| #[inline] |
| fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut str { |
| self.index_mut(0...index.end) |
| } |
| } |
| } |
| |
| /// 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")] |
| pub trait StrExt { |
| // NB there are no docs here are they're all located on the StrExt trait in |
| // libcollections, 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 = "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 = "core", since = "1.6.0")] |
| fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize>; |
| #[stable(feature = "core", since = "1.6.0")] |
| fn rfind<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> |
| where P::Searcher: ReverseSearcher<'a>; |
| fn find_str<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize>; |
| #[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<T: FromStr>(&self) -> Result<T, T::Err>; |
| } |
| |
| // 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) = truncate_to_char_boundary(s, MAX_DISPLAY_LENGTH); |
| let ellipsis = if truncated { "[...]" } else { "" }; |
| |
| assert!(begin <= end, "begin <= end ({} <= {}) when slicing `{}`{}", |
| begin, end, s, ellipsis); |
| panic!("index {} and/or {} in `{}`{} do not lie on character boundary", |
| begin, end, s, 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: 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] |
| unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str { |
| let ptr = self.as_ptr().offset(begin as isize); |
| let len = end - begin; |
| from_utf8_unchecked(slice::from_raw_parts(ptr, len)) |
| } |
| |
| #[inline] |
| unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str { |
| let ptr = self.as_ptr().offset(begin as isize); |
| let len = end - begin; |
| mem::transmute(slice::from_raw_parts_mut(ptr as *mut u8, len)) |
| } |
| |
| #[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 { mem::transmute(self) } |
| } |
| |
| fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> { |
| pat.into_searcher(self).next_match().map(|(i, _)| i) |
| } |
| |
| fn rfind<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> |
| where P::Searcher: ReverseSearcher<'a> |
| { |
| pat.into_searcher(self).next_match_back().map(|(i, _)| i) |
| } |
| |
| fn find_str<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize> { |
| 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<T: FromStr>(&self) -> Result<T, T::Err> { FromStr::from_str(self) } |
| } |
| |
| #[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 { |
| fn default() -> &'a str { "" } |
| } |
