gnzlbg
513 lines
15 KiB
Rust
513 lines
15 KiB
Rust
use std::borrow::Borrow;
|
||
use std::cmp;
|
||
use std::fmt;
|
||
use std::hash::{Hash, Hasher};
|
||
use std::ptr;
|
||
use std::ops::{Deref, DerefMut};
|
||
use std::str;
|
||
use std::str::Utf8Error;
|
||
use std::slice;
|
||
|
||
use array::{Array, ArrayExt};
|
||
use array::Index;
|
||
use CapacityError;
|
||
use char::encode_utf8;
|
||
|
||
#[cfg(feature="serde-1")]
|
||
use serde::{Serialize, Deserialize, Serializer, Deserializer};
|
||
|
||
/// A string with a fixed capacity.
|
||
///
|
||
/// The `ArrayString` is a string backed by a fixed size array. It keeps track
|
||
/// of its length.
|
||
///
|
||
/// The string is a contiguous value that you can store directly on the stack
|
||
/// if needed.
|
||
#[derive(Copy)]
|
||
pub struct ArrayString<A: Array<Item=u8>> {
|
||
xs: A,
|
||
len: A::Index,
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> Default for ArrayString<A> {
|
||
/// Return an empty `ArrayString`
|
||
fn default() -> ArrayString<A> {
|
||
ArrayString::new()
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> ArrayString<A> {
|
||
/// Create a new empty `ArrayString`.
|
||
///
|
||
/// Capacity is inferred from the type parameter.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 16]>::new();
|
||
/// string.push_str("foo");
|
||
/// assert_eq!(&string[..], "foo");
|
||
/// assert_eq!(string.capacity(), 16);
|
||
/// ```
|
||
pub fn new() -> ArrayString<A> {
|
||
unsafe {
|
||
ArrayString {
|
||
xs: ::new_array(),
|
||
len: Index::from(0),
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Create a new `ArrayString` from a `str`.
|
||
///
|
||
/// Capacity is inferred from the type parameter.
|
||
///
|
||
/// **Errors** if the backing array is not large enough to fit the string.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 3]>::from("foo").unwrap();
|
||
/// assert_eq!(&string[..], "foo");
|
||
/// assert_eq!(string.len(), 3);
|
||
/// assert_eq!(string.capacity(), 3);
|
||
/// ```
|
||
pub fn from(s: &str) -> Result<Self, CapacityError<&str>> {
|
||
let mut arraystr = Self::new();
|
||
arraystr.try_push_str(s)?;
|
||
Ok(arraystr)
|
||
}
|
||
|
||
/// Create a new `ArrayString` from a byte string literal.
|
||
///
|
||
/// **Errors** if the byte string literal is not valid UTF-8.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let string = ArrayString::from_byte_string(b"hello world").unwrap();
|
||
/// ```
|
||
pub fn from_byte_string(b: &A) -> Result<Self, Utf8Error> {
|
||
let mut arraystr = Self::new();
|
||
let s = try!(str::from_utf8(b.as_slice()));
|
||
let _result = arraystr.try_push_str(s);
|
||
debug_assert!(_result.is_ok());
|
||
Ok(arraystr)
|
||
}
|
||
|
||
/// Return the capacity of the `ArrayString`.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let string = ArrayString::<[_; 3]>::new();
|
||
/// assert_eq!(string.capacity(), 3);
|
||
/// ```
|
||
#[inline]
|
||
pub fn capacity(&self) -> usize { A::capacity() }
|
||
|
||
/// Return if the `ArrayString` is completely filled.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 1]>::new();
|
||
/// assert!(!string.is_full());
|
||
/// string.push_str("A");
|
||
/// assert!(string.is_full());
|
||
/// ```
|
||
pub fn is_full(&self) -> bool { self.len() == self.capacity() }
|
||
|
||
/// Adds the given char to the end of the string.
|
||
///
|
||
/// ***Panics*** if the backing array is not large enough to fit the additional char.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 2]>::new();
|
||
///
|
||
/// string.push('a');
|
||
/// string.push('b');
|
||
///
|
||
/// assert_eq!(&string[..], "ab");
|
||
/// ```
|
||
pub fn push(&mut self, c: char) {
|
||
self.try_push(c).unwrap();
|
||
}
|
||
|
||
/// Adds the given char to the end of the string.
|
||
///
|
||
/// Returns `Ok` if the push succeeds.
|
||
///
|
||
/// **Errors** if the backing array is not large enough to fit the additional char.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 2]>::new();
|
||
///
|
||
/// string.try_push('a').unwrap();
|
||
/// string.try_push('b').unwrap();
|
||
/// let overflow = string.try_push('c');
|
||
///
|
||
/// assert_eq!(&string[..], "ab");
|
||
/// assert_eq!(overflow.unwrap_err().element(), 'c');
|
||
/// ```
|
||
pub fn try_push(&mut self, c: char) -> Result<(), CapacityError<char>> {
|
||
let len = self.len();
|
||
unsafe {
|
||
match encode_utf8(c, &mut self.raw_mut_bytes()[len..]) {
|
||
Ok(n) => {
|
||
self.set_len(len + n);
|
||
Ok(())
|
||
}
|
||
Err(_) => Err(CapacityError::new(c)),
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Adds the given string slice to the end of the string.
|
||
///
|
||
/// ***Panics*** if the backing array is not large enough to fit the string.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 2]>::new();
|
||
///
|
||
/// string.push_str("a");
|
||
/// string.push_str("d");
|
||
///
|
||
/// assert_eq!(&string[..], "ad");
|
||
/// ```
|
||
pub fn push_str(&mut self, s: &str) {
|
||
self.try_push_str(s).unwrap()
|
||
}
|
||
|
||
/// Adds the given string slice to the end of the string.
|
||
///
|
||
/// Returns `Ok` if the push succeeds.
|
||
///
|
||
/// **Errors** if the backing array is not large enough to fit the string.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 2]>::new();
|
||
///
|
||
/// string.try_push_str("a").unwrap();
|
||
/// let overflow1 = string.try_push_str("bc");
|
||
/// string.try_push_str("d").unwrap();
|
||
/// let overflow2 = string.try_push_str("ef");
|
||
///
|
||
/// assert_eq!(&string[..], "ad");
|
||
/// assert_eq!(overflow1.unwrap_err().element(), "bc");
|
||
/// assert_eq!(overflow2.unwrap_err().element(), "ef");
|
||
/// ```
|
||
pub fn try_push_str<'a>(&mut self, s: &'a str) -> Result<(), CapacityError<&'a str>> {
|
||
if s.len() > self.capacity() - self.len() {
|
||
return Err(CapacityError::new(s));
|
||
}
|
||
unsafe {
|
||
let dst = self.xs.as_mut_ptr().offset(self.len() as isize);
|
||
let src = s.as_ptr();
|
||
ptr::copy_nonoverlapping(src, dst, s.len());
|
||
let newl = self.len() + s.len();
|
||
self.set_len(newl);
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
/// Removes the last character from the string and returns it.
|
||
///
|
||
/// Returns `None` if this `ArrayString` is empty.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut s = ArrayString::<[_; 3]>::from("foo").unwrap();
|
||
///
|
||
/// assert_eq!(s.pop(), Some('o'));
|
||
/// assert_eq!(s.pop(), Some('o'));
|
||
/// assert_eq!(s.pop(), Some('f'));
|
||
///
|
||
/// assert_eq!(s.pop(), None);
|
||
/// ```
|
||
#[inline]
|
||
pub fn pop(&mut self) -> Option<char> {
|
||
let ch = match self.chars().rev().next() {
|
||
Some(ch) => ch,
|
||
None => return None,
|
||
};
|
||
let new_len = self.len() - ch.len_utf8();
|
||
unsafe {
|
||
self.set_len(new_len);
|
||
}
|
||
Some(ch)
|
||
}
|
||
|
||
/// Shortens this `ArrayString` to the specified length.
|
||
///
|
||
/// If `new_len` is greater than the string’s current length, this has no
|
||
/// effect.
|
||
///
|
||
/// ***Panics*** if `new_len` does not lie on a `char` boundary.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut string = ArrayString::<[_; 6]>::from("foobar").unwrap();
|
||
/// string.truncate(3);
|
||
/// assert_eq!(&string[..], "foo");
|
||
/// string.truncate(4);
|
||
/// assert_eq!(&string[..], "foo");
|
||
/// ```
|
||
#[inline]
|
||
pub fn truncate(&mut self, new_len: usize) {
|
||
if new_len <= self.len() {
|
||
assert!(self.is_char_boundary(new_len));
|
||
unsafe {
|
||
// In libstd truncate is called on the underlying vector,
|
||
// which in turns drops each element.
|
||
// As we know we don't have to worry about Drop,
|
||
// we can just set the length (a la clear.)
|
||
self.set_len(new_len);
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Removes a `char` from this `ArrayString` at a byte position and returns it.
|
||
///
|
||
/// This is an `O(n)` operation, as it requires copying every element in the
|
||
/// array.
|
||
///
|
||
/// ***Panics*** if `idx` is larger than or equal to the `ArrayString`’s length,
|
||
/// or if it does not lie on a `char` boundary.
|
||
///
|
||
/// ```
|
||
/// use arrayvec::ArrayString;
|
||
///
|
||
/// let mut s = ArrayString::<[_; 3]>::from("foo").unwrap();
|
||
///
|
||
/// assert_eq!(s.remove(0), 'f');
|
||
/// assert_eq!(s.remove(1), 'o');
|
||
/// assert_eq!(s.remove(0), 'o');
|
||
/// ```
|
||
#[inline]
|
||
pub fn remove(&mut self, idx: usize) -> char {
|
||
let ch = match self[idx..].chars().next() {
|
||
Some(ch) => ch,
|
||
None => panic!("cannot remove a char from the end of a string"),
|
||
};
|
||
|
||
let next = idx + ch.len_utf8();
|
||
let len = self.len();
|
||
unsafe {
|
||
ptr::copy(self.xs.as_ptr().offset(next as isize),
|
||
self.xs.as_mut_ptr().offset(idx as isize),
|
||
len - next);
|
||
self.set_len(len - (next - idx));
|
||
}
|
||
ch
|
||
}
|
||
|
||
/// Make the string empty.
|
||
pub fn clear(&mut self) {
|
||
unsafe {
|
||
self.set_len(0);
|
||
}
|
||
}
|
||
|
||
/// Set the strings’s length.
|
||
///
|
||
/// This function is `unsafe` because it changes the notion of the
|
||
/// number of “valid” bytes in the string. Use with care.
|
||
///
|
||
/// This method uses *debug assertions* to check the validity of `length`
|
||
/// and may use other debug assertions.
|
||
#[inline]
|
||
pub unsafe fn set_len(&mut self, length: usize) {
|
||
debug_assert!(length <= self.capacity());
|
||
self.len = Index::from(length);
|
||
}
|
||
|
||
/// Return a string slice of the whole `ArrayString`.
|
||
pub fn as_str(&self) -> &str {
|
||
self
|
||
}
|
||
|
||
/// Return a mutable slice of the whole string’s buffer
|
||
unsafe fn raw_mut_bytes(&mut self) -> &mut [u8] {
|
||
slice::from_raw_parts_mut(self.xs.as_mut_ptr(), self.capacity())
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> Deref for ArrayString<A> {
|
||
type Target = str;
|
||
#[inline]
|
||
fn deref(&self) -> &str {
|
||
unsafe {
|
||
let sl = slice::from_raw_parts(self.xs.as_ptr(), self.len.to_usize());
|
||
str::from_utf8_unchecked(sl)
|
||
}
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> DerefMut for ArrayString<A> {
|
||
#[inline]
|
||
fn deref_mut(&mut self) -> &mut str {
|
||
unsafe {
|
||
let sl = slice::from_raw_parts_mut(self.xs.as_mut_ptr(), self.len.to_usize());
|
||
str::from_utf8_unchecked_mut(sl)
|
||
}
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> PartialEq for ArrayString<A> {
|
||
fn eq(&self, rhs: &Self) -> bool {
|
||
**self == **rhs
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> PartialEq<str> for ArrayString<A> {
|
||
fn eq(&self, rhs: &str) -> bool {
|
||
&**self == rhs
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> PartialEq<ArrayString<A>> for str {
|
||
fn eq(&self, rhs: &ArrayString<A>) -> bool {
|
||
self == &**rhs
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> Eq for ArrayString<A> { }
|
||
|
||
impl<A: Array<Item=u8>> Hash for ArrayString<A> {
|
||
fn hash<H: Hasher>(&self, h: &mut H) {
|
||
(**self).hash(h)
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> Borrow<str> for ArrayString<A> {
|
||
fn borrow(&self) -> &str { self }
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> AsRef<str> for ArrayString<A> {
|
||
fn as_ref(&self) -> &str { self }
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> fmt::Debug for ArrayString<A> {
|
||
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) }
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> fmt::Display for ArrayString<A> {
|
||
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { (**self).fmt(f) }
|
||
}
|
||
|
||
/// `Write` appends written data to the end of the string.
|
||
impl<A: Array<Item=u8>> fmt::Write for ArrayString<A> {
|
||
fn write_char(&mut self, c: char) -> fmt::Result {
|
||
self.try_push(c).map_err(|_| fmt::Error)
|
||
}
|
||
|
||
fn write_str(&mut self, s: &str) -> fmt::Result {
|
||
self.try_push_str(s).map_err(|_| fmt::Error)
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8> + Copy> Clone for ArrayString<A> {
|
||
fn clone(&self) -> ArrayString<A> {
|
||
*self
|
||
}
|
||
fn clone_from(&mut self, rhs: &Self) {
|
||
// guaranteed to fit due to types matching.
|
||
self.clear();
|
||
self.try_push_str(rhs).ok();
|
||
}
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> PartialOrd for ArrayString<A> {
|
||
fn partial_cmp(&self, rhs: &Self) -> Option<cmp::Ordering> {
|
||
(**self).partial_cmp(&**rhs)
|
||
}
|
||
fn lt(&self, rhs: &Self) -> bool { **self < **rhs }
|
||
fn le(&self, rhs: &Self) -> bool { **self <= **rhs }
|
||
fn gt(&self, rhs: &Self) -> bool { **self > **rhs }
|
||
fn ge(&self, rhs: &Self) -> bool { **self >= **rhs }
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> PartialOrd<str> for ArrayString<A> {
|
||
fn partial_cmp(&self, rhs: &str) -> Option<cmp::Ordering> {
|
||
(**self).partial_cmp(rhs)
|
||
}
|
||
fn lt(&self, rhs: &str) -> bool { &**self < rhs }
|
||
fn le(&self, rhs: &str) -> bool { &**self <= rhs }
|
||
fn gt(&self, rhs: &str) -> bool { &**self > rhs }
|
||
fn ge(&self, rhs: &str) -> bool { &**self >= rhs }
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> PartialOrd<ArrayString<A>> for str {
|
||
fn partial_cmp(&self, rhs: &ArrayString<A>) -> Option<cmp::Ordering> {
|
||
self.partial_cmp(&**rhs)
|
||
}
|
||
fn lt(&self, rhs: &ArrayString<A>) -> bool { self < &**rhs }
|
||
fn le(&self, rhs: &ArrayString<A>) -> bool { self <= &**rhs }
|
||
fn gt(&self, rhs: &ArrayString<A>) -> bool { self > &**rhs }
|
||
fn ge(&self, rhs: &ArrayString<A>) -> bool { self >= &**rhs }
|
||
}
|
||
|
||
impl<A: Array<Item=u8>> Ord for ArrayString<A> {
|
||
fn cmp(&self, rhs: &Self) -> cmp::Ordering {
|
||
(**self).cmp(&**rhs)
|
||
}
|
||
}
|
||
|
||
#[cfg(feature="serde-1")]
|
||
/// Requires crate feature `"serde-1"`
|
||
impl<A: Array<Item=u8>> Serialize for ArrayString<A> {
|
||
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
|
||
where S: Serializer
|
||
{
|
||
serializer.serialize_str(&*self)
|
||
}
|
||
}
|
||
|
||
#[cfg(feature="serde-1")]
|
||
/// Requires crate feature `"serde-1"`
|
||
impl<'de, A: Array<Item=u8>> Deserialize<'de> for ArrayString<A> {
|
||
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
|
||
where D: Deserializer<'de>
|
||
{
|
||
use serde::de::{self, Visitor};
|
||
use std::marker::PhantomData;
|
||
|
||
struct ArrayStringVisitor<A: Array<Item=u8>>(PhantomData<A>);
|
||
|
||
impl<'de, A: Array<Item=u8>> Visitor<'de> for ArrayStringVisitor<A> {
|
||
type Value = ArrayString<A>;
|
||
|
||
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
|
||
write!(formatter, "a string no more than {} bytes long", A::capacity())
|
||
}
|
||
|
||
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
|
||
where E: de::Error,
|
||
{
|
||
ArrayString::from(v).map_err(|_| E::invalid_length(v.len(), &self))
|
||
}
|
||
|
||
fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
|
||
where E: de::Error,
|
||
{
|
||
let s = try!(str::from_utf8(v).map_err(|_| E::invalid_value(de::Unexpected::Bytes(v), &self)));
|
||
|
||
ArrayString::from(s).map_err(|_| E::invalid_length(s.len(), &self))
|
||
}
|
||
}
|
||
|
||
deserializer.deserialize_str(ArrayStringVisitor::<A>(PhantomData))
|
||
}
|
||
}
|