//! [`ArrayVec`](../tinyvec/struct.ArrayVec.html) backed strings
use crate::{bytearray::ByteArray, tinyvec::ArrayVec};
use core::{
convert::{TryFrom, TryInto},
fmt,
hash::{Hash, Hasher},
iter::{DoubleEndedIterator, FromIterator, FusedIterator},
ops::{
self, Add, AddAssign, Bound, Deref, DerefMut, Index, IndexMut,
RangeBounds,
},
ptr,
str::{self, Chars, FromStr, Utf8Error},
};
#[cfg(feature = "alloc")]
use alloc::{borrow::Cow, string::String};
/// A UTF-8 encoded, fixed-capacity string.
///
/// An `ArrayString` is similar to [`String`], but is backed by an
/// [`ArrayVec`] instead of a [`Vec`]. This means it has similar
/// characteristics to `ArrayVec`:
/// * An `ArrayString` has a fixed capacity (in bytes), the size of the backing
/// array.
/// * An `ArrayString` has a dynamic length; characters can be added and
/// removed. Attempting to add characters when the capacity has been reached
/// will cause a panic.
///
/// Like `String`, the contents of an `ArrayString` must be valid UTF-8 at all
/// times.
///
/// `ArrayString` is intended to replicate the API of `String` as much as
/// possible. Like `ArrayVec`, some methods cannot be implemented, like
/// `from_raw_parts` or `reserve`
///
/// # Examples
/// Creating `ArrayString`s with [`TryFrom`]:
/// ```
/// # use tinyvec_string::ArrayString;
/// use std::convert::TryFrom;
/// // explicitly specifying the backing array type with a turbofish
/// // note that `try_from` fails if the backing array is not large enough
/// // to contain the string contents
/// let s1 = ArrayString::<[u8; 13]>::try_from("Hello, world!").unwrap();
///
/// assert_eq!(s1, "Hello, world!");
///
/// // annotate the variable type to specify the backing array
/// let s2: ArrayString<[u8; 13]> = ArrayString::try_from("Hello, world!").unwrap();
///
/// assert_eq!(s1, s2);
///
/// // `collect` (which uses `FromIterator`) will panic if the backing array
/// // is not large enough
/// let s3: ArrayString<[u8; 12]> =
/// vec!["foo", "bar", "baz"].into_iter().collect();
///
/// assert_eq!(s3, "foobarbaz");
/// ```
///
/// Creating `ArrayString`s with the [`from`] convenience method:
/// ```
/// # use tinyvec_string::ArrayString;
/// // this panics on capacity overflow
/// let s = ArrayString::<[u8; 6]>::from("foobar");
/// ```
///
/// [`String`]: https://doc.rust-lang.org/std/string/struct.String.html
/// [`ArrayVec`]: ../tinyvec/struct.ArrayVec.html
/// [`Vec`]: https://doc.rust-lang.org/std/vec/struct.Vec.html
/// [`TryFrom`]: https://doc.rust-lang.org/std/convert/trait.TryFrom.html
/// [`from`]: #method.from
#[derive(Copy, Eq, PartialOrd, Ord)]
#[repr(transparent)]
pub struct ArrayString<A: ByteArray> {
vec: ArrayVec<A>,
}
impl<A: ByteArray> Default for ArrayString<A> {
fn default() -> Self {
ArrayString {
vec: ArrayVec::from_array_len(A::DEFAULT, 0),
}
}
}
impl<A: ByteArray> ArrayString<A> {
/// Creates a new empty `ArrayString`.
///
/// This creates a new [`ArrayVec`] with a backing array of zeroes.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// // create an `ArrayString` with 16 bytes of capacity
/// let s = ArrayString::<[u8; 16]>::new();
/// ```
///
/// [`ArrayVec`]: ../tinyvec/struct.ArrayVec.html
#[inline]
pub fn new() -> ArrayString<A> {
Self::default()
}
/// Creates a new `ArrayString` from another string type.
///
/// This can be used to create an `ArrayString` from any type with an
/// applicable [`TryFrom`] implementation:
/// * `&str`
/// * `&mut str`
/// * `char`
/// * `&char`
/// * `String`
/// * `&String`
/// * `Cow<str>`
///
/// [`TryFrom`]: https://doc.rust-lang.org/std/convert/trait.TryFrom.html
///
/// Because it relies on `TryFrom`, this method may panic (which is why it
/// is not a `From` implementation).
///
/// # Panics
/// Panics if the input string is larger than the backing array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 13]>::from("Hello, world!");
///
/// assert_eq!(s, "Hello, world!");
/// ```
///
/// This method panics when the string is too large:
/// ```should_panic
/// # use tinyvec_string::ArrayString;
/// // the following line will panic!
/// let s = ArrayString::<[u8; 10]>::from("This is quite a long string");
/// ```
pub fn from<S>(s: S) -> Self
where
S: fmt::Debug,
Self: TryFrom<S, Error = CapacityOverflowError<S>>,
{
s.try_into().expect("Failed to convert into ArrayString")
}
/// Converts a vector of bytes to an `ArrayString`.
///
/// `ArrayString` is backed by `ArrayVec`, so after ensuring valid UTF-8,
/// this function simply constructs an `ArrayString` containing the
/// provided `ArrayVec`.
///
/// The inverse of this method is [`into_bytes`].
///
/// # Errors
///
/// Returns `Err` if the slice is not UTF-8 with a description as to why the
/// provided bytes are not UTF-8. The vector you moved in is also included.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
/// // some bytes, in a vector
/// let ferris: ArrayVec<[u8; 7]> = array_vec![240, 159, 166, 128, 226, 153, 165];
///
/// // We know these bytes are valid UTF-8, so we'll use `unwrap()`.
/// let ferris = ArrayString::from_utf8(ferris).unwrap();
///
/// assert_eq!("🦀♥", ferris);
/// ```
///
/// Incorrect bytes:
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
///
/// // some invalid bytes, in a vector
/// let ferris: ArrayVec<[u8; 7]> = array_vec![0, 159, 166, 128, 226, 153, 165];
///
/// assert!(ArrayString::from_utf8(ferris).is_err());
/// ```
///
/// See the docs for [`FromUtf8Error`] for more details on what you can do
/// with this error.
///
/// [`into_bytes`]: struct.ArrayString.html#method.into_bytes
/// [`FromUtf8Error`]: struct.FromUtf8Error.html
#[inline]
pub fn from_utf8(
vec: ArrayVec<A>,
) -> Result<ArrayString<A>, FromUtf8Error<A>> {
match str::from_utf8(&vec) {
Ok(..) => Ok(ArrayString { vec }),
Err(error) => Err(FromUtf8Error { vec, error }),
}
}
/// Converts a vector of bytes to an `ArrayString` without checking that
/// the string contains valid UTF-8.
///
/// See the safe version, [`from_utf8`], for more details.
///
/// [`from_utf8`]: struct.ArrayString.html#method.from_utf8
///
/// # 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, it may cause
/// memory unsafety issues with future users of the `ArrayString`, as the
/// rest of this library and the standard library assumes that `str`s are
/// valid UTF-8.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
/// // some bytes, in a vector
/// let ferris: ArrayVec<[u8; 7]> = array_vec![240, 159, 166, 128, 226, 153, 165];
///
/// let ferris = unsafe {
/// // we know these bytes are valid UTF-8, so this is sound.
/// ArrayString::from_utf8_unchecked(ferris)
/// };
///
/// assert_eq!("🦀♥", ferris);
/// ```
#[inline]
pub unsafe fn from_utf8_unchecked(vec: ArrayVec<A>) -> ArrayString<A> {
ArrayString { vec }
}
/// Returns an `ArrayString`'s backing [`ArrayVec`].
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 5]>::from("hello");
/// let bytes = s.into_bytes();
///
/// assert_eq!(&[104, 101, 108, 108, 111][..], &bytes[..]);
/// ```
/// [`ArrayVec`]: ../tinyvec/struct.ArrayVec.html
#[inline]
pub fn into_bytes(self) -> ArrayVec<A> {
self.vec
}
/// Extracts a string slice containing the entire `ArrayString`.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 3]>::from("foo");
///
/// assert_eq!("foo", s.as_str());
/// ```
#[inline]
pub fn as_str(&self) -> &str {
&*self
}
/// Extracts a mutable string slice containing the entire `ArrayString`.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("foobar");
/// let s_mut_str = s.as_mut_str();
///
/// s_mut_str.make_ascii_uppercase();
///
/// assert_eq!("FOOBAR", s_mut_str);
/// ```
#[inline]
pub fn as_mut_str(&mut self) -> &mut str {
&mut *self
}
/// Returns a byte slice of this `ArrayString`'s contents.
///
/// The inverse of this method is [`from_utf8`].
///
/// [`from_utf8`]: #method.from_utf8
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 5]>::from("hello");
///
/// assert_eq!(&[104, 101, 108, 108, 111], s.as_bytes());
/// ```
#[inline]
pub fn as_bytes(&self) -> &[u8] {
&*self.vec
}
/// Returns a mutable reference to the contents of this `ArrayString`.
///
/// # 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, it may cause
/// memory unsafety issues with future users of the `ArrayString`, as the
/// rest of the standard library assumes that `ArrayString`s are valid
/// UTF-8.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 5]>::from("hello");
///
/// unsafe {
/// let vec = s.as_mut_vec();
/// assert_eq!(&[104, 101, 108, 108, 111][..], &vec[..]);
///
/// vec.reverse();
/// }
/// assert_eq!(s, "olleh");
/// ```
#[inline]
pub unsafe fn as_mut_vec(&mut self) -> &mut ArrayVec<A> {
&mut self.vec
}
/// Returns this `ArrayString`'s capacity, in bytes.
///
/// This always returns a constant, the size of the backing array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 16]>::new();
///
/// assert!(s.capacity() == 16);
/// ```
#[inline]
pub fn capacity(&self) -> usize {
self.vec.capacity()
}
/// Returns the length of this `ArrayString`, in bytes, not [`char`]s or
/// graphemes. In other words, it may not be what a human considers the
/// length of the string.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let plain_f = ArrayString::<[u8; 3]>::from("foo");
/// assert_eq!(plain_f.len(), 3);
///
/// let fancy_f = ArrayString::<[u8; 4]>::from("Æ’oo");
/// assert_eq!(fancy_f.len(), 4);
/// assert_eq!(fancy_f.chars().count(), 3);
///
/// let s = ArrayString::<[u8; 16]>::from("hello");
/// assert_eq!(s.len(), 5);
/// ```
#[inline]
pub fn len(&self) -> usize {
self.vec.len()
}
/// Returns `true` if this `ArrayString` has a length of zero, and `false`
/// otherwise.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 5]>::new();
/// assert!(s.is_empty());
///
/// s.push('a');
/// assert!(!s.is_empty());
/// ```
#[inline]
pub fn is_empty(&self) -> bool {
self.len() == 0
}
/// Appends a given string slice onto the end of this `ArrayString`.
///
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the
/// backing array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("foo");
///
/// s.push_str("bar");
///
/// assert_eq!("foobar", s);
/// ```
#[inline]
pub fn push_str(&mut self, string: &str) {
self.vec.extend_from_slice(string.as_bytes())
}
/// Attempts to append a given string slice onto the end of this
/// `ArrayString`.
///
/// # Errors
///
/// Returns an error if the new length would be longer than the capacity of
/// the backing array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("foo");
///
/// s.try_push_str("bar").unwrap();
///
/// assert_eq!("foobar", s);
///
/// assert!(s.try_push_str("hello").is_err());
/// ```
#[inline]
pub fn try_push_str<'other>(
&mut self,
string: &'other str,
) -> Result<(), CapacityOverflowError<&'other str>> {
if self.len() + string.len() > self.capacity() {
Err(CapacityOverflowError {
overflow_amount: self.len() + string.len() - self.capacity(),
inner: string,
})
} else {
self.vec.extend_from_slice(string.as_bytes());
Ok(())
}
}
/// Appends the given [`char`] to the end of this `ArrayString`.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the
/// backing array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("abc");
///
/// s.push('1');
/// s.push('2');
/// s.push('3');
///
/// assert_eq!("abc123", s);
/// ```
#[inline]
pub fn push(&mut self, ch: char) {
match ch.len_utf8() {
1 => self.vec.push(ch as u8),
_ => self
.vec
.extend_from_slice(ch.encode_utf8(&mut [0; 4]).as_bytes()),
}
}
/// Attempts to append the given [`char`] to the end of this `ArrayString`.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Errors
///
/// Returns an error if the new length would be longer than the capacity of
/// the backing array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("abc");
///
/// s.try_push('1').unwrap();
/// s.try_push('2').unwrap();
/// s.try_push('3').unwrap();
///
/// assert_eq!("abc123", s);
///
/// assert!(s.try_push('f').is_err());
/// ```
#[inline]
pub fn try_push(
&mut self,
ch: char,
) -> Result<(), CapacityOverflowError<char>> {
if self.len() + ch.len_utf8() > self.capacity() {
Err(CapacityOverflowError {
overflow_amount: self.len() + ch.len_utf8() - self.capacity(),
inner: ch,
})
} else {
match ch.len_utf8() {
1 => self.vec.push(ch as u8),
_ => self
.vec
.extend_from_slice(ch.encode_utf8(&mut [0; 4]).as_bytes()),
}
Ok(())
}
}
/// Shortens this `ArrayString` to the specified length.
///
/// If `new_len` is greater than the string's current length, this has no
/// effect.
///
/// Note that this method has no effect on the maximum capacity
/// of the string
///
/// # Panics
///
/// Panics if `new_len` does not lie on a [`char`] boundary.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 5]>::from("hello");
///
/// s.truncate(2);
///
/// assert_eq!("he", s);
/// ```
#[inline]
pub fn truncate(&mut self, new_len: usize) {
if new_len <= self.len() {
assert!(self.is_char_boundary(new_len));
self.vec.truncate(new_len)
}
}
/// Removes the last character from the string buffer and returns it.
///
/// Returns [`None`] if this `String` is empty.
///
/// [`None`]: https://doc.rust-lang.org/std/option/enum.Option.html#variant.None
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 3]>::from("foo");
///
/// 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 = self.chars().rev().next()?;
let newlen = self.len() - ch.len_utf8();
self.vec.set_len(newlen);
Some(ch)
}
/// Removes a [`char`] from this `String` at a byte position and returns it.
///
/// This is an `O(n)` operation, as it requires copying every element in the
/// buffer.
///
/// # Panics
///
/// Panics if `idx` is larger than or equal to the `ArrayString`'s length,
/// or if it does not lie on a [`char`] boundary.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 3]>::from("foo");
///
/// 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.vec.as_ptr().add(next),
self.vec.as_mut_ptr().add(idx),
len - next,
);
self.vec.set_len(len - (next - idx));
}
ch
}
/// Retains only the characters specified by the predicate.
///
/// In other words, remove all characters `c` such that `f(c)` returns `false`.
/// This method operates in place, visiting each character exactly once in the
/// original order, and preserves the order of the retained characters.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 9]>::from("f_o_ob_ar");
///
/// s.retain(|c| c != '_');
///
/// assert_eq!(s, "foobar");
/// ```
///
/// The exact order may be useful for tracking external state, like an index.
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 5]>::from("abcde");
/// let keep = [false, true, true, false, true];
/// let mut i = 0;
/// s.retain(|_| (keep[i], i += 1).0);
/// assert_eq!(s, "bce");
/// ```
#[inline]
pub fn retain<F>(&mut self, mut f: F)
where
F: FnMut(char) -> bool,
{
let len = self.len();
let mut del_bytes = 0;
let mut idx = 0;
while idx < len {
let ch =
unsafe { self.get_unchecked(idx..len).chars().next().unwrap() };
let ch_len = ch.len_utf8();
if !f(ch) {
del_bytes += ch_len;
} else if del_bytes > 0 {
unsafe {
ptr::copy(
self.vec.as_ptr().add(idx),
self.vec.as_mut_ptr().add(idx - del_bytes),
ch_len,
);
}
}
// Point idx to the next char
idx += ch_len;
}
if del_bytes > 0 {
self.vec.set_len(len - del_bytes);
}
}
/// Inserts a character into this `ArrayString` at a byte position.
///
/// This is an `O(n)` operation as it requires copying every element in the
/// buffer.
///
/// # Panics
///
/// Panics if `idx` is larger than the `ArrayString`'s length, or if it does
/// not lie on a [`char`] boundary.
///
/// Panics if the new length would be longer than the capacity of the
/// backing array.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 3]>::new();
///
/// s.insert(0, 'f');
/// s.insert(1, 'o');
/// s.insert(2, 'o');
///
/// assert_eq!("foo", s);
/// ```
#[inline]
pub fn insert(&mut self, idx: usize, ch: char) {
assert!(self.is_char_boundary(idx));
let mut bits = [0; 4];
let bits = ch.encode_utf8(&mut bits).as_bytes();
assert!(
self.len() + bits.len() <= self.capacity(),
"ArrayString::insert: capacity overflow"
);
unsafe {
self.insert_bytes(idx, bits);
}
}
/// Attempts to insert a character into this `ArrayString` at a byte
/// position.
///
/// This is an `O(n)` operation as it requires copying every element in the
/// buffer.
///
/// # Panics
///
/// Panics if `idx` is larger than the `ArrayString`'s length, or if it does
/// not lie on a [`char`] boundary.
///
/// # Errors
///
/// Returns an error if the new length would be longer than the capacity of
/// the backing array.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 3]>::new();
///
/// s.try_insert(0, 'f').unwrap();
/// s.try_insert(1, 'o').unwrap();
/// s.try_insert(2, 'o').unwrap();
///
/// assert_eq!("foo", s);
///
/// assert!(s.try_insert(0, 'b').is_err());
/// ```
#[inline]
pub fn try_insert(
&mut self,
idx: usize,
ch: char,
) -> Result<(), CapacityOverflowError<char>> {
assert!(self.is_char_boundary(idx));
let mut bits = [0; 4];
let bits = ch.encode_utf8(&mut bits).as_bytes();
if self.len() + bits.len() > self.capacity() {
Err(CapacityOverflowError {
overflow_amount: self.len() + bits.len() - self.capacity(),
inner: ch,
})
} else {
unsafe {
self.insert_bytes(idx, bits);
}
Ok(())
}
}
/// Inserts a string slice into this `ArrayString` at a byte position.
///
/// This is an `O(n)` operation as it requires copying every element in the
/// buffer.
///
/// # Panics
///
/// Panics if `idx` is larger than the `String`'s length, or if it does not
/// lie on a [`char`] boundary.
///
/// Panics if the new length would be longer than the capacity of the
/// backing array.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("bar");
///
/// s.insert_str(0, "foo");
///
/// assert_eq!("foobar", s);
/// ```
#[inline]
pub fn insert_str(&mut self, idx: usize, string: &str) {
assert!(self.is_char_boundary(idx));
assert!(
self.len() + string.len() <= self.capacity(),
"ArrayString::insert_str: capacity overflow"
);
unsafe {
self.insert_bytes(idx, string.as_bytes());
}
}
/// Attempts to insert a string slice into this `ArrayString` at a byte
/// position.
///
/// This is an `O(n)` operation as it requires copying every element in the
/// buffer.
///
/// # Panics
///
/// Panics if `idx` is larger than the `String`'s length, or if it does not
/// lie on a [`char`] boundary.
///
/// # Errors
///
/// Returns an error if the new length would be longer than the capacity of
/// the backing array.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 6]>::from("bar");
///
/// s.insert_str(0, "foo");
///
/// assert_eq!("foobar", s);
/// ```
#[inline]
pub fn try_insert_str<'other>(
&mut self,
idx: usize,
string: &'other str,
) -> Result<(), CapacityOverflowError<&'other str>> {
assert!(self.is_char_boundary(idx));
if self.len() + string.len() > self.capacity() {
Err(CapacityOverflowError {
overflow_amount: self.len() + string.len() - self.capacity(),
inner: string,
})
} else {
unsafe {
self.insert_bytes(idx, string.as_bytes());
}
Ok(())
}
}
/// Inserts bytes.
///
/// The new length must not overflow the capacity of the backing array.
///
/// The index must be <= the current length.
unsafe fn insert_bytes(&mut self, idx: usize, bytes: &[u8]) {
let len = self.len();
let amt = bytes.len();
ptr::copy(
self.vec.as_ptr().add(idx),
self.vec.as_mut_ptr().add(idx + amt),
len - idx,
);
ptr::copy(bytes.as_ptr(), self.vec.as_mut_ptr().add(idx), amt);
self.vec.set_len(len + amt);
}
/// Truncates this `ArrayString`, removing all contents.
///
/// While this means the `ArrayString` will have a length of zero, it does
/// not modify its capacity.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 3]>::from("foo");
///
/// s.clear();
///
/// assert!(s.is_empty());
/// assert_eq!(0, s.len());
/// assert_eq!(3, s.capacity());
/// ```
#[inline]
pub fn clear(&mut self) {
self.vec.clear()
}
/// Creates a draining iterator that removes the specified range in the
/// `ArrayString` and yields the removed `chars`.
///
/// Note: The element range is removed even if the iterator is not
/// consumed until the end.
///
/// # Panics
///
/// Panics if the starting point or end point do not lie on a [`char`]
/// boundary, or if they're out of bounds.
///
/// [`char`]: https://doc.rust-lang.org/std/primitive.char.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 23]>::from("α is alpha, β is beta");
/// let beta_offset = s.find('β').unwrap_or(s.len());
///
/// // Remove the range up until the β from the string
/// let t: ArrayString<[u8; 23]> = s.drain(..beta_offset).collect();
/// assert_eq!(t, "α is alpha, ");
/// assert_eq!(s, "β is beta");
///
/// // A full range clears the string
/// s.drain(..);
/// assert_eq!(s, "");
/// ```
pub fn drain<R>(&mut self, range: R) -> Drain<'_, A>
where
R: RangeBounds<usize>,
{
use Bound::*;
let len = self.len();
let start = match range.start_bound() {
Included(&n) => n,
Excluded(&n) => n + 1,
Unbounded => 0,
};
let end = match range.end_bound() {
Included(&n) => n + 1,
Excluded(&n) => n,
Unbounded => len,
};
// Take out two simultaneous borrows. The &mut String won't be accessed
// until iteration is over, in Drop.
let self_ptr = self as *mut _;
// slicing does the appropriate bounds checks
let chars_iter = self[start..end].chars();
Drain {
start,
end,
iter: chars_iter,
string: self_ptr,
}
}
/// Removes the specified range in the string,
/// and replaces it with the given string.
/// The given string doesn't need to be the same length as the range.
///
/// # Panics
///
/// Panics if the starting point or end point do not lie on a [`char`]
/// boundary, or if they're out of bounds.
///
/// # Examples
///
/// Basic usage:
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut s = ArrayString::<[u8; 32]>::from("α is alpha, β is beta");
/// let beta_offset = s.find('β').unwrap_or(s.len());
///
/// // Replace the range up until the β from the string
/// s.replace_range(..beta_offset, "Α is capital alpha; ");
/// assert_eq!(s, "Α is capital alpha; β is beta");
/// ```
pub fn replace_range<R>(&mut self, range: R, replace_with: &str)
where
R: RangeBounds<usize>,
{
match range.start_bound() {
Bound::Included(&n) => assert!(self.is_char_boundary(n)),
Bound::Excluded(&n) => assert!(self.is_char_boundary(n + 1)),
Bound::Unbounded => {}
};
match range.end_bound() {
Bound::Included(&n) => assert!(self.is_char_boundary(n + 1)),
Bound::Excluded(&n) => assert!(self.is_char_boundary(n)),
Bound::Unbounded => {}
};
unsafe { self.as_mut_vec() }.splice(range, replace_with.bytes());
}
/// Splits the string into two at the given index.
///
/// Returns a new `ArrayString`. `self` contains bytes `[0, at)`, and
/// the returned `ArrayString` contains bytes `[at, len)`. `at` must be on
/// the boundary of a UTF-8 code point.
///
/// Both `self` and the returned `ArrayString` will have the same capacity
/// as `self` did before this was called.
///
/// # Panics
///
/// Panics if `at` is not on a `UTF-8` code point boundary, or if it is beyond the last
/// code point of the string.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let mut hello = ArrayString::<[u8; 13]>::from("Hello, World!");
/// let world = hello.split_off(7);
/// assert_eq!(hello, "Hello, ");
/// assert_eq!(world, "World!");
/// ```
#[inline]
#[must_use = "use `.truncate()` if you don't need the other half"]
pub fn split_off(&mut self, at: usize) -> ArrayString<A> {
assert!(self.is_char_boundary(at));
// can't use `ArrayVec::split_off` without a `Default` bound
let mut other = ArrayVec::from(A::DEFAULT);
let moves = &mut self.vec[at..];
let split_len = moves.len();
let targets = &mut other[..split_len];
moves.swap_with_slice(targets);
other.set_len(split_len);
self.vec.set_len(at);
unsafe { ArrayString::from_utf8_unchecked(other) }
}
}
impl ArrayString<[u8; 4]> {
/// Creates an `ArrayString` from a `char` infallibly.
///
/// Without const generics, this method is limited to `ArrayString`s with
/// backing arrays of size 4 only.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 4]>::from_char_infallible('c');
/// assert_eq!(s, "c");
/// ```
pub fn from_char_infallible(c: char) -> Self {
let mut arr = [0u8; 4];
let len = c.encode_utf8(&mut arr).len();
unsafe { Self::from_utf8_unchecked(ArrayVec::from_array_len(arr, len)) }
}
}
impl<A: ByteArray> Deref for ArrayString<A> {
type Target = str;
fn deref(&self) -> &str {
unsafe { str::from_utf8_unchecked(&*self.vec) }
}
}
impl<A: ByteArray> DerefMut for ArrayString<A> {
fn deref_mut(&mut self) -> &mut str {
unsafe { str::from_utf8_unchecked_mut(&mut *self.vec) }
}
}
impl<A: ByteArray> fmt::Display for ArrayString<A> {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&**self, f)
}
}
impl<A: ByteArray> fmt::Debug for ArrayString<A> {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&**self, f)
}
}
impl<A: ByteArray> Hash for ArrayString<A> {
#[inline]
fn hash<H: Hasher>(&self, hasher: &mut H) {
(**self).hash(hasher)
}
}
impl<A: ByteArray + Clone> Clone for ArrayString<A> {
fn clone(&self) -> Self {
ArrayString {
vec: self.vec.clone(),
}
}
fn clone_from(&mut self, source: &Self) {
self.vec.clone_from(&source.vec);
}
}
impl<A: ByteArray, A2: ByteArray> FromIterator<ArrayString<A2>>
for ArrayString<A>
{
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn from_iter<I: IntoIterator<Item = ArrayString<A2>>>(iter: I) -> Self {
let mut buf = Self::new();
buf.extend(iter);
buf
}
}
macro_rules! impl_from_iterator {
($(#[$meta:meta])* $ty:ty) => {
$(#[$meta])*
#[allow(unused_lifetimes)]
impl<'a, A: ByteArray> FromIterator<$ty>
for ArrayString<A>
{
/// # Panics
///
/// Panics if the length would be longer than the capacity of the
/// backing array.
fn from_iter<I: IntoIterator<Item = $ty>>(iter: I) -> Self {
let mut buf = Self::new();
buf.extend(iter);
buf
}
}
};
}
impl_from_iterator!(
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")] Cow<'a, str>);
impl_from_iterator!(
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
String
);
impl_from_iterator!(&'a str);
impl_from_iterator!(&'a char);
impl_from_iterator!(char);
impl<A: ByteArray> Extend<char> for ArrayString<A> {
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn extend<I: IntoIterator<Item = char>>(&mut self, iter: I) {
let iterator = iter.into_iter();
iterator.for_each(move |c| self.push(c));
}
}
impl<'a, A: ByteArray> Extend<&'a char> for ArrayString<A> {
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn extend<I: IntoIterator<Item = &'a char>>(&mut self, iter: I) {
self.extend(iter.into_iter().map(|&c| c));
}
}
impl<'a, A: ByteArray> Extend<&'a str> for ArrayString<A> {
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn extend<I: IntoIterator<Item = &'a str>>(&mut self, iter: I) {
iter.into_iter().for_each(move |s| self.push_str(s));
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
impl<A: ByteArray> Extend<String> for ArrayString<A> {
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn extend<I: IntoIterator<Item = String>>(&mut self, iter: I) {
iter.into_iter().for_each(move |s| self.push_str(&s));
}
}
impl<A: ByteArray, A2: ByteArray> Extend<ArrayString<A2>> for ArrayString<A> {
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn extend<I: IntoIterator<Item = ArrayString<A2>>>(&mut self, iter: I) {
iter.into_iter().for_each(move |s| self.push_str(&s));
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
impl<'a, A: ByteArray> Extend<Cow<'a, str>> for ArrayString<A> {
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
fn extend<I: IntoIterator<Item = Cow<'a, str>>>(&mut self, iter: I) {
iter.into_iter().for_each(move |s| self.push_str(&s));
}
}
macro_rules! impl_eq {
($(#[$meta:meta])* $lhs:ty, $rhs: ty) => {
$(#[$meta])*
#[allow(unused_lifetimes)]
impl<'a, 'b, A: ByteArray> PartialEq<$rhs> for $lhs {
#[inline]
fn eq(&self, other: &$rhs) -> bool {
PartialEq::eq(&self[..], &other[..])
}
#[inline]
fn ne(&self, other: &$rhs) -> bool {
PartialEq::ne(&self[..], &other[..])
}
}
$(#[$meta])*
#[allow(unused_lifetimes)]
impl<'a, 'b, A: ByteArray> PartialEq<$lhs> for $rhs {
#[inline]
fn eq(&self, other: &$lhs) -> bool {
PartialEq::eq(&self[..], &other[..])
}
#[inline]
fn ne(&self, other: &$lhs) -> bool {
PartialEq::ne(&self[..], &other[..])
}
}
};
}
impl_eq! { ArrayString<A>, str }
impl_eq! { ArrayString<A>, &'a str }
impl_eq! {
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
ArrayString<A>, Cow<'a, str>
}
impl_eq! {
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
ArrayString<A>, String
}
impl<A1, A2> PartialEq<ArrayString<A1>> for ArrayString<A2>
where
A1: ByteArray,
A2: ByteArray,
{
#[inline]
fn eq(&self, other: &ArrayString<A1>) -> bool {
PartialEq::eq(&self[..], &other[..])
}
#[inline]
fn ne(&self, other: &ArrayString<A1>) -> bool {
PartialEq::ne(&self[..], &other[..])
}
}
/// Implements the `+` operator for concatenating two strings.
///
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use std::convert::TryFrom;
/// let a = ArrayString::<[u8; 13]>::from("Hello, ");
/// let b = "World!";
/// let c = a + b;
/// assert_eq!(c, "Hello, World!");
/// ```
impl<A: ByteArray> Add<&str> for ArrayString<A> {
type Output = ArrayString<A>;
#[inline]
fn add(mut self, other: &str) -> Self {
self.push_str(other);
self
}
}
/// Implements the `+=` operator for appending to a `String`.
///
/// This has the same behavior as the [`push_str`] method.
///
/// # Panics
///
/// Panics if the new length would be longer than the capacity of the backing
/// array.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use std::convert::TryFrom;
/// let mut a = ArrayString::<[u8; 13]>::from("Hello, ");
/// let b = "World!";
/// a += b;
/// assert_eq!(a, "Hello, World!");
/// ```
///
/// [`push_str`]: struct.ArrayString.html#method.push_str
impl<A: ByteArray> AddAssign<&str> for ArrayString<A> {
#[inline]
fn add_assign(&mut self, other: &str) {
self.push_str(other);
}
}
impl<A: ByteArray> ops::Index<ops::Range<usize>> for ArrayString<A> {
type Output = str;
#[inline]
fn index(&self, index: ops::Range<usize>) -> &str {
&self[..][index]
}
}
impl<A: ByteArray> ops::Index<ops::RangeTo<usize>> for ArrayString<A> {
type Output = str;
#[inline]
fn index(&self, index: ops::RangeTo<usize>) -> &str {
&self[..][index]
}
}
impl<A: ByteArray> ops::Index<ops::RangeFrom<usize>> for ArrayString<A> {
type Output = str;
#[inline]
fn index(&self, index: ops::RangeFrom<usize>) -> &str {
&self[..][index]
}
}
impl<A: ByteArray> ops::Index<ops::RangeFull> for ArrayString<A> {
type Output = str;
#[inline]
fn index(&self, _index: ops::RangeFull) -> &str {
unsafe { str::from_utf8_unchecked(&self.vec) }
}
}
impl<A: ByteArray> ops::Index<ops::RangeInclusive<usize>> for ArrayString<A> {
type Output = str;
#[inline]
fn index(&self, index: ops::RangeInclusive<usize>) -> &str {
Index::index(&**self, index)
}
}
impl<A: ByteArray> ops::Index<ops::RangeToInclusive<usize>> for ArrayString<A> {
type Output = str;
#[inline]
fn index(&self, index: ops::RangeToInclusive<usize>) -> &str {
Index::index(&**self, index)
}
}
impl<A: ByteArray> ops::IndexMut<ops::Range<usize>> for ArrayString<A> {
#[inline]
fn index_mut(&mut self, index: ops::Range<usize>) -> &mut str {
&mut self[..][index]
}
}
impl<A: ByteArray> ops::IndexMut<ops::RangeTo<usize>> for ArrayString<A> {
#[inline]
fn index_mut(&mut self, index: ops::RangeTo<usize>) -> &mut str {
&mut self[..][index]
}
}
impl<A: ByteArray> ops::IndexMut<ops::RangeFrom<usize>> for ArrayString<A> {
#[inline]
fn index_mut(&mut self, index: ops::RangeFrom<usize>) -> &mut str {
&mut self[..][index]
}
}
impl<A: ByteArray> ops::IndexMut<ops::RangeFull> for ArrayString<A> {
#[inline]
fn index_mut(&mut self, _index: ops::RangeFull) -> &mut str {
unsafe { str::from_utf8_unchecked_mut(&mut *self.vec) }
}
}
impl<A: ByteArray> ops::IndexMut<ops::RangeInclusive<usize>>
for ArrayString<A>
{
#[inline]
fn index_mut(&mut self, index: ops::RangeInclusive<usize>) -> &mut str {
IndexMut::index_mut(&mut **self, index)
}
}
impl<A: ByteArray> ops::IndexMut<ops::RangeToInclusive<usize>>
for ArrayString<A>
{
#[inline]
fn index_mut(&mut self, index: ops::RangeToInclusive<usize>) -> &mut str {
IndexMut::index_mut(&mut **self, index)
}
}
impl<A: ByteArray> AsRef<str> for ArrayString<A> {
#[inline]
fn as_ref(&self) -> &str {
&*self
}
}
impl<A: ByteArray> AsMut<str> for ArrayString<A> {
#[inline]
fn as_mut(&mut self) -> &mut str {
&mut *self
}
}
impl<A: ByteArray> AsRef<[u8]> for ArrayString<A> {
#[inline]
fn as_ref(&self) -> &[u8] {
self.as_bytes()
}
}
/// An error was caused converting another string type into an [`ArrayString`].
///
/// This type contains the amount by which the capacity was overflown, and the
/// input string (when possible).
///
/// # Examples
/// ```
/// # use tinyvec_string::arraystring::{ArrayString, CapacityOverflowError};
/// use std::convert::TryFrom;
/// let result = ArrayString::<[u8; 3]>::try_from("foobar");
///
/// assert!(result.is_err());
/// let err: CapacityOverflowError<&str> = result.unwrap_err();
///
/// assert_eq!(err.overflow_amount(), 3);
/// assert_eq!(err.into_inner(), "foobar");
/// ```
///
/// [`ArrayString`]: struct.ArrayString.html
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
pub struct CapacityOverflowError<S> {
overflow_amount: usize,
inner: S,
}
impl<S> CapacityOverflowError<S> {
/// Get the amount by which the capacity was overflown, i.e. the amount of
/// extra capacity that would've been needed to store the string.
pub fn overflow_amount(&self) -> usize {
self.overflow_amount
}
/// Retrieve the input string.
///
/// # Examples
///
/// This could be used to retrieve a `String` that failed to convert:
/// ```
/// # #[cfg(feature = "alloc")] {
/// # use tinyvec_string::arraystring::{ArrayString, CapacityOverflowError};
/// use std::convert::TryFrom;
/// let heap_string = String::from("a very long string");
/// let result = ArrayString::<[u8; 5]>::try_from(heap_string);
///
/// assert!(result.is_err());
/// let err: CapacityOverflowError<String> = result.unwrap_err();
/// let return_of_the_heap_string = err.into_inner();
///
/// assert_eq!(return_of_the_heap_string, String::from("a very long string"));
/// # }
/// ```
pub fn into_inner(self) -> S {
self.inner
}
}
impl<S: fmt::Display> fmt::Display for CapacityOverflowError<S> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
r#"Failed to convert "{}" to an ArrayString: capacity overflowed by {} bytes"#,
self.inner, self.overflow_amount
)
}
}
impl<'a, A: ByteArray> TryFrom<&'a str> for ArrayString<A> {
type Error = CapacityOverflowError<&'a str>;
fn try_from(s: &'a str) -> Result<Self, Self::Error> {
let mut arr = A::DEFAULT;
let slice = arr.as_slice_mut();
if s.len() <= slice.len() {
slice[..s.len()].copy_from_slice(s.as_bytes());
unsafe {
Ok(Self::from_utf8_unchecked(ArrayVec::from_array_len(
arr,
s.len(),
)))
}
} else {
Err(CapacityOverflowError {
overflow_amount: s.len() - slice.len(),
inner: s,
})
}
}
}
impl<'a, A: ByteArray> TryFrom<&'a mut str> for ArrayString<A> {
type Error = CapacityOverflowError<&'a mut str>;
fn try_from(s: &'a mut str) -> Result<Self, Self::Error> {
match Self::try_from(&*s) {
Ok(s) => Ok(s),
Err(e) => Err(CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: s,
}),
}
}
}
impl<'c, A: ByteArray> TryFrom<&'c char> for ArrayString<A> {
type Error = CapacityOverflowError<&'c char>;
fn try_from(c: &'c char) -> Result<Self, Self::Error> {
let mut buf = [0u8; 4];
let s = c.encode_utf8(&mut buf);
Self::try_from(&*s).map_err(|e| CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: c,
})
}
}
impl<A: ByteArray> TryFrom<char> for ArrayString<A> {
type Error = CapacityOverflowError<char>;
fn try_from(c: char) -> Result<Self, Self::Error> {
let mut buf = [0u8; 4];
let s = c.encode_utf8(&mut buf);
Self::try_from(&*s).map_err(|e| CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: c,
})
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
impl<'a, A: ByteArray> TryFrom<&'a String> for ArrayString<A> {
type Error = CapacityOverflowError<&'a String>;
fn try_from(s: &'a String) -> Result<Self, Self::Error> {
Self::try_from(s.as_str()).map_err(|e| CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: s,
})
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
impl<A: ByteArray> TryFrom<String> for ArrayString<A> {
type Error = CapacityOverflowError<String>;
fn try_from(s: String) -> Result<Self, Self::Error> {
match Self::try_from(&*s) {
Ok(s) => Ok(s),
Err(e) => Err(CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: s,
}),
}
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "alloc")))]
#[cfg(feature = "alloc")]
impl<'a, A: ByteArray> TryFrom<Cow<'a, str>> for ArrayString<A> {
type Error = CapacityOverflowError<Cow<'a, str>>;
fn try_from(s: Cow<'a, str>) -> Result<Self, Self::Error> {
match Self::try_from(&*s) {
Ok(s) => Ok(s),
Err(e) => Err(CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: s,
}),
}
}
}
impl<A: ByteArray> FromStr for ArrayString<A> {
/// Because of lifetime restrictions, the error type can't return the
/// provided string like the `TryFrom` implementations do.
type Err = CapacityOverflowError<()>;
#[inline]
fn from_str(s: &str) -> Result<Self, Self::Err> {
Self::try_from(s).map_err(|e| CapacityOverflowError {
overflow_amount: e.overflow_amount,
inner: (),
})
}
}
impl<A: ByteArray> fmt::Write for ArrayString<A> {
#[inline]
fn write_str(&mut self, s: &str) -> fmt::Result {
self.try_push_str(s).map_err(|_| fmt::Error::default())
}
#[inline]
fn write_char(&mut self, c: char) -> fmt::Result {
self.try_push(c).map_err(|_| fmt::Error::default())
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "serde")))]
#[cfg(feature = "serde")]
impl<A: ByteArray> serde::Serialize for ArrayString<A> {
/// Serializes the string.
///
/// # Example
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let s = ArrayString::<[u8; 5]>::from("hello");
/// let json = serde_json::to_string(&s);
/// assert!(json.is_ok());
/// assert_eq!(json.unwrap(), "\"hello\"");
/// ```
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
serializer.serialize_str(self.as_str())
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "serde")))]
#[cfg(feature = "serde")]
impl<'de, A: ByteArray> serde::Deserialize<'de> for ArrayString<A> {
/// Deserializes into an `ArrayString`.
///
/// Fails if the string to be deserialized is too long.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let src = "\"hello\"";
/// let parsed = serde_json::from_str::<ArrayString<[u8; 5]>>(src);
/// assert!(parsed.is_ok());
/// assert_eq!("hello", parsed.unwrap());
/// ```
///
/// ```
/// # use tinyvec_string::ArrayString;
/// let src = "\"a much longer string\"";
/// let parsed = serde_json::from_str::<ArrayString<[u8; 5]>>(src);
/// assert!(parsed.is_err());
/// ```
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
use core::marker::PhantomData;
struct ArrayStringVisitor<A>(PhantomData<fn() -> A>);
impl<'de, A: ByteArray> serde::de::Visitor<'de> for ArrayStringVisitor<A> {
type Value = ArrayString<A>;
fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "a string up to length {}", A::CAPACITY)
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: serde::de::Error,
{
ArrayString::try_from(v)
.map_err(|_| E::invalid_length(v.len(), &self))
}
}
deserializer.deserialize_str(ArrayStringVisitor(PhantomData))
}
}
/// A possible error value when converting an [`ArrayString`] from a UTF-8 byte
/// vector.
///
/// This type is the error type for the [`from_utf8`] method on `ArrayString`.
/// The [`into_bytes`] method will give back the byte vector that was used in
/// the conversion attempt.
///
/// [`from_utf8`]: struct.ArrayString.html#method.from_utf8
/// [`ArrayString`]: struct.ArrayString.html
/// [`into_bytes`]: struct.FromUtf8Error.html#method.into_bytes
///
/// The [`Utf8Error`] type provided by [`std::str`] represents an error that may
/// occur when converting a slice of [`u8`]s to a [`&str`]. In this sense, it's
/// an analogue to `FromUtf8Error`, and you can get one from a `FromUtf8Error`
/// through the [`utf8_error`] method.
///
/// [`Utf8Error`]: https://doc.rust-lang.org/std/str/struct.Utf8Error.html
/// [`std::str`]: https://doc.rust-lang.org/std/str/index.html
/// [`u8`]: https://doc.rust-lang.org/std/primitive.u8.html
/// [`&str`]: https://doc.rust-lang.org/std/primitive.str.html
/// [`utf8_error`]: struct.FromUtf8Error.html#method.utf8_error
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
/// // some invalid bytes, in a vector
/// let bytes: ArrayVec<[u8; 2]> = array_vec![0, 159];
///
/// let value = ArrayString::from_utf8(bytes);
///
/// assert_eq!(Err(array_vec![0, 159]), value.map_err(|e| e.into_bytes()));
/// ```
#[derive(Clone, Copy, PartialEq, Eq)]
pub struct FromUtf8Error<A: ByteArray> {
pub(crate) vec: ArrayVec<A>,
pub(crate) error: Utf8Error,
}
impl<A: ByteArray> FromUtf8Error<A> {
/// Returns a slice of [`u8`]s bytes that were attempted to convert to an
/// `ArrayString`.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
/// // some invalid bytes, in a vector
/// let bytes: ArrayVec<[u8; 2]> = array_vec![0, 159];
///
/// let value = ArrayString::from_utf8(bytes);
///
/// assert_eq!(&[0, 159], value.unwrap_err().as_bytes());
/// ```
pub fn as_bytes(&self) -> &[u8] {
&self.vec[..]
}
/// Returns the bytes that were attempted to convert to a `String`.
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
/// // some invalid bytes, in a vector
/// let bytes: ArrayVec<[u8; 2]> = array_vec![0, 159];
///
/// let value = ArrayString::from_utf8(bytes);
///
/// assert_eq!(array_vec![0, 159], value.unwrap_err().into_bytes());
/// ```
pub fn into_bytes(self) -> ArrayVec<A> {
self.vec
}
/// Fetch a `Utf8Error` to get more details about the conversion failure.
///
/// The [`Utf8Error`] type provided by [`std::str`] represents an error that may
/// occur when converting a slice of [`u8`]s to a [`&str`]. In this sense, it's
/// an analogue to `FromUtf8Error`. See its documentation for more details
/// on using it.
///
/// [`Utf8Error`]: https://doc.rust-lang.org/std/str/struct.Utf8Error.html
/// [`std::str`]: https://doc.rust-lang.org/std/str/index.html
/// [`u8`]: https://doc.rust-lang.org/std/primitive.u8.html
/// [`&str`]: https://doc.rust-lang.org/std/primitive.str.html
///
/// # Examples
///
/// ```
/// # use tinyvec_string::ArrayString;
/// use tinyvec::{array_vec, ArrayVec};
/// // some invalid bytes, in a vector
/// let bytes: ArrayVec<[u8; 2]> = array_vec![0, 159];
///
/// let error = ArrayString::from_utf8(bytes).unwrap_err().utf8_error();
///
/// // the first byte is invalid here
/// assert_eq!(1, error.valid_up_to());
/// ```
pub fn utf8_error(&self) -> Utf8Error {
self.error
}
}
impl<A: ByteArray> fmt::Debug for FromUtf8Error<A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("FromUtf8Error")
.field("vec", &self.vec)
.field("error", &self.error)
.finish()
}
}
impl<A: ByteArray> fmt::Display for FromUtf8Error<A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.error, f)
}
}
#[cfg_attr(docs_rs, doc(cfg(target_feature = "std")))]
#[cfg(feature = "std")]
impl<A: ByteArray> std::error::Error for FromUtf8Error<A> {}
/// A draining iterator for [`ArrayString`].
///
/// This struct is created by the [`drain`] method on [`ArrayString`]. See its
/// documentation for more.
///
/// [`drain`]: struct.ArrayString.html#method.drain
/// [`ArrayString`]: struct.ArrayString.html
pub struct Drain<'a, A: ByteArray> {
/// Will be used as &'a mut ArrayString in the destructor
string: *mut ArrayString<A>,
/// Start of part to remove
start: usize,
/// End of part to remove
end: usize,
/// Current remaining range to remove
iter: Chars<'a>,
}
impl<A: ByteArray> fmt::Debug for Drain<'_, A> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.pad("Drain { .. }")
}
}
unsafe impl<A: ByteArray> Send for Drain<'_, A> {}
unsafe impl<A: ByteArray> Sync for Drain<'_, A> {}
impl<A: ByteArray> Drop for Drain<'_, A> {
fn drop(&mut self) {
unsafe {
// Use Vec::drain. "Reaffirm" the bounds checks to avoid
// panic code being inserted again.
let self_vec = (*self.string).as_mut_vec();
if self.start <= self.end && self.end <= self_vec.len() {
self_vec.drain(self.start..self.end);
}
}
}
}
impl<A: ByteArray> Iterator for Drain<'_, A> {
type Item = char;
#[inline]
fn next(&mut self) -> Option<char> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
#[inline]
fn last(mut self) -> Option<char> {
self.next_back()
}
}
impl<A: ByteArray> DoubleEndedIterator for Drain<'_, A> {
#[inline]
fn next_back(&mut self) -> Option<char> {
self.iter.next_back()
}
}
impl<A: ByteArray> FusedIterator for Drain<'_, A> {}