Struct encode_unicode::Utf16Char[][src]

pub struct Utf16Char { /* fields omitted */ }

An unicode codepoint stored as UTF-16.

It can be borrowed as an u16 slice, and has the same size as char.

Methods

impl Utf16Char
[src]

Validate and store the first UTF-16 codepoint in the slice. Also return how many units were needed.

Store the first UTF-16 codepoint of the slice.

Safety

The slice must be non-empty and start with a valid UTF-16 codepoint.
The length of the slice is never checked.

Validate and store a UTF-16 pair as returned from char.to_utf16_tuple().

Create an Utf16Char from a tuple as returned from char.to_utf16_tuple().

Safety

The units must represent a single valid codepoint.

Returns 1 or 2. There is no .is_emty() because it would always return false.

Checks that the codepoint is an ASCII character.

Checks that two characters are an ASCII case-insensitive match.

Is equivalent to a.to_ascii_lowercase() == b.to_ascii_lowercase().

Converts the character to its ASCII upper case equivalent.

ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.

Converts the character to its ASCII lower case equivalent.

ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', but non-ASCII letters are unchanged.

Converts the character to its ASCII upper case equivalent in-place.

ASCII letters 'a' to 'z' are mapped to 'A' to 'Z', but non-ASCII letters are unchanged.

Converts the character to its ASCII lower case equivalent in-place.

ASCII letters 'A' to 'Z' are mapped to 'a' to 'z', but non-ASCII letters are unchanged.

Convert from UTF-16 to UTF-32

Write the internal representation to a slice, and then returns the number of u16s written.

Panics

Will panic the buffer is too small; You can get the required length from .len(), but a buffer of length two is always large enough.

The second u16 is used for surrogate pairs.

Methods from Deref<Target = [u16]>

Returns the number of elements in the slice.

Examples

let a = [1, 2, 3];
assert_eq!(a.len(), 3);

Returns true if the slice has a length of 0.

Examples

let a = [1, 2, 3];
assert!(!a.is_empty());

Returns the first element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&10), v.first());

let w: &[i32] = &[];
assert_eq!(None, w.first());

Returns the first and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first() {
    assert_eq!(first, &0);
    assert_eq!(elements, &[1, 2]);
}

Returns the last and all the rest of the elements of the slice, or None if it is empty.

Examples

let x = &[0, 1, 2];

if let Some((last, elements)) = x.split_last() {
    assert_eq!(last, &2);
    assert_eq!(elements, &[0, 1]);
}

Returns the last element of the slice, or None if it is empty.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&30), v.last());

let w: &[i32] = &[];
assert_eq!(None, w.last());

Returns a reference to an element or subslice depending on the type of index.

  • If given a position, returns a reference to the element at that position or None if out of bounds.
  • If given a range, returns the subslice corresponding to that range, or None if out of bounds.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&40), v.get(1));
assert_eq!(Some(&[10, 40][..]), v.get(0..2));
assert_eq!(None, v.get(3));
assert_eq!(None, v.get(0..4));

Returns a reference to an element or subslice, without doing bounds checking.

This is generally not recommended, use with caution! For a safe alternative see get.

Examples

let x = &[1, 2, 4];

unsafe {
    assert_eq!(x.get_unchecked(1), &2);
}

Returns a raw pointer to the slice's buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the container referenced by this slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Examples

let x = &[1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
    for i in 0..x.len() {
        assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize));
    }
}

Returns an iterator over the slice.

Examples

let x = &[1, 2, 4];
let mut iterator = x.iter();

assert_eq!(iterator.next(), Some(&1));
assert_eq!(iterator.next(), Some(&2));
assert_eq!(iterator.next(), Some(&4));
assert_eq!(iterator.next(), None);

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Panics

Panics if size is 0.

Examples

let slice = ['r', 'u', 's', 't'];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), &['r', 'u']);
assert_eq!(iter.next().unwrap(), &['u', 's']);
assert_eq!(iter.next().unwrap(), &['s', 't']);
assert!(iter.next().is_none());

If the slice is shorter than size:

let slice = ['f', 'o', 'o'];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

Returns an iterator over chunk_size elements of the slice at a time. The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

See exact_chunks for a variant of this iterator that returns chunks of always exactly chunk_size elements.

Panics

Panics if chunk_size is 0.

Examples

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert_eq!(iter.next().unwrap(), &['m']);
assert!(iter.next().is_none());

🔬 This is a nightly-only experimental API. (exact_chunks)

Returns an iterator over chunk_size elements of the slice at a time. The chunks are slices and do not overlap. If chunk_size does not divide the length of the slice, then the last up to chunk_size-1 elements will be omitted and can be retrieved from the remainder function of the iterator.

Due to each chunk having exactly chunk_size elements, the compiler can often optimize the resulting code better than in the case of chunks.

Panics

Panics if chunk_size is 0.

Examples

#![feature(exact_chunks)]

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.exact_chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert!(iter.next().is_none());

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len.

Examples

let v = [1, 2, 3, 4, 5, 6];

{
   let (left, right) = v.split_at(0);
   assert!(left == []);
   assert!(right == [1, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(2);
    assert!(left == [1, 2]);
    assert!(right == [3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at(6);
    assert!(left == [1, 2, 3, 4, 5, 6]);
    assert!(right == []);
}

Returns an iterator over subslices separated by elements that match pred. The matched element is not contained in the subslices.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:

let slice = [10, 40, 33];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[]);
assert!(iter.next().is_none());

If two matched elements are directly adjacent, an empty slice will be present between them:

let slice = [10, 6, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10]);
assert_eq!(iter.next().unwrap(), &[]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

Returns an iterator over subslices separated by elements that match pred, starting at the end of the slice and working backwards. The matched element is not contained in the subslices.

Examples

let slice = [11, 22, 33, 0, 44, 55];
let mut iter = slice.rsplit(|num| *num == 0);

assert_eq!(iter.next().unwrap(), &[44, 55]);
assert_eq!(iter.next().unwrap(), &[11, 22, 33]);
assert_eq!(iter.next(), None);

As with split(), if the first or last element is matched, an empty slice will be the first (or last) item returned by the iterator.

let v = &[0, 1, 1, 2, 3, 5, 8];
let mut it = v.rsplit(|n| *n % 2 == 0);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next().unwrap(), &[3, 5]);
assert_eq!(it.next().unwrap(), &[1, 1]);
assert_eq!(it.next().unwrap(), &[]);
assert_eq!(it.next(), None);

Returns an iterator over subslices separated by elements that match pred, limited to returning at most n items. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once by numbers divisible by 3 (i.e. [10, 40], [20, 60, 50]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.splitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

Returns an iterator over subslices separated by elements that match pred limited to returning at most n items. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once, starting from the end, by numbers divisible by 3 (i.e. [50], [10, 40, 30, 20]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.rsplitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

Returns true if the slice contains an element with the given value.

Examples

let v = [10, 40, 30];
assert!(v.contains(&30));
assert!(!v.contains(&50));

Returns true if needle is a prefix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
assert!(!v.starts_with(&[50]));
assert!(!v.starts_with(&[10, 50]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.starts_with(&[]));
let v: &[u8] = &[];
assert!(v.starts_with(&[]));

Returns true if needle is a suffix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
assert!(!v.ends_with(&[50]));
assert!(!v.ends_with(&[50, 30]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.ends_with(&[]));
let v: &[u8] = &[];
assert!(v.ends_with(&[]));

Binary searches this sorted slice for a given element.

If the value is found then Ok is returned, containing the index of the matching element; if the value is not found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

assert_eq!(s.binary_search(&13),  Ok(9));
assert_eq!(s.binary_search(&4),   Err(7));
assert_eq!(s.binary_search(&100), Err(13));
let r = s.binary_search(&1);
assert!(match r { Ok(1..=4) => true, _ => false, });

Binary searches this sorted slice with a comparator function.

The comparator function should implement an order consistent with the sort order of the underlying slice, returning an order code that indicates whether its argument is Less, Equal or Greater the desired target.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

let seek = 13;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
let seek = 4;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
let seek = 100;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
let seek = 1;
let r = s.binary_search_by(|probe| probe.cmp(&seek));
assert!(match r { Ok(1..=4) => true, _ => false, });

Binary searches this sorted slice with a key extraction function.

Assumes that the slice is sorted by the key, for instance with sort_by_key using the same key extraction function.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Examples

Looks up a series of four elements in a slice of pairs sorted by their second elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1, 4].

let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1),
         (1, 2), (2, 3), (4, 5), (5, 8), (3, 13),
         (1, 21), (2, 34), (4, 55)];

assert_eq!(s.binary_search_by_key(&13, |&(a,b)| b),  Ok(9));
assert_eq!(s.binary_search_by_key(&4, |&(a,b)| b),   Err(7));
assert_eq!(s.binary_search_by_key(&100, |&(a,b)| b), Err(13));
let r = s.binary_search_by_key(&1, |&(a,b)| b);
assert!(match r { Ok(1..=4) => true, _ => false, });

🔬 This is a nightly-only experimental API. (slice_align_to)

Transmute the slice to a slice of another type, ensuring aligment of the types is maintained.

This method splits the slice into three distinct slices: prefix, correctly aligned middle slice of a new type, and the suffix slice. The middle slice will have the greatest length possible for a given type and input slice.

This method has no purpose when either input element T or output element U are zero-sized and will return the original slice without splitting anything.

Unsafety

This method is essentially a transmute with respect to the elements in the returned middle slice, so all the usual caveats pertaining to transmute::<T, U> also apply here.

Examples

Basic usage:

unsafe {
    let bytes: [u8; 7] = [1, 2, 3, 4, 5, 6, 7];
    let (prefix, shorts, suffix) = bytes.align_to::<u16>();
    // less_efficient_algorithm_for_bytes(prefix);
    // more_efficient_algorithm_for_aligned_shorts(shorts);
    // less_efficient_algorithm_for_bytes(suffix);
}

Trait Implementations

impl From<Utf16Char> for Utf8Char
[src]

Performs the conversion.

impl Default for Utf16Char
[src]

Returns the "default value" for a type. Read more

impl PartialEq for Utf16Char
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl Eq for Utf16Char
[src]

impl Clone for Utf16Char
[src]

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl Copy for Utf16Char
[src]

impl From<char> for Utf16Char
[src]

Performs the conversion.

impl From<Utf8Char> for Utf16Char
[src]

Performs the conversion.

impl From<Utf16Char> for char
[src]

Performs the conversion.

impl IntoIterator for Utf16Char
[src]

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Important traits for Utf16Iterator

Iterate over the units.

impl Extend<Utf16Char> for Vec<u16>
[src]

Extends a collection with the contents of an iterator. Read more

impl FromIterator<Utf16Char> for Vec<u16>
[src]

Creates a value from an iterator. Read more

impl AsRef<[u16]> for Utf16Char
[src]

Performs the conversion.

impl Borrow<[u16]> for Utf16Char
[src]

Immutably borrows from an owned value. Read more

impl Deref for Utf16Char
[src]

The resulting type after dereferencing.

Dereferences the value.

impl AsciiExt for Utf16Char
[src]

Deprecated since 1.26.0

: use inherent methods instead

Container type for copied ASCII characters.

Deprecated since 1.26.0

: use inherent methods instead

Checks if the value is within the ASCII range. Read more

Deprecated since 1.26.0

: use inherent methods instead

Checks that two values are an ASCII case-insensitive match. Read more

Deprecated since 1.26.0

: use inherent methods instead

Makes a copy of the value in its ASCII upper case equivalent. Read more

Deprecated since 1.26.0

: use inherent methods instead

Makes a copy of the value in its ASCII lower case equivalent. Read more

Deprecated since 1.26.0

: use inherent methods instead

Converts this type to its ASCII upper case equivalent in-place. Read more

Deprecated since 1.26.0

: use inherent methods instead

Converts this type to its ASCII lower case equivalent in-place. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII alphabetic character: U+0041 'A' ... U+005A 'Z' or U+0061 'a' ... U+007A 'z'. For strings, true if all characters in the string are ASCII alphabetic. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII uppercase character: U+0041 'A' ... U+005A 'Z'. For strings, true if all characters in the string are ASCII uppercase. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII lowercase character: U+0061 'a' ... U+007A 'z'. For strings, true if all characters in the string are ASCII lowercase. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII alphanumeric character: U+0041 'A' ... U+005A 'Z', U+0061 'a' ... U+007A 'z', or U+0030 '0' ... U+0039 '9'. For strings, true if all characters in the string are ASCII alphanumeric. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII decimal digit: U+0030 '0' ... U+0039 '9'. For strings, true if all characters in the string are ASCII digits. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII hexadecimal digit: U+0030 '0' ... U+0039 '9', U+0041 'A' ... U+0046 'F', or U+0061 'a' ... U+0066 'f'. For strings, true if all characters in the string are ASCII hex digits. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII punctuation character: Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII graphic character: U+0021 '!' ... U+007E '~'. For strings, true if all characters in the string are ASCII graphic characters. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII whitespace character: U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED, U+000C FORM FEED, or U+000D CARRIAGE RETURN. For strings, true if all characters in the string are ASCII whitespace. Read more

Deprecated since 1.26.0

: use inherent methods instead

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII control character: U+0000 NUL ... U+001F UNIT SEPARATOR, or U+007F DELETE. Note that most ASCII whitespace characters are control characters, but SPACE is not. Read more

impl Hash for Utf16Char
[src]

Feeds this value into the given [Hasher]. Read more

Feeds a slice of this type into the given [Hasher]. Read more

impl Debug for Utf16Char
[src]

Formats the value using the given formatter. Read more

impl Display for Utf16Char
[src]

Formats the value using the given formatter. Read more

impl PartialOrd for Utf16Char
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl Ord for Utf16Char
[src]

This method returns an Ordering between self and other. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

impl From<Utf16Char> for Utf16Iterator
[src]

Performs the conversion.

Auto Trait Implementations

impl Send for Utf16Char

impl Sync for Utf16Char