Trait encode_unicode::CharExt
source · pub trait CharExt: Sized {
Show 13 methods
// Required methods
fn to_utf8(self) -> Utf8Char;
fn to_utf16(self) -> Utf16Char;
fn iter_utf8_bytes(self) -> Utf8Iterator ⓘ;
fn iter_utf16_units(self) -> Utf16Iterator ⓘ;
fn to_utf8_array(self) -> ([u8; 4], usize);
fn to_utf16_tuple(self) -> (u16, Option<u16>);
fn from_utf8_slice_start(
src: &[u8],
) -> Result<(Self, usize), InvalidUtf8Slice>;
fn from_utf16_slice_start(
src: &[u16],
) -> Result<(Self, usize), InvalidUtf16Slice>;
fn from_utf8_array(utf8: [u8; 4]) -> Result<Self, InvalidUtf8Array>;
fn from_utf16_tuple(
utf16: (u16, Option<u16>),
) -> Result<Self, InvalidUtf16Tuple>;
unsafe fn from_utf8_exact_slice_unchecked(src: &[u8]) -> Self;
unsafe fn from_utf16_tuple_unchecked(utf16: (u16, Option<u16>)) -> Self;
fn from_u32_detailed(c: u32) -> Result<Self, InvalidCodepoint>;
}
Expand description
Extension trait for char
that adds methods for converting to and from UTF-8 or UTF-16.
Required Methods§
sourcefn to_utf8(self) -> Utf8Char
fn to_utf8(self) -> Utf8Char
Get the UTF-8 representation of this codepoint.
Utf8Char
is to [u8;4]
what char
is to u32
:
a restricted type that cannot be mutated internally.
sourcefn to_utf16(self) -> Utf16Char
fn to_utf16(self) -> Utf16Char
Get the UTF-16 representation of this codepoint.
Utf16Char
is to [u16;2]
what char
is to u32
:
a restricted type that cannot be mutated internally.
sourcefn iter_utf8_bytes(self) -> Utf8Iterator ⓘ
fn iter_utf8_bytes(self) -> Utf8Iterator ⓘ
Iterate over or read the one to four bytes in the UTF-8 representation of this codepoint.
An identical alternative to the unstable char.encode_utf8()
.
That method somehow still exist on stable, so I have to use a different name.
sourcefn iter_utf16_units(self) -> Utf16Iterator ⓘ
fn iter_utf16_units(self) -> Utf16Iterator ⓘ
Iterate over the one or two units in the UTF-16 representation of this codepoint.
An identical alternative to the unstable char.encode_utf16()
.
That method somehow still exist on stable, so I have to use a different name.
sourcefn to_utf8_array(self) -> ([u8; 4], usize)
fn to_utf8_array(self) -> ([u8; 4], usize)
Convert this char to an UTF-8 array, and also return how many bytes of the array are used,
The returned array is left-aligned with unused bytes set to zero.
sourcefn to_utf16_tuple(self) -> (u16, Option<u16>)
fn to_utf16_tuple(self) -> (u16, Option<u16>)
Convert this char
to UTF-16.
The second u16
is Some
if a surrogate pair is required.
sourcefn from_utf8_slice_start(src: &[u8]) -> Result<(Self, usize), InvalidUtf8Slice>
fn from_utf8_slice_start(src: &[u8]) -> Result<(Self, usize), InvalidUtf8Slice>
Create a char
from the start of an UTF-8 slice,
and also return how many bytes were used.
§Errors
Returns an Err
if the slice is empty, doesn’t start with a valid
UTF-8 sequence or is too short for the sequence.
§Examples
use encode_unicode::CharExt;
use encode_unicode::error::InvalidUtf8Slice::*;
use encode_unicode::error::InvalidUtf8::*;
assert_eq!(char::from_utf8_slice_start(&[b'A', b'B', b'C']), Ok(('A',1)));
assert_eq!(char::from_utf8_slice_start(&[0xdd, 0xbb]), Ok(('\u{77b}',2)));
assert_eq!(char::from_utf8_slice_start(&[]), Err(TooShort(1)));
assert_eq!(char::from_utf8_slice_start(&[0xf0, 0x99]), Err(TooShort(4)));
assert_eq!(char::from_utf8_slice_start(&[0xee, b'F', 0x80]), Err(Utf8(NotAContinuationByte(1))));
assert_eq!(char::from_utf8_slice_start(&[0xee, 0x99, 0x0f]), Err(Utf8(NotAContinuationByte(2))));
sourcefn from_utf16_slice_start(
src: &[u16],
) -> Result<(Self, usize), InvalidUtf16Slice>
fn from_utf16_slice_start( src: &[u16], ) -> Result<(Self, usize), InvalidUtf16Slice>
Create a char
from the start of an UTF-16 slice,
and also return how many units were used.
If you want to continue after an error, continue with the next u16
unit.
sourcefn from_utf8_array(utf8: [u8; 4]) -> Result<Self, InvalidUtf8Array>
fn from_utf8_array(utf8: [u8; 4]) -> Result<Self, InvalidUtf8Array>
Convert an UTF-8 sequence as returned from .to_utf8_array()
into a char
The codepoint must start at the first byte, and leftover bytes are ignored.
§Errors
Returns an Err
if the array doesn’t start with a valid UTF-8 sequence.
§Examples
use encode_unicode::CharExt;
use encode_unicode::error::InvalidUtf8Array::*;
use encode_unicode::error::InvalidUtf8::*;
use encode_unicode::error::InvalidCodepoint::*;
assert_eq!(char::from_utf8_array([b'A', 0, 0, 0]), Ok('A'));
assert_eq!(char::from_utf8_array([0xf4, 0x8b, 0xbb, 0xbb]), Ok('\u{10befb}'));
assert_eq!(char::from_utf8_array([b'A', b'B', b'C', b'D']), Ok('A'));
assert_eq!(char::from_utf8_array([0, 0, 0xcc, 0xbb]), Ok('\0'));
assert_eq!(char::from_utf8_array([0xef, b'F', 0x80, 0x80]), Err(Utf8(NotAContinuationByte(1))));
assert_eq!(char::from_utf8_array([0xc1, 0x80, 0, 0]), Err(Utf8(OverLong)));
assert_eq!(char::from_utf8_array([0xf7, 0xaa, 0x99, 0x88]), Err(Codepoint(TooHigh)));
sourcefn from_utf16_tuple(
utf16: (u16, Option<u16>),
) -> Result<Self, InvalidUtf16Tuple>
fn from_utf16_tuple( utf16: (u16, Option<u16>), ) -> Result<Self, InvalidUtf16Tuple>
Convert a UTF-16 pair as returned from .to_utf16_tuple()
into a char
.
sourceunsafe fn from_utf8_exact_slice_unchecked(src: &[u8]) -> Self
unsafe fn from_utf8_exact_slice_unchecked(src: &[u8]) -> Self
Convert an UTF-8 sequence into a char.
The length of the slice is taken as length of the sequence; it should be 1,2,3 or 4.
§Safety
The slice must contain exactly one, valid, UTF-8 sequence.
Passing a slice that produces an invalid codepoint is always undefined behavior; Later checks that the codepoint is valid can be removed by the compiler.
§Panics
If the slice is empty
sourceunsafe fn from_utf16_tuple_unchecked(utf16: (u16, Option<u16>)) -> Self
unsafe fn from_utf16_tuple_unchecked(utf16: (u16, Option<u16>)) -> Self
Convert a UTF-16 tuple as returned from .to_utf16_tuple()
into a char
.
sourcefn from_u32_detailed(c: u32) -> Result<Self, InvalidCodepoint>
fn from_u32_detailed(c: u32) -> Result<Self, InvalidCodepoint>
Perform some extra validations compared to char::from_u32_unchecked()
§Errors
This function will return an error if
- the value is greater than 0x10ffff
- the value is between 0xd800 and 0xdfff (inclusive)