Trait UnicodeScalar

pub trait UnicodeScalar {
    const MIN: Self;
    const MAX: Self;

    // Required methods
    fn byte_len(self) -> usize ;
    fn len_utf8(self) -> usize ;
    fn len_utf16(self) -> usize ;
    fn encode_utf8(self, dst: &mut [u8]) -> &mut str ;
    fn to_utf8_bytes(self) -> [u8; 4];
    fn encode_utf16(self, dst: &mut [u16]) -> &mut [u16] ;
    fn to_digit(self, radix: u32) -> Option<u32> ;
    fn to_ascii_uppercase(self) -> Self
       where Self: Sized;
    fn to_ascii_lowercase(self) -> Self
       where Self: Sized;
    fn is_noncharacter(self) -> bool;
    fn is_digit(self, radix: u32) -> bool;
    fn is_control(self) -> bool;
    fn is_nul(self) -> bool;
    fn is_alphabetic(self) -> bool;
    fn is_numeric(self) -> bool;
    fn is_alphanumeric(self) -> bool;
    fn is_lowercase(self) -> bool;
    fn is_uppercase(self) -> bool;
    fn is_whitespace(self) -> bool;
    fn is_ascii(self) -> bool;

    // Provided method
    fn is_character(self) -> bool
       where Self: Sized { ... }
}

Common trait for unicode scalar types.

It’s implemented for: char7, char8, char16, and char.

Required Associated Constants

const MIN: Self

The lowest unicode scalar that can be represented.

const MAX: Self

The highest unicode scalar that can be represented.

Required Methods

fn byte_len(self) -> usize

Returns the number of bytes needed to represent the scalar value.

fn len_utf8(self) -> usize

Returns the number of bytes needed to encode in UTF-8.

fn len_utf16(self) -> usize

Returns the number of bytes needed to encode in UTF-16.

fn encode_utf8(self, dst: &mut [u8]) -> &mut str

Encodes this scalar as UTF-8 into the provided byte buffer, and then returns the subslice of the buffer that contains the encoded scalar.

Panics

Panics if the buffer is not large enough. A buffer of length four is large enough to encode any char.

fn to_utf8_bytes(self) -> [u8; 4]

Converts this scalar to an UTF-8 encoded sequence of bytes.

Note that this function always returns a 4-byte array, but the actual UTF-8 sequence may be shorter. The unused bytes are set to 0.

fn encode_utf16(self, dst: &mut [u16]) -> &mut [u16]

Encodes this scalar as UTF-16 into the provided byte buffer, and then returns the subslice of the buffer that contains the encoded scalar.

Panics

Panics if the buffer is not large enough. A buffer of length 2 is large enough to encode any char.

fn to_digit(self, radix: u32) -> Option<u32>

Converts the scalar to a digit in the given radix.

‘Digit’ is defined to be only the following characters: 0-9, a-z, A-Z.

Errors

Returns None if the char does not refer to a digit in the given radix.

Panics

Panics if given a radix larger than 36.

fn to_ascii_uppercase(self) -> Self

where Self: Sized,

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

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

fn to_ascii_lowercase(self) -> Self

where Self: Sized,

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

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

fn is_noncharacter(self) -> bool

Returns true if this unicode scalar is a noncharacter.

fn is_digit(self, radix: u32) -> bool

Checks if the unicode scalar is a digit in the given radix.

See also to_digit.

fn is_control(self) -> bool

Returns true if this unicode scalar has the general category for control codes.

fn is_nul(self) -> bool

Returns true if this unicode scalar is the nul character (0x00).

fn is_alphabetic(self) -> bool

Returns true if this unicode scalar has the Alphabetic property.

fn is_numeric(self) -> bool

Returns true if this unicode scalar has one of the general categories for numbers.

If you want to parse ASCII decimal digits (0-9) or ASCII base-N, use is_ascii_digit or is_digit instead.

fn is_alphanumeric(self) -> bool

Returns true if this unicode scalar satisfies either is_alphabetic() or is_numeric().

fn is_lowercase(self) -> bool

Returns true if this unicode scalar has the Lowercase property.

fn is_uppercase(self) -> bool

Returns true if this unicode scalar has the Lowercase property.

fn is_whitespace(self) -> bool

Returns true if this unicode scalar has the White_Space property.

fn is_ascii(self) -> bool

Checks if the value is within the ASCII range.

Provided Methods

fn is_character(self) -> bool

where Self: Sized,

Returns true if this unicode scalar is an abstract character.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl UnicodeScalar for char

const MIN: Self = '\0'

const MAX: Self = '\u{10ffff}'

fn byte_len(self) -> usize

fn len_utf8(self) -> usize

fn len_utf16(self) -> usize

fn encode_utf8(self, dst: &mut [u8]) -> &mut str

fn to_utf8_bytes(self) -> [u8; 4]

fn encode_utf16(self, dst: &mut [u16]) -> &mut [u16]

fn to_digit(self, radix: u32) -> Option<u32>

fn to_ascii_uppercase(self) -> char

fn to_ascii_lowercase(self) -> char

fn is_noncharacter(self) -> bool

fn is_digit(self, radix: u32) -> bool

fn is_control(self) -> bool

fn is_nul(self) -> bool

fn is_alphabetic(self) -> bool

fn is_numeric(self) -> bool

fn is_alphanumeric(self) -> bool

fn is_lowercase(self) -> bool

fn is_uppercase(self) -> bool

fn is_whitespace(self) -> bool

fn is_ascii(self) -> bool

Implementors

impl UnicodeScalar for char7

const MIN: Self = Self::MIN

const MAX: Self = Self::MAX

impl UnicodeScalar for char8

const MIN: Self = Self::MIN

const MAX: Self = Self::MAX

impl UnicodeScalar for char16

const MIN: Self = Self::MIN

const MAX: Self = Self::MAX