1.0.0[−]Primitive Type char
A character type.
The char
type represents a single character. More specifically, since
'character' isn't a well-defined concept in Unicode, char
is a 'Unicode
scalar value', which is similar to, but not the same as, a 'Unicode code
point'.
This documentation describes a number of methods and trait implementations on the
char
type. For technical reasons, there is additional, separate
documentation in the std::char
module as well.
Representation
char
is always four bytes in size. This is a different representation than
a given character would have as part of a String
. For example:
let v = vec!['h', 'e', 'l', 'l', 'o']; // five elements times four bytes for each element assert_eq!(20, v.len() * std::mem::size_of::<char>()); let s = String::from("hello"); // five elements times one byte per element assert_eq!(5, s.len() * std::mem::size_of::<u8>());Run
As always, remember that a human intuition for 'character' may not map to Unicode's definitions. For example, despite looking similar, the 'é' character is one Unicode code point while 'é' is two Unicode code points:
let mut chars = "é".chars(); // U+00e9: 'latin small letter e with acute' assert_eq!(Some('\u{00e9}'), chars.next()); assert_eq!(None, chars.next()); let mut chars = "é".chars(); // U+0065: 'latin small letter e' assert_eq!(Some('\u{0065}'), chars.next()); // U+0301: 'combining acute accent' assert_eq!(Some('\u{0301}'), chars.next()); assert_eq!(None, chars.next());Run
This means that the contents of the first string above will fit into a
char
while the contents of the second string will not. Trying to create
a char
literal with the contents of the second string gives an error:
error: character literal may only contain one codepoint: 'é'
let c = 'é';
^^^
Another implication of the 4-byte fixed size of a char
is that
per-char
processing can end up using a lot more memory:
let s = String::from("love: ❤️"); let v: Vec<char> = s.chars().collect(); assert_eq!(12, std::mem::size_of_val(&s[..])); assert_eq!(32, std::mem::size_of_val(&v[..]));Run
Methods
impl char
[src]
pub fn is_digit(self, radix: u32) -> bool
[src]
Checks if a char
is a digit in the given radix.
A 'radix' here is sometimes also called a 'base'. A radix of two indicates a binary number, a radix of ten, decimal, and a radix of sixteen, hexadecimal, to give some common values. Arbitrary radices are supported.
Compared to is_numeric()
, this function only recognizes the characters
0-9
, a-z
and A-Z
.
'Digit' is defined to be only the following characters:
0-9
a-z
A-Z
For a more comprehensive understanding of 'digit', see is_numeric
.
Panics
Panics if given a radix larger than 36.
Examples
Basic usage:
assert!('1'.is_digit(10)); assert!('f'.is_digit(16)); assert!(!'f'.is_digit(10));Run
Passing a large radix, causing a panic:
use std::thread; let result = thread::spawn(|| { // this panics '1'.is_digit(37); }).join(); assert!(result.is_err());Run
pub fn to_digit(self, radix: u32) -> Option<u32>
[src]
Converts a char
to a digit in the given radix.
A 'radix' here is sometimes also called a 'base'. A radix of two indicates a binary number, a radix of ten, decimal, and a radix of sixteen, hexadecimal, to give some common values. Arbitrary radices are supported.
'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.
Examples
Basic usage:
assert_eq!('1'.to_digit(10), Some(1)); assert_eq!('f'.to_digit(16), Some(15));Run
Passing a non-digit results in failure:
assert_eq!('f'.to_digit(10), None); assert_eq!('z'.to_digit(16), None);Run
Passing a large radix, causing a panic:
use std::thread; let result = thread::spawn(|| { '1'.to_digit(37); }).join(); assert!(result.is_err());Run
ⓘImportant traits for EscapeUnicodepub fn escape_unicode(self) -> EscapeUnicode
[src]
Returns an iterator that yields the hexadecimal Unicode escape of a
character as char
s.
This will escape characters with the Rust syntax of the form
\u{NNNNNN}
where NNNNNN
is a hexadecimal representation.
Examples
As an iterator:
for c in '❤'.escape_unicode() { print!("{}", c); } println!();Run
Using println!
directly:
println!("{}", '❤'.escape_unicode());Run
Both are equivalent to:
println!("\\u{{2764}}");Run
Using to_string
:
assert_eq!('❤'.escape_unicode().to_string(), "\\u{2764}");Run
ⓘImportant traits for EscapeDebugpub fn escape_debug(self) -> EscapeDebug
1.20.0[src]
Returns an iterator that yields the literal escape code of a character
as char
s.
This will escape the characters similar to the Debug
implementations
of str
or char
.
Examples
As an iterator:
for c in '\n'.escape_debug() { print!("{}", c); } println!();Run
Using println!
directly:
println!("{}", '\n'.escape_debug());Run
Both are equivalent to:
println!("\\n");Run
Using to_string
:
assert_eq!('\n'.escape_debug().to_string(), "\\n");Run
ⓘImportant traits for EscapeDefaultpub fn escape_default(self) -> EscapeDefault
[src]
Returns an iterator that yields the literal escape code of a character
as char
s.
The default is chosen with a bias toward producing literals that are legal in a variety of languages, including C++11 and similar C-family languages. The exact rules are:
- Tab is escaped as
\t
. - Carriage return is escaped as
\r
. - Line feed is escaped as
\n
. - Single quote is escaped as
'
. - Double quote is escaped as
"
. - Backslash is escaped as
\
. - Any character in the 'printable ASCII' range
0x20
..0x7e
inclusive is not escaped. - All other characters are given hexadecimal Unicode escapes; see
escape_unicode
.
Examples
As an iterator:
for c in '"'.escape_default() { print!("{}", c); } println!();Run
Using println!
directly:
println!("{}", '"'.escape_default());Run
Both are equivalent to:
println!("\\\"");Run
Using to_string
:
assert_eq!('"'.escape_default().to_string(), "\\\"");Run
pub fn len_utf8(self) -> usize
[src]
Returns the number of bytes this char
would need if encoded in UTF-8.
That number of bytes is always between 1 and 4, inclusive.
Examples
Basic usage:
let len = 'A'.len_utf8(); assert_eq!(len, 1); let len = 'ß'.len_utf8(); assert_eq!(len, 2); let len = 'ℝ'.len_utf8(); assert_eq!(len, 3); let len = '💣'.len_utf8(); assert_eq!(len, 4);Run
The &str
type guarantees that its contents are UTF-8, and so we can compare the length it
would take if each code point was represented as a char
vs in the &str
itself:
// as chars let eastern = '東'; let capitol = '京'; // both can be represented as three bytes assert_eq!(3, eastern.len_utf8()); assert_eq!(3, capitol.len_utf8()); // as a &str, these two are encoded in UTF-8 let tokyo = "東京"; let len = eastern.len_utf8() + capitol.len_utf8(); // we can see that they take six bytes total... assert_eq!(6, tokyo.len()); // ... just like the &str assert_eq!(len, tokyo.len());Run
pub fn len_utf16(self) -> usize
[src]
Returns the number of 16-bit code units this char
would need if
encoded in UTF-16.
See the documentation for len_utf8
for more explanation of this
concept. This function is a mirror, but for UTF-16 instead of UTF-8.
Examples
Basic usage:
let n = 'ß'.len_utf16(); assert_eq!(n, 1); let len = '💣'.len_utf16(); assert_eq!(len, 2);Run
pub fn encode_utf8(self, dst: &mut [u8]) -> &mut str
1.15.0[src]
Encodes this character as UTF-8 into the provided byte buffer, and then returns the subslice of the buffer that contains the encoded character.
Panics
Panics if the buffer is not large enough.
A buffer of length four is large enough to encode any char
.
Examples
In both of these examples, 'ß' takes two bytes to encode.
let mut b = [0; 2]; let result = 'ß'.encode_utf8(&mut b); assert_eq!(result, "ß"); assert_eq!(result.len(), 2);Run
A buffer that's too small:
use std::thread; let result = thread::spawn(|| { let mut b = [0; 1]; // this panics 'ß'.encode_utf8(&mut b); }).join(); assert!(result.is_err());Run
pub fn encode_utf16(self, dst: &mut [u16]) -> &mut [u16]
1.15.0[src]
Encodes this character as UTF-16 into the provided u16
buffer,
and then returns the subslice of the buffer that contains the encoded character.
Panics
Panics if the buffer is not large enough.
A buffer of length 2 is large enough to encode any char
.
Examples
In both of these examples, '𝕊' takes two u16
s to encode.
let mut b = [0; 2]; let result = '𝕊'.encode_utf16(&mut b); assert_eq!(result.len(), 2);Run
A buffer that's too small:
use std::thread; let result = thread::spawn(|| { let mut b = [0; 1]; // this panics '𝕊'.encode_utf16(&mut b); }).join(); assert!(result.is_err());Run
pub fn is_alphabetic(self) -> bool
[src]
Returns true
if this char
is an alphabetic code point, and false if not.
Examples
Basic usage:
assert!('a'.is_alphabetic()); assert!('京'.is_alphabetic()); let c = '💝'; // love is many things, but it is not alphabetic assert!(!c.is_alphabetic());Run
pub fn is_xid_start(self) -> bool
[src]
⚙️ This is an internal compiler API. (rustc_private
#27812)
This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml
.
Returns true
if this char
satisfies the 'XID_Start' Unicode property, and false
otherwise.
'XID_Start' is a Unicode Derived Property specified in
UAX #31,
mostly similar to ID_Start
but modified for closure under NFKx
.
pub fn is_xid_continue(self) -> bool
[src]
⚙️ This is an internal compiler API. (rustc_private
#27812)
This crate is being loaded from the sysroot, a permanently unstable location for private compiler dependencies. It is not intended for general use. Prefer using a public version of this crate from crates.io via Cargo.toml
.
Returns true
if this char
satisfies the 'XID_Continue' Unicode property, and false
otherwise.
'XID_Continue' is a Unicode Derived Property specified in UAX #31, mostly similar to 'ID_Continue' but modified for closure under NFKx.
pub fn is_lowercase(self) -> bool
[src]
Returns true
if this char
is lowercase.
'Lowercase' is defined according to the terms of the Unicode Derived Core
Property Lowercase
.
Examples
Basic usage:
assert!('a'.is_lowercase()); assert!('δ'.is_lowercase()); assert!(!'A'.is_lowercase()); assert!(!'Δ'.is_lowercase()); // The various Chinese scripts do not have case, and so: assert!(!'中'.is_lowercase());Run
pub fn is_uppercase(self) -> bool
[src]
Returns true
if this char
is uppercase.
'Uppercase' is defined according to the terms of the Unicode Derived Core
Property Uppercase
.
Examples
Basic usage:
assert!(!'a'.is_uppercase()); assert!(!'δ'.is_uppercase()); assert!('A'.is_uppercase()); assert!('Δ'.is_uppercase()); // The various Chinese scripts do not have case, and so: assert!(!'中'.is_uppercase());Run
pub fn is_whitespace(self) -> bool
[src]
Returns true
if this char
is whitespace.
'Whitespace' is defined according to the terms of the Unicode Derived Core
Property White_Space
.
Examples
Basic usage:
assert!(' '.is_whitespace()); // a non-breaking space assert!('\u{A0}'.is_whitespace()); assert!(!'越'.is_whitespace());Run
pub fn is_alphanumeric(self) -> bool
[src]
Returns true
if this char
is alphanumeric.
'Alphanumeric'-ness is defined in terms of the Unicode General Categories 'Nd', 'Nl', 'No' and the Derived Core Property 'Alphabetic'.
Examples
Basic usage:
assert!('٣'.is_alphanumeric()); assert!('7'.is_alphanumeric()); assert!('৬'.is_alphanumeric()); assert!('¾'.is_alphanumeric()); assert!('①'.is_alphanumeric()); assert!('K'.is_alphanumeric()); assert!('و'.is_alphanumeric()); assert!('藏'.is_alphanumeric());Run
pub fn is_control(self) -> bool
[src]
Returns true
if this char
is a control code point.
'Control code point' is defined in terms of the Unicode General
Category Cc
.
Examples
Basic usage:
// U+009C, STRING TERMINATOR assert!(''.is_control()); assert!(!'q'.is_control());Run
pub fn is_numeric(self) -> bool
[src]
Returns true
if this char
is numeric.
'Numeric'-ness is defined in terms of the Unicode General Categories 'Nd', 'Nl', 'No'.
Examples
Basic usage:
assert!('٣'.is_numeric()); assert!('7'.is_numeric()); assert!('৬'.is_numeric()); assert!('¾'.is_numeric()); assert!('①'.is_numeric()); assert!(!'K'.is_numeric()); assert!(!'و'.is_numeric()); assert!(!'藏'.is_numeric());Run
ⓘImportant traits for ToLowercasepub fn to_lowercase(self) -> ToLowercase
[src]
Returns an iterator that yields the lowercase equivalent of a char
as one or more char
s.
If a character does not have a lowercase equivalent, the same character will be returned back by the iterator.
This performs complex unconditional mappings with no tailoring: it maps
one Unicode character to its lowercase equivalent according to the
Unicode database and the additional complex mappings
SpecialCasing.txt
. Conditional mappings (based on context or
language) are not considered here.
For a full reference, see here.
Examples
As an iterator:
for c in 'İ'.to_lowercase() { print!("{}", c); } println!();Run
Using println!
directly:
println!("{}", 'İ'.to_lowercase());Run
Both are equivalent to:
println!("i\u{307}");Run
Using to_string
:
assert_eq!('C'.to_lowercase().to_string(), "c"); // Sometimes the result is more than one character: assert_eq!('İ'.to_lowercase().to_string(), "i\u{307}"); // Characters that do not have both uppercase and lowercase // convert into themselves. assert_eq!('山'.to_lowercase().to_string(), "山");Run
ⓘImportant traits for ToUppercasepub fn to_uppercase(self) -> ToUppercase
[src]
Returns an iterator that yields the uppercase equivalent of a char
as one or more char
s.
If a character does not have an uppercase equivalent, the same character will be returned back by the iterator.
This performs complex unconditional mappings with no tailoring: it maps
one Unicode character to its uppercase equivalent according to the
Unicode database and the additional complex mappings
SpecialCasing.txt
. Conditional mappings (based on context or
language) are not considered here.
For a full reference, see here.
Examples
As an iterator:
for c in 'ß'.to_uppercase() { print!("{}", c); } println!();Run
Using println!
directly:
println!("{}", 'ß'.to_uppercase());Run
Both are equivalent to:
println!("SS");Run
Using to_string
:
assert_eq!('c'.to_uppercase().to_string(), "C"); // Sometimes the result is more than one character: assert_eq!('ß'.to_uppercase().to_string(), "SS"); // Characters that do not have both uppercase and lowercase // convert into themselves. assert_eq!('山'.to_uppercase().to_string(), "山");Run
Note on locale
In Turkish, the equivalent of 'i' in Latin has five forms instead of two:
- 'Dotless': I / ı, sometimes written ï
- 'Dotted': İ / i
Note that the lowercase dotted 'i' is the same as the Latin. Therefore:
let upper_i = 'i'.to_uppercase().to_string();Run
The value of upper_i
here relies on the language of the text: if we're
in en-US
, it should be "I"
, but if we're in tr_TR
, it should
be "İ"
. to_uppercase()
does not take this into account, and so:
let upper_i = 'i'.to_uppercase().to_string(); assert_eq!(upper_i, "I");Run
holds across languages.
pub const fn is_ascii(&self) -> bool
1.23.0[src]
Checks if the value is within the ASCII range.
Examples
let ascii = 'a'; let non_ascii = '❤'; assert!(ascii.is_ascii()); assert!(!non_ascii.is_ascii());Run
pub fn to_ascii_uppercase(&self) -> char
1.23.0[src]
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.
To uppercase the value in-place, use make_ascii_uppercase
.
To uppercase ASCII characters in addition to non-ASCII characters, use
to_uppercase
.
Examples
let ascii = 'a'; let non_ascii = '❤'; assert_eq!('A', ascii.to_ascii_uppercase()); assert_eq!('❤', non_ascii.to_ascii_uppercase());Run
pub fn to_ascii_lowercase(&self) -> char
1.23.0[src]
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.
To lowercase the value in-place, use make_ascii_lowercase
.
To lowercase ASCII characters in addition to non-ASCII characters, use
to_lowercase
.
Examples
let ascii = 'A'; let non_ascii = '❤'; assert_eq!('a', ascii.to_ascii_lowercase()); assert_eq!('❤', non_ascii.to_ascii_lowercase());Run
pub fn eq_ignore_ascii_case(&self, other: &char) -> bool
1.23.0[src]
Checks that two values are an ASCII case-insensitive match.
Equivalent to to_ascii_lowercase(a) == to_ascii_lowercase(b)
.
Examples
let upper_a = 'A'; let lower_a = 'a'; let lower_z = 'z'; assert!(upper_a.eq_ignore_ascii_case(&lower_a)); assert!(upper_a.eq_ignore_ascii_case(&upper_a)); assert!(!upper_a.eq_ignore_ascii_case(&lower_z));Run
pub fn make_ascii_uppercase(&mut self)
1.23.0[src]
Converts this type 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.
To return a new uppercased value without modifying the existing one, use
to_ascii_uppercase
.
Examples
let mut ascii = 'a'; ascii.make_ascii_uppercase(); assert_eq!('A', ascii);Run
pub fn make_ascii_lowercase(&mut self)
1.23.0[src]
Converts this type 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.
To return a new lowercased value without modifying the existing one, use
to_ascii_lowercase
.
Examples
let mut ascii = 'A'; ascii.make_ascii_lowercase(); assert_eq!('a', ascii);Run
pub fn is_ascii_alphabetic(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII alphabetic character:
- U+0041 'A' ... U+005A 'Z', or
- U+0061 'a' ... U+007A 'z'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(uppercase_a.is_ascii_alphabetic()); assert!(uppercase_g.is_ascii_alphabetic()); assert!(a.is_ascii_alphabetic()); assert!(g.is_ascii_alphabetic()); assert!(!zero.is_ascii_alphabetic()); assert!(!percent.is_ascii_alphabetic()); assert!(!space.is_ascii_alphabetic()); assert!(!lf.is_ascii_alphabetic()); assert!(!esc.is_ascii_alphabetic());Run
pub fn is_ascii_uppercase(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII uppercase character: U+0041 'A' ... U+005A 'Z'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(uppercase_a.is_ascii_uppercase()); assert!(uppercase_g.is_ascii_uppercase()); assert!(!a.is_ascii_uppercase()); assert!(!g.is_ascii_uppercase()); assert!(!zero.is_ascii_uppercase()); assert!(!percent.is_ascii_uppercase()); assert!(!space.is_ascii_uppercase()); assert!(!lf.is_ascii_uppercase()); assert!(!esc.is_ascii_uppercase());Run
pub fn is_ascii_lowercase(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII lowercase character: U+0061 'a' ... U+007A 'z'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(!uppercase_a.is_ascii_lowercase()); assert!(!uppercase_g.is_ascii_lowercase()); assert!(a.is_ascii_lowercase()); assert!(g.is_ascii_lowercase()); assert!(!zero.is_ascii_lowercase()); assert!(!percent.is_ascii_lowercase()); assert!(!space.is_ascii_lowercase()); assert!(!lf.is_ascii_lowercase()); assert!(!esc.is_ascii_lowercase());Run
pub fn is_ascii_alphanumeric(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII alphanumeric character:
- U+0041 'A' ... U+005A 'Z', or
- U+0061 'a' ... U+007A 'z', or
- U+0030 '0' ... U+0039 '9'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(uppercase_a.is_ascii_alphanumeric()); assert!(uppercase_g.is_ascii_alphanumeric()); assert!(a.is_ascii_alphanumeric()); assert!(g.is_ascii_alphanumeric()); assert!(zero.is_ascii_alphanumeric()); assert!(!percent.is_ascii_alphanumeric()); assert!(!space.is_ascii_alphanumeric()); assert!(!lf.is_ascii_alphanumeric()); assert!(!esc.is_ascii_alphanumeric());Run
pub fn is_ascii_digit(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII decimal digit: U+0030 '0' ... U+0039 '9'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(!uppercase_a.is_ascii_digit()); assert!(!uppercase_g.is_ascii_digit()); assert!(!a.is_ascii_digit()); assert!(!g.is_ascii_digit()); assert!(zero.is_ascii_digit()); assert!(!percent.is_ascii_digit()); assert!(!space.is_ascii_digit()); assert!(!lf.is_ascii_digit()); assert!(!esc.is_ascii_digit());Run
pub fn is_ascii_hexdigit(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII hexadecimal digit:
- U+0030 '0' ... U+0039 '9', or
- U+0041 'A' ... U+0046 'F', or
- U+0061 'a' ... U+0066 'f'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(uppercase_a.is_ascii_hexdigit()); assert!(!uppercase_g.is_ascii_hexdigit()); assert!(a.is_ascii_hexdigit()); assert!(!g.is_ascii_hexdigit()); assert!(zero.is_ascii_hexdigit()); assert!(!percent.is_ascii_hexdigit()); assert!(!space.is_ascii_hexdigit()); assert!(!lf.is_ascii_hexdigit()); assert!(!esc.is_ascii_hexdigit());Run
pub fn is_ascii_punctuation(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII punctuation character:
- U+0021 ... U+002F
! " # $ % & ' ( ) * + , - . /
, or - U+003A ... U+0040
: ; < = > ? @
, or - U+005B ... U+0060
[ \ ] ^ _ `
, or - U+007B ... U+007E
{ | } ~
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(!uppercase_a.is_ascii_punctuation()); assert!(!uppercase_g.is_ascii_punctuation()); assert!(!a.is_ascii_punctuation()); assert!(!g.is_ascii_punctuation()); assert!(!zero.is_ascii_punctuation()); assert!(percent.is_ascii_punctuation()); assert!(!space.is_ascii_punctuation()); assert!(!lf.is_ascii_punctuation()); assert!(!esc.is_ascii_punctuation());Run
pub fn is_ascii_graphic(&self) -> bool
1.24.0[src]
Checks if the value is an ASCII graphic character: U+0021 '!' ... U+007E '~'.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(uppercase_a.is_ascii_graphic()); assert!(uppercase_g.is_ascii_graphic()); assert!(a.is_ascii_graphic()); assert!(g.is_ascii_graphic()); assert!(zero.is_ascii_graphic()); assert!(percent.is_ascii_graphic()); assert!(!space.is_ascii_graphic()); assert!(!lf.is_ascii_graphic()); assert!(!esc.is_ascii_graphic());Run
pub fn is_ascii_whitespace(&self) -> bool
1.24.0[src]
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.
Rust uses the WhatWG Infra Standard's definition of ASCII whitespace. There are several other definitions in wide use. For instance, the POSIX locale includes U+000B VERTICAL TAB as well as all the above characters, but—from the very same specification—the default rule for "field splitting" in the Bourne shell considers only SPACE, HORIZONTAL TAB, and LINE FEED as whitespace.
If you are writing a program that will process an existing file format, check what that format's definition of whitespace is before using this function.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(!uppercase_a.is_ascii_whitespace()); assert!(!uppercase_g.is_ascii_whitespace()); assert!(!a.is_ascii_whitespace()); assert!(!g.is_ascii_whitespace()); assert!(!zero.is_ascii_whitespace()); assert!(!percent.is_ascii_whitespace()); assert!(space.is_ascii_whitespace()); assert!(lf.is_ascii_whitespace()); assert!(!esc.is_ascii_whitespace());Run
pub fn is_ascii_control(&self) -> bool
1.24.0[src]
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.
Examples
let uppercase_a = 'A'; let uppercase_g = 'G'; let a = 'a'; let g = 'g'; let zero = '0'; let percent = '%'; let space = ' '; let lf = '\n'; let esc: char = 0x1b_u8.into(); assert!(!uppercase_a.is_ascii_control()); assert!(!uppercase_g.is_ascii_control()); assert!(!a.is_ascii_control()); assert!(!g.is_ascii_control()); assert!(!zero.is_ascii_control()); assert!(!percent.is_ascii_control()); assert!(!space.is_ascii_control()); assert!(lf.is_ascii_control()); assert!(esc.is_ascii_control());Run
Trait Implementations
impl From<u8> for char
1.13.0[src]
Maps a byte in 0x00...0xFF to a char
whose code point has the same value, in U+0000 to U+00FF.
Unicode is designed such that this effectively decodes bytes with the character encoding that IANA calls ISO-8859-1. This encoding is compatible with ASCII.
Note that this is different from ISO/IEC 8859-1 a.k.a. ISO 8859-1 (with one less hyphen), which leaves some "blanks", byte values that are not assigned to any character. ISO-8859-1 (the IANA one) assigns them to the C0 and C1 control codes.
Note that this is also different from Windows-1252 a.k.a. code page 1252, which is a superset ISO/IEC 8859-1 that assigns some (not all!) blanks to punctuation and various Latin characters.
To confuse things further, on the Web
ascii
, iso-8859-1
, and windows-1252
are all aliases
for a superset of Windows-1252 that fills the remaining blanks with corresponding
C0 and C1 control codes.
impl TryFrom<u32> for char
1.34.0[src]
type Error = CharTryFromError
The type returned in the event of a conversion error.
fn try_from(i: u32) -> Result<char, <char as TryFrom<u32>>::Error>
[src]
impl PartialOrd<char> for char
[src]
fn partial_cmp(&self, other: &char) -> Option<Ordering>
[src]
fn lt(&self, other: &char) -> bool
[src]
fn le(&self, other: &char) -> bool
[src]
fn ge(&self, other: &char) -> bool
[src]
fn gt(&self, other: &char) -> bool
[src]
impl Hash for char
[src]
fn hash<H>(&self, state: &mut H) where
H: Hasher,
[src]
H: Hasher,
fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,
1.3.0[src]
H: Hasher,
Feeds a slice of this type into the given [Hasher
]. Read more
impl Default for char
[src]
impl Eq for char
[src]
impl Clone for char
[src]
fn clone(&self) -> char
[src]
fn clone_from(&mut self, source: &Self)
[src]
Performs copy-assignment from source
. Read more
impl Debug for char
[src]
impl<'a> Pattern<'a> for char
[src]
Searches for chars that are equal to a given char
type Searcher = CharSearcher<'a>
🔬 This is a nightly-only experimental API. (pattern
#27721)
API not fully fleshed out and ready to be stabilized
Associated searcher for this pattern
fn into_searcher(self, haystack: &'a str) -> <char as Pattern<'a>>::Searcher
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool where
<char as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
[src]
<char as Pattern<'a>>::Searcher: ReverseSearcher<'a>,
impl Copy for char
[src]
impl Ord for char
[src]
fn cmp(&self, other: &char) -> Ordering
[src]
fn max(self, other: Self) -> Self
1.21.0[src]
Compares and returns the maximum of two values. Read more
fn min(self, other: Self) -> Self
1.21.0[src]
Compares and returns the minimum of two values. Read more
fn clamp(self, min: Self, max: Self) -> Self
[src]
Restrict a value to a certain interval. Read more
impl PartialEq<char> for char
[src]
impl Display for char
[src]
impl FromStr for char
1.20.0[src]
type Err = ParseCharError
The associated error which can be returned from parsing.
fn from_str(s: &str) -> Result<char, <char as FromStr>::Err>
[src]
impl AsciiExt for char
[src]
type Owned = char
use inherent methods instead
Container type for copied ASCII characters.
fn is_ascii(&self) -> bool
[src]
fn to_ascii_uppercase(&self) -> Self::Owned
[src]
fn to_ascii_lowercase(&self) -> Self::Owned
[src]
fn eq_ignore_ascii_case(&self, o: &Self) -> bool
[src]
fn make_ascii_uppercase(&mut self)
[src]
fn make_ascii_lowercase(&mut self)
[src]
Auto Trait Implementations
Blanket Implementations
impl<'a, F> Pattern<'a> for F where
F: FnMut(char) -> bool,
[src]
F: FnMut(char) -> bool,
type Searcher = CharPredicateSearcher<'a, F>
🔬 This is a nightly-only experimental API. (pattern
#27721)
API not fully fleshed out and ready to be stabilized
Associated searcher for this pattern
fn into_searcher(self, haystack: &'a str) -> CharPredicateSearcher<'a, F>
[src]
fn is_contained_in(self, haystack: &'a str) -> bool
[src]
fn is_prefix_of(self, haystack: &'a str) -> bool
[src]
fn is_suffix_of(self, haystack: &'a str) -> bool where
CharPredicateSearcher<'a, F>: ReverseSearcher<'a>,
[src]
CharPredicateSearcher<'a, F>: ReverseSearcher<'a>,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
[src]
U: Into<T>,
type Error = Infallible
The type returned in the event of a conversion error.
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
[src]
impl<T, U> Into<U> for T where
U: From<T>,
[src]
U: From<T>,
impl<T> From<T> for T
[src]
impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
[src]
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
[src]
impl<T> Borrow<T> for T where
T: ?Sized,
[src]
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
[src]
T: ?Sized,
ⓘImportant traits for &'_ mut Ffn borrow_mut(&mut self) -> &mut T
[src]
impl<T> Any for T where
T: 'static + ?Sized,
[src]
T: 'static + ?Sized,
impl<T> ToOwned for T where
T: Clone,
[src]
T: Clone,
type Owned = T
The resulting type after obtaining ownership.
fn to_owned(&self) -> T
[src]
fn clone_into(&self, target: &mut T)
[src]
impl<T> ToString for T where
T: Display + ?Sized,
[src]
T: Display + ?Sized,