Enum mime::TopLevel
[−]
[src]
pub enum TopLevel { Star, Text, Image, Audio, Video, Application, Multipart, Message, Model, Ext(String), }
Variants
Star | |
Text | |
Image | |
Audio | |
Video | |
Application | |
Multipart | |
Message | |
Model | |
Ext |
Methods
impl TopLevel
Methods from Deref<Target=str>
fn len(&self) -> usize
Returns the length of self
in bytes.
Examples
assert_eq!("foo".len(), 3); assert_eq!("ƒoo".len(), 4); // fancy f!
fn is_empty(&self) -> bool
fn is_char_boundary(&self, index: usize) -> bool
str_char
): it is unclear whether this method pulls its weight with the existence of the char_indices iterator or this method may want to be replaced with checked slicing
Checks that index
-th byte lies at the start and/or end of a
UTF-8 code point sequence.
The start and end of the string (when index == self.len()
) are
considered to be
boundaries.
Returns false
if index
is greater than self.len()
.
Examples
#![feature(str_char)] let s = "Löwe 老虎 Léopard"; assert!(s.is_char_boundary(0)); // start of `老` assert!(s.is_char_boundary(6)); assert!(s.is_char_boundary(s.len())); // second byte of `ö` assert!(!s.is_char_boundary(2)); // third byte of `老` assert!(!s.is_char_boundary(8));
fn as_bytes(&self) -> &[u8]
fn as_ptr(&self) -> *const u8
Returns a raw pointer to the &str
's buffer.
The caller must ensure that the string outlives this pointer, and that it is not reallocated (e.g. by pushing to the string).
Examples
let s = "Hello"; let p = s.as_ptr();
unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str
Takes a bytewise slice from a string.
Returns the substring from [begin
..end
).
Safety
Caller must check both UTF-8 sequence boundaries and the boundaries of the entire slice as well.
Examples
let s = "Löwe 老虎 Léopard"; unsafe { assert_eq!(s.slice_unchecked(0, 21), "Löwe 老虎 Léopard"); }
unsafe fn slice_mut_unchecked(&mut self, begin: usize, end: usize) -> &mut str
str_slice_mut
): recently added
Takes a bytewise mutable slice from a string.
Same as slice_unchecked
, but works with &mut str
instead of &str
.
fn char_range_at(&self, start: usize) -> CharRange
str_char
): often replaced by char_indices, this method may be removed in favor of just char_at() or eventually removed altogether
Given a byte position, return the next code point and its index.
This can be used to iterate over the Unicode code points of a string.
Panics
If i
is greater than or equal to the length of the string.
If i
is not the index of the beginning of a valid UTF-8 sequence.
Examples
This example manually iterates through the code points of a string;
this should normally be
done by .chars()
or .char_indices()
.
#![feature(str_char, core)] use std::str::CharRange; let s = "中华Việt Nam"; let mut i = 0; while i < s.len() { let CharRange {ch, next} = s.char_range_at(i); println!("{}: {}", i, ch); i = next; }
This outputs:
0: 中
3: 华
6: V
7: i
8: e
9:
11:
13: t
14:
15: N
16: a
17: m
fn char_range_at_reverse(&self, start: usize) -> CharRange
str_char
): often replaced by char_indices, this method may be removed in favor of just char_at_reverse() or eventually removed altogether
Given a byte position, return the previous char
and its position.
This function can be used to iterate over a Unicode code points in reverse.
Note that Unicode has many features, such as combining marks, ligatures, and direction marks, that need to be taken into account to correctly reverse a string.
Returns 0 for next index if called on start index 0.
Panics
If i
is greater than the length of the string.
If i
is not an index following a valid UTF-8 sequence.
Examples
This example manually iterates through the code points of a string;
this should normally be
done by .chars().rev()
or .char_indices()
.
#![feature(str_char, core)] use std::str::CharRange; let s = "中华Việt Nam"; let mut i = s.len(); while i > 0 { let CharRange {ch, next} = s.char_range_at_reverse(i); println!("{}: {}", i, ch); i = next; }
This outputs:
18: m
17: a
16: N
15:
14: t
13:
11:
9: e
8: i
7: V
6: 华
3: 中
fn char_at(&self, i: usize) -> char
str_char
): frequently replaced by the chars() iterator, this method may be removed or possibly renamed in the future; it is normally replaced by chars/char_indices iterators or by getting the first char from a subslice
Given a byte position, return the char
at that position.
Panics
If i
is greater than or equal to the length of the string.
If i
is not the index of the beginning of a valid UTF-8 sequence.
Examples
#![feature(str_char)] let s = "abπc"; assert_eq!(s.char_at(1), 'b'); assert_eq!(s.char_at(2), 'π'); assert_eq!(s.char_at(4), 'c');
fn char_at_reverse(&self, i: usize) -> char
str_char
): see char_at for more details, but reverse semantics are also somewhat unclear, especially with which cases generate panics
Given a byte position, return the char
at that position, counting
from the end.
Panics
If i
is greater than the length of the string.
If i
is not an index following a valid UTF-8 sequence.
Examples
#![feature(str_char)] let s = "abπc"; assert_eq!(s.char_at_reverse(1), 'a'); assert_eq!(s.char_at_reverse(2), 'b'); assert_eq!(s.char_at_reverse(3), 'π');
fn slice_shift_char(&self) -> Option<(char, &str)>
str_char
): awaiting conventions about shifting and slices and may not be warranted with the existence of the chars and/or char_indices iterators
Retrieves the first code point from a &str
and returns it.
Note that a single Unicode character (grapheme cluster)
can be composed of multiple char
s.
This does not allocate a new string; instead, it returns a slice that points one code point beyond the code point that was shifted.
None
is returned if the slice is empty.
Examples
#![feature(str_char)] let s = "Łódź"; // \u{141}o\u{301}dz\u{301} let (c, s1) = s.slice_shift_char().unwrap(); assert_eq!(c, 'Ł'); assert_eq!(s1, "ódź"); let (c, s2) = s1.slice_shift_char().unwrap(); assert_eq!(c, 'o'); assert_eq!(s2, "\u{301}dz\u{301}");
fn split_at(&self, mid: usize) -> (&str, &str)
Divide one string slice into two at an index.
The index mid
is a byte offset from the start of the string
that must be on a char
boundary.
Return slices &self[..mid]
and &self[mid..]
.
Panics
Panics if mid
is beyond the last code point of the string,
or if it is not on a char
boundary.
Examples
let s = "Löwe 老虎 Léopard"; let first_space = s.find(' ').unwrap_or(s.len()); let (a, b) = s.split_at(first_space); assert_eq!(a, "Löwe"); assert_eq!(b, " 老虎 Léopard");
fn split_at_mut(&mut self, mid: usize) -> (&mut str, &mut str)
Divide one mutable string slice into two at an index.
fn chars(&self) -> Chars
An iterator over the code points of self
.
In Unicode relationship between code points and characters is complex. A single character may be composed of multiple code points (e.g. diacritical marks added to a letter), and a single code point (e.g. Hangul syllable) may contain multiple characters.
For iteration over human-readable characters a grapheme cluster iterator may be more appropriate. See the unicode-segmentation crate.
Examples
let v: Vec<char> = "ASCII żółć 🇨🇭 한".chars().collect(); assert_eq!(v, ['A', 'S', 'C', 'I', 'I', ' ', 'z', '\u{307}', 'o', '\u{301}', 'ł', 'c', '\u{301}', ' ', '\u{1f1e8}', '\u{1f1ed}', ' ', '한']);
fn char_indices(&self) -> CharIndices
An iterator over the char
s of self
and their byte offsets.
Examples
let v: Vec<(usize, char)> = "A🇨🇭".char_indices().collect(); let b = vec![(0, 'A'), (1, '\u{1f1e8}'), (5, '\u{1f1ed}')]; assert_eq!(v, b);
fn bytes(&self) -> Bytes
An iterator over the bytes of self
.
Examples
let v: Vec<u8> = "bors".bytes().collect(); assert_eq!(v, b"bors".to_vec());
fn split_whitespace(&self) -> SplitWhitespace
An iterator over the non-empty substrings of self
which contain no whitespace,
and which are separated by any amount of whitespace.
Examples
let some_words = " Mary had\ta\u{2009}little \n\t lamb"; let v: Vec<&str> = some_words.split_whitespace().collect(); assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]);
fn lines(&self) -> Lines
An iterator over the lines of a string, separated by \n
or \r\n
.
This does not include the empty string after a trailing newline or CRLF.
Examples
let four_lines = "foo\nbar\n\r\nbaz"; let v: Vec<&str> = four_lines.lines().collect(); assert_eq!(v, ["foo", "bar", "", "baz"]);
Leaving off the trailing character:
let four_lines = "foo\r\nbar\n\nbaz\n"; let v: Vec<&str> = four_lines.lines().collect(); assert_eq!(v, ["foo", "bar", "", "baz"]);
fn lines_any(&self) -> LinesAny
: use lines() instead now
An iterator over the lines of a string, separated by either
\n
or \r\n
.
As with .lines()
, this does not include an empty trailing line.
Examples
let four_lines = "foo\r\nbar\n\r\nbaz"; let v: Vec<&str> = four_lines.lines_any().collect(); assert_eq!(v, ["foo", "bar", "", "baz"]);
Leaving off the trailing character:
let four_lines = "foo\r\nbar\n\r\nbaz\n"; let v: Vec<&str> = four_lines.lines_any().collect(); assert_eq!(v, ["foo", "bar", "", "baz"]);
fn utf16_units(&self) -> Utf16Units
str_utf16
): this functionality may only be provided by libunicode
Returns an iterator of u16
over the string encoded as UTF-16.
fn contains<'a, P>(&'a self, pat: P) -> bool where P: Pattern<'a>
Returns true
if self
contains another &str
.
Examples
assert!("bananas".contains("nana")); assert!(!"bananas".contains("foobar"));
fn starts_with<'a, P>(&'a self, pat: P) -> bool where P: Pattern<'a>
Returns true
if the given &str
is a prefix of the string.
Examples
assert!("banana".starts_with("ba"));
fn ends_with<'a, P>(&'a self, pat: P) -> bool where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
Returns true if the given &str
is a suffix of the string.
Examples
assert!("banana".ends_with("nana"));
fn find<'a, P>(&'a self, pat: P) -> Option<usize> where P: Pattern<'a>
Returns the byte index of the first character of self
that matches
the pattern, if it
exists.
Returns None
if it doesn't exist.
The pattern can be a simple &str
, char
, or a closure that
determines if a character matches.
Examples
Simple patterns:
let s = "Löwe 老虎 Léopard"; assert_eq!(s.find('L'), Some(0)); assert_eq!(s.find('é'), Some(14)); assert_eq!(s.find("Léopard"), Some(13));
More complex patterns with closures:
let s = "Löwe 老虎 Léopard"; assert_eq!(s.find(char::is_whitespace), Some(5)); assert_eq!(s.find(char::is_lowercase), Some(1));
Not finding the pattern:
let s = "Löwe 老虎 Léopard"; let x: &[_] = &['1', '2']; assert_eq!(s.find(x), None);
fn rfind<'a, P>(&'a self, pat: P) -> Option<usize> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
Returns the byte index of the last character of self
that
matches the pattern, if it
exists.
Returns None
if it doesn't exist.
The pattern can be a simple &str
, char
,
or a closure that determines if a character matches.
Examples
Simple patterns:
let s = "Löwe 老虎 Léopard"; assert_eq!(s.rfind('L'), Some(13)); assert_eq!(s.rfind('é'), Some(14));
More complex patterns with closures:
let s = "Löwe 老虎 Léopard"; assert_eq!(s.rfind(char::is_whitespace), Some(12)); assert_eq!(s.rfind(char::is_lowercase), Some(20));
Not finding the pattern:
let s = "Löwe 老虎 Léopard"; let x: &[_] = &['1', '2']; assert_eq!(s.rfind(x), None);
fn split<'a, P>(&'a self, pat: P) -> Split<'a, P> where P: Pattern<'a>
An iterator over substrings of self
, separated by characters
matched by a pattern.
The pattern can be a simple &str
, char
, or a closure that
determines the split. Additional libraries might provide more complex
patterns like regular expressions.
Iterator behavior
The returned iterator will be double ended if the pattern allows a
reverse search and forward/reverse search yields the same elements.
This is true for, eg, char
but not
for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, rsplit()
can be used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lamb".split(' ').collect(); assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]); let v: Vec<&str> = "".split('X').collect(); assert_eq!(v, [""]); let v: Vec<&str> = "lionXXtigerXleopard".split('X').collect(); assert_eq!(v, ["lion", "", "tiger", "leopard"]); let v: Vec<&str> = "lion::tiger::leopard".split("::").collect(); assert_eq!(v, ["lion", "tiger", "leopard"]); let v: Vec<&str> = "abc1def2ghi".split(char::is_numeric).collect(); assert_eq!(v, ["abc", "def", "ghi"]); let v: Vec<&str> = "lionXtigerXleopard".split(char::is_uppercase).collect(); assert_eq!(v, ["lion", "tiger", "leopard"]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".split(|c| c == '1' || c == 'X').collect(); assert_eq!(v, ["abc", "def", "ghi"]);
If a string contains multiple contiguous separators, you will end up with empty strings in the output:
let x = "||||a||b|c".to_string(); let d: Vec<_> = x.split('|').collect(); assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]);
This can lead to possibly surprising behavior when whitespace is used as the separator. This code is correct:
let x = " a b c".to_string(); let d: Vec<_> = x.split(' ').collect(); assert_eq!(d, &["", "", "", "", "a", "", "b", "c"]);
It does not give you:
assert_eq!(d, &["a", "b", "c"]);
Use .split_whitespace()
for this behavior.
fn rsplit<'a, P>(&'a self, pat: P) -> RSplit<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
An iterator over substrings of self
, separated by characters
matched by a pattern and yielded in reverse order.
The pattern can be a simple &str
, char
, or a closure that
determines the split.
Additional libraries might provide more complex patterns like
regular expressions.
Iterator behavior
The returned iterator requires that the pattern supports a reverse search, and it will be double ended if a forward/reverse search yields the same elements.
For iterating from the front, split()
can be used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lamb".rsplit(' ').collect(); assert_eq!(v, ["lamb", "little", "a", "had", "Mary"]); let v: Vec<&str> = "".rsplit('X').collect(); assert_eq!(v, [""]); let v: Vec<&str> = "lionXXtigerXleopard".rsplit('X').collect(); assert_eq!(v, ["leopard", "tiger", "", "lion"]); let v: Vec<&str> = "lion::tiger::leopard".rsplit("::").collect(); assert_eq!(v, ["leopard", "tiger", "lion"]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".rsplit(|c| c == '1' || c == 'X').collect(); assert_eq!(v, ["ghi", "def", "abc"]);
fn split_terminator<'a, P>(&'a self, pat: P) -> SplitTerminator<'a, P> where P: Pattern<'a>
An iterator over substrings of self
, separated by characters
matched by a pattern.
The pattern can be a simple &str
, char
, or a closure that
determines the split.
Additional libraries might provide more complex patterns
like regular expressions.
Equivalent to split
, except that the trailing substring
is skipped if empty.
This method can be used for string data that is terminated, rather than separated by a pattern.
Iterator behavior
The returned iterator will be double ended if the pattern allows a
reverse search
and forward/reverse search yields the same elements. This is true
for, eg, char
but not for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, rsplit_terminator()
can be used.
Examples
let v: Vec<&str> = "A.B.".split_terminator('.').collect(); assert_eq!(v, ["A", "B"]); let v: Vec<&str> = "A..B..".split_terminator(".").collect(); assert_eq!(v, ["A", "", "B", ""]);
fn rsplit_terminator<'a, P>(&'a self, pat: P) -> RSplitTerminator<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
An iterator over substrings of self
, separated by characters
matched by a pattern and yielded in reverse order.
The pattern can be a simple &str
, char
, or a closure that
determines the split.
Additional libraries might provide more complex patterns like
regular expressions.
Equivalent to split
, except that the trailing substring is
skipped if empty.
This method can be used for string data that is terminated, rather than separated by a pattern.
Iterator behavior
The returned iterator requires that the pattern supports a reverse search, and it will be double ended if a forward/reverse search yields the same elements.
For iterating from the front, split_terminator()
can be used.
Examples
let v: Vec<&str> = "A.B.".rsplit_terminator('.').collect(); assert_eq!(v, ["B", "A"]); let v: Vec<&str> = "A..B..".rsplit_terminator(".").collect(); assert_eq!(v, ["", "B", "", "A"]);
fn splitn<'a, P>(&'a self, count: usize, pat: P) -> SplitN<'a, P> where P: Pattern<'a>
An iterator over substrings of self
, separated by a pattern,
restricted to returning
at most count
items.
The last element returned, if any, will contain the remainder of the
string.
The pattern can be a simple &str
, char
, or a closure that
determines the split.
Additional libraries might provide more complex patterns like
regular expressions.
Iterator behavior
The returned iterator will not be double ended, because it is not efficient to support.
If the pattern allows a reverse search, rsplitn()
can be used.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lambda".splitn(3, ' ').collect(); assert_eq!(v, ["Mary", "had", "a little lambda"]); let v: Vec<&str> = "lionXXtigerXleopard".splitn(3, "X").collect(); assert_eq!(v, ["lion", "", "tigerXleopard"]); let v: Vec<&str> = "abcXdef".splitn(1, 'X').collect(); assert_eq!(v, ["abcXdef"]); let v: Vec<&str> = "".splitn(1, 'X').collect(); assert_eq!(v, [""]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".splitn(2, |c| c == '1' || c == 'X').collect(); assert_eq!(v, ["abc", "defXghi"]);
fn rsplitn<'a, P>(&'a self, count: usize, pat: P) -> RSplitN<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
An iterator over substrings of self
, separated by a pattern,
starting from the end of the string, restricted to returning
at most count
items.
The last element returned, if any, will contain the remainder of the string.
The pattern can be a simple &str
, char
, or a closure that
determines the split.
Additional libraries might provide more complex patterns like
regular expressions.
Iterator behavior
The returned iterator will not be double ended, because it is not efficient to support.
splitn()
can be used for splitting from the front.
Examples
Simple patterns:
let v: Vec<&str> = "Mary had a little lamb".rsplitn(3, ' ').collect(); assert_eq!(v, ["lamb", "little", "Mary had a"]); let v: Vec<&str> = "lionXXtigerXleopard".rsplitn(3, 'X').collect(); assert_eq!(v, ["leopard", "tiger", "lionX"]); let v: Vec<&str> = "lion::tiger::leopard".rsplitn(2, "::").collect(); assert_eq!(v, ["leopard", "lion::tiger"]);
A more complex pattern, using a closure:
let v: Vec<&str> = "abc1defXghi".rsplitn(2, |c| c == '1' || c == 'X').collect(); assert_eq!(v, ["ghi", "abc1def"]);
fn matches<'a, P>(&'a self, pat: P) -> Matches<'a, P> where P: Pattern<'a>
An iterator over the matches of a pattern within self
.
The pattern can be a simple &str
, char
, or a closure that
determines if a character matches.
Additional libraries might provide more complex patterns like
regular expressions.
Iterator behavior
The returned iterator will be double ended if the pattern allows
a reverse search
and forward/reverse search yields the same elements. This is true
for, eg, char
but not
for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, rmatches()
can be used.
Examples
let v: Vec<&str> = "abcXXXabcYYYabc".matches("abc").collect(); assert_eq!(v, ["abc", "abc", "abc"]); let v: Vec<&str> = "1abc2abc3".matches(char::is_numeric).collect(); assert_eq!(v, ["1", "2", "3"]);
fn rmatches<'a, P>(&'a self, pat: P) -> RMatches<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
An iterator over the matches of a pattern within self
, yielded in
reverse order.
The pattern can be a simple &str
, char
, or a closure that
determines if a character matches.
Additional libraries might provide more complex patterns like
regular expressions.
Iterator behavior
The returned iterator requires that the pattern supports a reverse search, and it will be double ended if a forward/reverse search yields the same elements.
For iterating from the front, matches()
can be used.
Examples
let v: Vec<&str> = "abcXXXabcYYYabc".rmatches("abc").collect(); assert_eq!(v, ["abc", "abc", "abc"]); let v: Vec<&str> = "1abc2abc3".rmatches(char::is_numeric).collect(); assert_eq!(v, ["3", "2", "1"]);
fn match_indices<'a, P>(&'a self, pat: P) -> MatchIndices<'a, P> where P: Pattern<'a>
str_match_indices
): might have its iterator type changed
An iterator over the disjoint matches of a pattern within self
as well
as the index that the match starts at.
For matches of pat
within self
that overlap, only the indices
corresponding to the first match are returned.
The pattern can be a simple &str
, char
, or a closure that determines
if a character matches. Additional libraries might provide more complex
patterns like regular expressions.
Iterator behavior
The returned iterator will be double ended if the pattern allows a
reverse search and forward/reverse search yields the same elements. This
is true for, eg, char
but not for &str
.
If the pattern allows a reverse search but its results might differ
from a forward search, rmatch_indices()
can be used.
Examples
#![feature(str_match_indices)] let v: Vec<_> = "abcXXXabcYYYabc".match_indices("abc").collect(); assert_eq!(v, [(0, "abc"), (6, "abc"), (12, "abc")]); let v: Vec<_> = "1abcabc2".match_indices("abc").collect(); assert_eq!(v, [(1, "abc"), (4, "abc")]); let v: Vec<_> = "ababa".match_indices("aba").collect(); assert_eq!(v, [(0, "aba")]); // only the first `aba`
fn rmatch_indices<'a, P>(&'a self, pat: P) -> RMatchIndices<'a, P> where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
str_match_indices
): might have its iterator type changed
An iterator over the disjoint matches of a pattern within self
,
yielded in reverse order along with the index of the match.
For matches of pat
within self
that overlap, only the indices
corresponding to the last match are returned.
The pattern can be a simple &str
, char
, or a closure that determines
if a character matches. Additional libraries might provide more complex
patterns like regular expressions.
Iterator behavior
The returned iterator requires that the pattern supports a reverse search, and it will be double ended if a forward/reverse search yields the same elements.
For iterating from the front, match_indices()
can be used.
Examples
#![feature(str_match_indices)] let v: Vec<_> = "abcXXXabcYYYabc".rmatch_indices("abc").collect(); assert_eq!(v, [(12, "abc"), (6, "abc"), (0, "abc")]); let v: Vec<_> = "1abcabc2".rmatch_indices("abc").collect(); assert_eq!(v, [(4, "abc"), (1, "abc")]); let v: Vec<_> = "ababa".rmatch_indices("aba").collect(); assert_eq!(v, [(2, "aba")]); // only the last `aba`
fn trim(&self) -> &str
Returns a &str
with leading and trailing whitespace removed.
Examples
let s = " Hello\tworld\t"; assert_eq!(s.trim(), "Hello\tworld");
fn trim_left(&self) -> &str
Returns a &str
with leading whitespace removed.
Examples
let s = " Hello\tworld\t"; assert_eq!(s.trim_left(), "Hello\tworld\t");
fn trim_right(&self) -> &str
Returns a &str
with trailing whitespace removed.
Examples
let s = " Hello\tworld\t"; assert_eq!(s.trim_right(), " Hello\tworld");
fn trim_matches<'a, P>(&'a self, pat: P) -> &'a str where P: Pattern<'a>, P::Searcher: DoubleEndedSearcher<'a>
Returns a string with all pre- and suffixes that match a pattern repeatedly removed.
The pattern can be a simple char
, or a closure that determines
if a character matches.
Examples
Simple patterns:
assert_eq!("11foo1bar11".trim_matches('1'), "foo1bar"); assert_eq!("123foo1bar123".trim_matches(char::is_numeric), "foo1bar"); let x: &[_] = &['1', '2']; assert_eq!("12foo1bar12".trim_matches(x), "foo1bar");
A more complex pattern, using a closure:
assert_eq!("1foo1barXX".trim_matches(|c| c == '1' || c == 'X'), "foo1bar");
fn trim_left_matches<'a, P>(&'a self, pat: P) -> &'a str where P: Pattern<'a>
Returns a string with all prefixes that match a pattern repeatedly removed.
The pattern can be a simple &str
, char
, or a closure that
determines if a character matches.
Examples
assert_eq!("11foo1bar11".trim_left_matches('1'), "foo1bar11"); assert_eq!("123foo1bar123".trim_left_matches(char::is_numeric), "foo1bar123"); let x: &[_] = &['1', '2']; assert_eq!("12foo1bar12".trim_left_matches(x), "foo1bar12");
fn trim_right_matches<'a, P>(&'a self, pat: P) -> &'a str where P: Pattern<'a>, P::Searcher: ReverseSearcher<'a>
Returns a string with all suffixes that match a pattern repeatedly removed.
The pattern can be a simple &str
, char
, or a closure that
determines if a character matches.
Examples
Simple patterns:
assert_eq!("11foo1bar11".trim_right_matches('1'), "11foo1bar"); assert_eq!("123foo1bar123".trim_right_matches(char::is_numeric), "123foo1bar"); let x: &[_] = &['1', '2']; assert_eq!("12foo1bar12".trim_right_matches(x), "12foo1bar");
A more complex pattern, using a closure:
assert_eq!("1fooX".trim_left_matches(|c| c == '1' || c == 'X'), "fooX");
fn parse<F>(&self) -> Result<F, F::Err> where F: FromStr
Parses self
into the specified type.
Failure
Will return Err
if it's not possible to parse self
into the type.
Example
assert_eq!("4".parse::<u32>(), Ok(4));
Failing:
assert!("j".parse::<u32>().is_err());
fn replace(&self, from: &str, to: &str) -> String
Replaces all occurrences of one string with another.
replace
takes two arguments, a sub-&str
to find in self
, and a
second &str
to
replace it with. If the original &str
isn't found, no change occurs.
Examples
let s = "this is old"; assert_eq!(s.replace("old", "new"), "this is new");
When a &str
isn't found:
let s = "this is old"; assert_eq!(s.replace("cookie monster", "little lamb"), s);
fn to_lowercase(&self) -> String
Returns the lowercase equivalent of this string.
Examples
let s = "HELLO"; assert_eq!(s.to_lowercase(), "hello");
fn to_uppercase(&self) -> String
Returns the uppercase equivalent of this string.
Examples
let s = "hello"; assert_eq!(s.to_uppercase(), "HELLO");
fn escape_default(&self) -> String
str_escape
): return type may change to be an iterator
Escapes each char in s
with char::escape_default
.
fn escape_unicode(&self) -> String
str_escape
): return type may change to be an iterator
Escapes each char in s
with char::escape_unicode
.
fn into_string(self: Box<str>) -> String
Converts the Box<str>
into a String
without copying or allocating.