+
Returns the length of self
in bytes.
+
+
+assert_eq!("foo".len(), 3);
+assert_eq!("ƒoo".len(), 4);
+
+
+
Returns true if this slice has a length of zero bytes.
+
+
+assert!("".is_empty());
+
+
+
Deprecated since 1.0.0: use the crates.io unicode-width
library instead
+ Returns a string's displayed width in columns.
+
+
Control characters have zero width.
+
+
is_cjk
determines behavior for characters in the Ambiguous category:
+if is_cjk
is
+true
, these are 2 columns wide; otherwise, they are 1.
+In CJK locales, is_cjk
should be
+true
, else it should be false
.
+Unicode Standard Annex #11
+recommends that these
+characters be treated as 1 column (i.e., is_cjk = false
) if the
+locale is unknown.
+
+
Unstable: 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.
+
+
+
Panics if index
is greater than self.len()
.
+
+
+let s = "Löwe 老虎 Léopard";
+assert!(s.is_char_boundary(0));
+
+assert!(s.is_char_boundary(6));
+assert!(s.is_char_boundary(s.len()));
+
+
+assert!(!s.is_char_boundary(2));
+
+
+assert!(!s.is_char_boundary(8));
+
+
+
Converts self
to a byte slice.
+
+
+assert_eq!("bors".as_bytes(), b"bors");
+
+
+
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).
+
+
+let s = "Hello";
+let p = s.as_ptr();
+
+
+
Takes a bytewise slice from a string.
+
+
Returns the substring from [begin
..end
).
+
+
+
Caller must check both UTF-8 character boundaries and the boundaries
+of the entire slice as
+well.
+
+
+let s = "Löwe 老虎 Léopard";
+
+unsafe {
+ assert_eq!(s.slice_unchecked(0, 21), "Löwe 老虎 Léopard");
+}
+
+
+
Unstable: may have yet to prove its worth
+ Returns a slice of the string from the character range [begin
..end
).
+
+
That is, start at the begin
-th code point of the string and continue
+to the end
-th code point. This does not detect or handle edge cases
+such as leaving a combining character as the first code point of the
+string.
+
+
Due to the design of UTF-8, this operation is O(end)
. Use slicing
+syntax if you want to use byte indices rather than codepoint indices.
+
+
+
Panics if begin
> end
or the either begin
or end
are beyond the
+last character of the string.
+
+
+let s = "Löwe 老虎 Léopard";
+
+assert_eq!(s.slice_chars(0, 4), "Löwe");
+assert_eq!(s.slice_chars(5, 7), "老虎");
+
+
+
Unstable: 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 char and its index.
+
+
This can be used to iterate over the Unicode characters of a string.
+
+
+
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 character.
+
+
+
This example manually iterates through the characters of a string;
+this should normally be
+done by .chars()
or .char_indices()
.
+
+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: ệ
+11: t
+12:
+13: N
+14: a
+15: m
+
+
+
Unstable: 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 string in reverse.
+
+
Returns 0 for next index if called on start index 0.
+
+
+
If i
is greater than the length of the string.
+If i
is not an index following a valid UTF-8 character.
+
+
+
This example manually iterates through the characters of a string;
+this should normally be
+done by .chars().rev()
or .char_indices()
.
+
+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:
+
+
16: m
+15: a
+14: N
+13:
+12: t
+11: ệ
+8: i
+7: V
+6: 华
+3: 中
+
+
+
Unstable: 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.
+
+
+
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 character.
+
+
+let s = "abπc";
+assert_eq!(s.char_at(1), 'b');
+assert_eq!(s.char_at(2), 'π');
+
+
+
Unstable: 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.
+
+
+
If i
is greater than the length of the string.
+If i
is not an index following a valid UTF-8 character.
+
+
+let s = "abπc";
+assert_eq!(s.char_at_reverse(1), 'a');
+assert_eq!(s.char_at_reverse(2), 'b');
+
+
+
Unstable: 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 character from a &str
and returns it.
+
+
This does not allocate a new string; instead, it returns a slice that
+points one character
+beyond the character that was shifted.
+
+
If the slice does not contain any characters, None is returned instead.
+
+
+let s = "Löwe 老虎 Léopard";
+let (c, s1) = s.slice_shift_char().unwrap();
+
+assert_eq!(c, 'L');
+assert_eq!(s1, "öwe 老虎 Léopard");
+
+let (c, s2) = s1.slice_shift_char().unwrap();
+
+assert_eq!(c, 'ö');
+assert_eq!(s2, "we 老虎 Léopard");
+
+
+
Unstable: library is unlikely to be stabilized with the current layout and name, use std::collections instead
+ 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 character boundary.
+
+
Return slices &self[..mid]
and &self[mid..]
.
+
+
+
Panics if mid
is beyond the last character of the string,
+or if it is not on a character boundary.
+
+
+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");
+
+
+
An iterator over the codepoints of self
.
+
+
+let v: Vec<char> = "abc åäö".chars().collect();
+
+assert_eq!(v, ['a', 'b', 'c', ' ', 'å', 'ä', 'ö']);
+
+
+
An iterator over the characters of self
and their byte offsets.
+
+
+let v: Vec<(usize, char)> = "abc".char_indices().collect();
+let b = vec![(0, 'a'), (1, 'b'), (2, 'c')];
+
+assert_eq!(v, b);
+
+
+
An iterator over the bytes of self
.
+
+
+let v: Vec<u8> = "bors".bytes().collect();
+
+assert_eq!(v, b"bors".to_vec());
+
+
+
An iterator over the non-empty substrings of self
which contain no whitespace,
+and which are separated by any amount of whitespace.
+
+
+let some_words = " Mary had\ta little \n\t lamb";
+let v: Vec<&str> = some_words.split_whitespace().collect();
+
+assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]);
+
+
+
Deprecated since 1.1.0: words() will be removed. Use split_whitespace() instead
+ An iterator over the non-empty substrings of self
which contain no whitespace,
+and which are separated by any amount of whitespace.
+
+
+let some_words = " Mary had\ta little \n\t lamb";
+let v: Vec<&str> = some_words.words().collect();
+
+assert_eq!(v, ["Mary", "had", "a", "little", "lamb"]);
+
+
+
An iterator over the lines of a string, separated by \n
.
+
+
This does not include the empty string after a trailing \n
.
+
+
+let four_lines = "foo\nbar\n\nbaz";
+let v: Vec<&str> = four_lines.lines().collect();
+
+assert_eq!(v, ["foo", "bar", "", "baz"]);
+
+
+
Leaving off the trailing character:
+
+let four_lines = "foo\nbar\n\nbaz\n";
+let v: Vec<&str> = four_lines.lines().collect();
+
+assert_eq!(v, ["foo", "bar", "", "baz"]);
+
+
+
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.
+
+
+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"]);
+
+
+
Deprecated since 1.0.0: use the crates.io unicode-normalization
library instead
+ Returns an iterator over the string in Unicode Normalization Form D
+(canonical decomposition).
+
+
Deprecated since 1.0.0: use the crates.io unicode-normalization
library instead
+ Returns an iterator over the string in Unicode Normalization Form KD
+(compatibility decomposition).
+
+
Deprecated since 1.0.0: use the crates.io unicode-normalization
library instead
+ An Iterator over the string in Unicode Normalization Form C
+(canonical decomposition followed by canonical composition).
+
+
Deprecated since 1.0.0: use the crates.io unicode-normalization
library instead
+ An Iterator over the string in Unicode Normalization Form KC
+(compatibility decomposition followed by canonical composition).
+
+
Deprecated since 1.0.0: use the crates.io unicode-segmentation
library instead
+ Returns an iterator over the grapheme clusters of self
.
+
+
If is_extended
is true, the iterator is over the
+extended grapheme clusters;
+otherwise, the iterator is over the legacy grapheme clusters.
+UAX#29
+recommends extended grapheme cluster boundaries for general processing.
+
+
+let gr1 = "a\u{310}e\u{301}o\u{308}\u{332}".graphemes(true).collect::<Vec<&str>>();
+let b: &[_] = &["a\u{310}", "e\u{301}", "o\u{308}\u{332}"];
+
+assert_eq!(&gr1[..], b);
+
+let gr2 = "a\r\nb🇷🇺🇸🇹".graphemes(true).collect::<Vec<&str>>();
+let b: &[_] = &["a", "\r\n", "b", "🇷🇺🇸🇹"];
+
+assert_eq!(&gr2[..], b);
+
+
+
Deprecated since 1.0.0: use the crates.io unicode-segmentation
library instead
+ Returns an iterator over the grapheme clusters of self
and their
+byte offsets. See
+graphemes()
for more information.
+
+
+let gr_inds = "a̐éö̲\r\n".grapheme_indices(true).collect::<Vec<(usize, &str)>>();
+let b: &[_] = &[(0, "a̐"), (3, "é"), (6, "ö̲"), (11, "\r\n")];
+
+assert_eq!(&gr_inds[..], b);
+
+
+
Unstable: 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
.
+
+
+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.
+
+
+assert!("banana".starts_with("ba"));
+
+
+
Returns true if the given &str
is a suffix of the string.
+
+
+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 the
+split.
+
+
+
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);
+
+
+
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 the split.
+
+
+
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.
+
+
+
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.
+
+
+
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"]);
+
+
+
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.
+
+
+
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.
+
+
+
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"]);
+
+
+
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.
+
+
+
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.
+
+
+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", ""]);
+
+
+
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.
+
+
+
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.
+
+
+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.
+
+
+
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.
+
+
+
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"]);
+
+
+
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.
+
+
+
The returned iterator will not be double ended, because it is not
+efficient to support.
+
+
splitn()
can be used for splitting from the front.
+
+
+
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 the split.
+Additional libraries might provide more complex patterns like
+regular expressions.
+
+
+
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.
+
+
+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"]);
+
+
+
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 the split.
+Additional libraries might provide more complex patterns like
+regular expressions.
+
+
+
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.
+
+
+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"]);
+
+
+
Unstable: might have its iterator type changed
+ An iterator over the start and end indices of the disjoint matches
+of a pattern within self
.
+
+
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
+the split.
+Additional libraries might provide more complex patterns like
+regular expressions.
+
+
+
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.
+
+
+let v: Vec<(usize, usize)> = "abcXXXabcYYYabc".match_indices("abc").collect();
+assert_eq!(v, [(0, 3), (6, 9), (12, 15)]);
+
+let v: Vec<(usize, usize)> = "1abcabc2".match_indices("abc").collect();
+assert_eq!(v, [(1, 4), (4, 7)]);
+
+let v: Vec<(usize, usize)> = "ababa".match_indices("aba").collect();
+assert_eq!(v, [(0, 3)]);
+
+
+
Unstable: might have its iterator type changed
+ An iterator over the start and end indices of the disjoint matches of
+a pattern within
+self
, yielded in reverse order.
+
+
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
+the split.
+Additional libraries might provide more complex patterns like
+regular expressions.
+
+
+
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.
+
+
+let v: Vec<(usize, usize)> = "abcXXXabcYYYabc".rmatch_indices("abc").collect();
+assert_eq!(v, [(12, 15), (6, 9), (0, 3)]);
+
+let v: Vec<(usize, usize)> = "1abcabc2".rmatch_indices("abc").collect();
+assert_eq!(v, [(4, 7), (1, 4)]);
+
+let v: Vec<(usize, usize)> = "ababa".rmatch_indices("aba").collect();
+assert_eq!(v, [(2, 5)]);
+
+
+
Unstable: awaiting convention about comparability of arbitrary slices
+ Returns the byte offset of an inner slice relative to an enclosing
+outer slice.
+
+
+
Panics if inner
is not a direct slice contained within self.
+
+
+let string = "a\nb\nc";
+let lines: Vec<&str> = string.lines().collect();
+
+assert!(string.subslice_offset(lines[0]) == 0);
+assert!(string.subslice_offset(lines[1]) == 2);
+assert!(string.subslice_offset(lines[2]) == 4);
+
+
fn trim(&self) -> &str
+
Returns a &str
with leading and trailing whitespace removed.
+
+
+let s = " Hello\tworld\t";
+assert_eq!(s.trim(), "Hello\tworld");
+
+
+
Returns a &str
with leading whitespace removed.
+
+
+let s = " Hello\tworld\t";
+assert_eq!(s.trim_left(), "Hello\tworld\t");
+
+
+
Returns a &str
with trailing whitespace removed.
+
+
+let s = " Hello\tworld\t";
+assert_eq!(s.trim_right(), " Hello\tworld");
+
+
+
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
+the split.
+
+
+
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");
+
+
+
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 the split.
+
+
+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");
+
+
+
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 the split.
+
+
+
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");
+
+
+
Parses self
into the specified type.
+
+
+
Will return Err
if it's not possible to parse self
into the type.
+
+
+assert_eq!("4".parse::<u32>(), Ok(4));
+
+
+
Failing:
+
+assert!("j".parse::<u32>().is_err());
+
+
+
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.
+
+
+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);
+
+
+
Returns the lowercase equivalent of this string.
+
+
+#![feature(str_casing)]
+
+let s = "HELLO";
+assert_eq!(s.to_lowercase(), "hello");
+
+
+
Returns the uppercase equivalent of this string.
+
+
+#![feature(str_casing)]
+
+let s = "hello";
+assert_eq!(s.to_uppercase(), "HELLO");
+
+
+
Unstable: return type may change to be an iterator
+ Escapes each char in s
with char::escape_default
.
+
+
Unstable: return type may change to be an iterator
+ Escapes each char in s
with char::escape_unicode
.
+