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rollup merge of #23951: alexcrichton/splitn
This commit is an implementation of [RFC 979][rfc] which changes the meaning of the count parameter to the `splitn` function on strings and slices. The parameter now means the number of items that are returned from the iterator, not the number of splits that are made. [rfc]: https://github.com/rust-lang/rfcs/pull/979 Closes #23911 [breaking-change]
This commit is contained in:
commit
e9bacbaa2c
@ -311,7 +311,7 @@ fn parse_exec_env(line: &str) -> Option<(String, String)> {
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parse_name_value_directive(line, "exec-env").map(|nv| {
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// nv is either FOO or FOO=BAR
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let mut strs: Vec<String> = nv
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.splitn(1, '=')
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.splitn(2, '=')
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.map(|s| s.to_string())
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.collect();
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@ -328,9 +328,12 @@ impl<T> [T] {
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}
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/// Returns an iterator over subslices separated by elements that match
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/// `pred`, limited to splitting at most `n` times. The matched element is
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/// `pred`, limited to returning at most `n` items. The matched element is
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/// not contained in the subslices.
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///
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/// The last element returned, if any, will contain the remainder of the
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/// slice.
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///
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/// # Examples
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///
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/// Print the slice split once by numbers divisible by 3 (i.e. `[10, 40]`,
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@ -338,7 +341,7 @@ impl<T> [T] {
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///
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/// ```
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/// let v = [10, 40, 30, 20, 60, 50];
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/// for group in v.splitn(1, |num| *num % 3 == 0) {
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/// for group in v.splitn(2, |num| *num % 3 == 0) {
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/// println!("{:?}", group);
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/// }
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/// ```
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@ -349,10 +352,13 @@ impl<T> [T] {
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}
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/// Returns an iterator over subslices separated by elements that match
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/// `pred` limited to splitting at most `n` times. This starts at the end of
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/// `pred` limited to returning at most `n` items. This starts at the end of
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/// the slice and works backwards. The matched element is not contained in
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/// the subslices.
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///
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/// The last element returned, if any, will contain the remainder of the
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/// slice.
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///
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/// # Examples
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///
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/// Print the slice split once, starting from the end, by numbers divisible
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@ -360,7 +366,7 @@ impl<T> [T] {
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///
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/// ```
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/// let v = [10, 40, 30, 20, 60, 50];
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/// for group in v.rsplitn(1, |num| *num % 3 == 0) {
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/// for group in v.rsplitn(2, |num| *num % 3 == 0) {
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/// println!("{:?}", group);
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/// }
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/// ```
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@ -626,8 +632,11 @@ impl<T> [T] {
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}
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/// Returns an iterator over subslices separated by elements that match
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/// `pred`, limited to splitting at most `n` times. The matched element is
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/// `pred`, limited to returning at most `n` items. The matched element is
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/// not contained in the subslices.
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///
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/// The last element returned, if any, will contain the remainder of the
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/// slice.
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#[stable(feature = "rust1", since = "1.0.0")]
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#[inline]
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pub fn splitn_mut<F>(&mut self, n: usize, pred: F) -> SplitNMut<T, F>
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@ -636,9 +645,12 @@ impl<T> [T] {
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}
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/// Returns an iterator over subslices separated by elements that match
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/// `pred` limited to splitting at most `n` times. This starts at the end of
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/// `pred` limited to returning at most `n` items. This starts at the end of
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/// the slice and works backwards. The matched element is not contained in
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/// the subslices.
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///
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/// The last element returned, if any, will contain the remainder of the
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/// slice.
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#[stable(feature = "rust1", since = "1.0.0")]
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#[inline]
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pub fn rsplitn_mut<F>(&mut self, n: usize, pred: F) -> RSplitNMut<T, F>
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@ -610,24 +610,27 @@ impl str {
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core_str::StrExt::split(&self[..], pat)
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}
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/// An iterator over substrings of `self`, separated by characters matched by a pattern,
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/// restricted to splitting at most `count` times.
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/// An iterator over substrings of `self`, separated by characters matched
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/// by a pattern, returning most `count` items.
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///
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/// The pattern can be a simple `&str`, or a closure that determines
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/// the split.
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///
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/// The last element returned, if any, will contain the remainder of the
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/// string.
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///
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/// # Examples
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///
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/// Simple `&str` patterns:
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///
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/// ```
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/// let v: Vec<&str> = "Mary had a little lambda".splitn(2, ' ').collect();
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/// assert_eq!(v, ["Mary", "had", "a little lambda"]);
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/// assert_eq!(v, ["Mary", "had a little lambda"]);
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///
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/// let v: Vec<&str> = "lionXXtigerXleopard".splitn(2, 'X').collect();
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/// assert_eq!(v, ["lion", "", "tigerXleopard"]);
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/// assert_eq!(v, ["lion", "XtigerXleopard"]);
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///
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/// let v: Vec<&str> = "abcXdef".splitn(0, 'X').collect();
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/// let v: Vec<&str> = "abcXdef".splitn(1, 'X').collect();
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/// assert_eq!(v, ["abcXdef"]);
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///
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/// let v: Vec<&str> = "".splitn(1, 'X').collect();
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@ -637,7 +640,7 @@ impl str {
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/// More complex patterns with a lambda:
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///
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/// ```
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/// let v: Vec<&str> = "abc1def2ghi".splitn(1, |c: char| c.is_numeric()).collect();
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/// let v: Vec<&str> = "abc1def2ghi".splitn(2, |c: char| c.is_numeric()).collect();
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/// assert_eq!(v, ["abc", "def2ghi"]);
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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@ -705,25 +708,28 @@ impl str {
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}
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/// An iterator over substrings of `self`, separated by a pattern,
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/// starting from the end of the string, restricted to splitting
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/// at most `count` times.
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/// starting from the end of the string, restricted to returning
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/// at most `count` items.
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///
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/// The last element returned, if any, will contain the remainder of the
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/// string.
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///
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/// # Examples
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///
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/// Simple patterns:
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///
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/// ```
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/// let v: Vec<&str> = "Mary had a little lamb".rsplitn(2, ' ').collect();
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/// let v: Vec<&str> = "Mary had a little lamb".rsplitn(3, ' ').collect();
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/// assert_eq!(v, ["lamb", "little", "Mary had a"]);
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///
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/// let v: Vec<&str> = "lion::tiger::leopard".rsplitn(1, "::").collect();
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/// let v: Vec<&str> = "lion::tiger::leopard".rsplitn(2, "::").collect();
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/// assert_eq!(v, ["leopard", "lion::tiger"]);
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/// ```
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///
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/// More complex patterns with a lambda:
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///
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/// ```
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/// let v: Vec<&str> = "abc1def2ghi".rsplitn(1, |c: char| c.is_numeric()).collect();
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/// let v: Vec<&str> = "abc1def2ghi".rsplitn(2, |c: char| c.is_numeric()).collect();
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/// assert_eq!(v, ["ghi", "abc1def"]);
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/// ```
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#[stable(feature = "rust1", since = "1.0.0")]
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@ -867,18 +867,18 @@ fn test_splitnator() {
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let xs = &[1,2,3,4,5];
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let splits: &[&[_]] = &[&[1,2,3,4,5]];
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assert_eq!(xs.splitn(0, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&[_]] = &[&[1], &[3,4,5]];
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assert_eq!(xs.splitn(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&[_]] = &[&[1], &[3,4,5]];
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assert_eq!(xs.splitn(2, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&[_]] = &[&[], &[], &[], &[4,5]];
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assert_eq!(xs.splitn(3, |_| true).collect::<Vec<_>>(),
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assert_eq!(xs.splitn(4, |_| true).collect::<Vec<_>>(),
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splits);
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let xs: &[i32] = &[];
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let splits: &[&[i32]] = &[&[]];
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assert_eq!(xs.splitn(1, |x| *x == 5).collect::<Vec<_>>(), splits);
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assert_eq!(xs.splitn(2, |x| *x == 5).collect::<Vec<_>>(), splits);
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}
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#[test]
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@ -886,18 +886,18 @@ fn test_splitnator_mut() {
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let xs = &mut [1,2,3,4,5];
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let splits: &[&mut[_]] = &[&mut [1,2,3,4,5]];
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assert_eq!(xs.splitn_mut(0, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&mut[_]] = &[&mut [1], &mut [3,4,5]];
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assert_eq!(xs.splitn_mut(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&mut[_]] = &[&mut [1], &mut [3,4,5]];
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assert_eq!(xs.splitn_mut(2, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&mut[_]] = &[&mut [], &mut [], &mut [], &mut [4,5]];
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assert_eq!(xs.splitn_mut(3, |_| true).collect::<Vec<_>>(),
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assert_eq!(xs.splitn_mut(4, |_| true).collect::<Vec<_>>(),
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splits);
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let xs: &mut [i32] = &mut [];
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let splits: &[&mut[i32]] = &[&mut []];
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assert_eq!(xs.splitn_mut(1, |x| *x == 5).collect::<Vec<_>>(),
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assert_eq!(xs.splitn_mut(2, |x| *x == 5).collect::<Vec<_>>(),
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splits);
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}
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@ -928,18 +928,19 @@ fn test_rsplitnator() {
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let xs = &[1,2,3,4,5];
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let splits: &[&[_]] = &[&[1,2,3,4,5]];
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assert_eq!(xs.rsplitn(0, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&[_]] = &[&[5], &[1,2,3]];
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assert_eq!(xs.rsplitn(1, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&[_]] = &[&[5], &[1,2,3]];
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assert_eq!(xs.rsplitn(2, |x| *x % 2 == 0).collect::<Vec<_>>(),
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splits);
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let splits: &[&[_]] = &[&[], &[], &[], &[1,2]];
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assert_eq!(xs.rsplitn(3, |_| true).collect::<Vec<_>>(),
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assert_eq!(xs.rsplitn(4, |_| true).collect::<Vec<_>>(),
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splits);
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let xs: &[i32] = &[];
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let splits: &[&[i32]] = &[&[]];
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assert_eq!(xs.rsplitn(1, |x| *x == 5).collect::<Vec<&[i32]>>(), splits);
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assert_eq!(xs.rsplitn(2, |x| *x == 5).collect::<Vec<&[i32]>>(), splits);
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assert!(xs.rsplitn(0, |x| *x % 2 == 0).next().is_none());
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}
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#[test]
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|
@ -885,17 +885,17 @@ fn test_char_indices_revator() {
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fn test_splitn_char_iterator() {
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let data = "\nMäry häd ä little lämb\nLittle lämb\n";
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let split: Vec<&str> = data.splitn(3, ' ').collect();
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let split: Vec<&str> = data.splitn(4, ' ').collect();
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assert_eq!(split, ["\nMäry", "häd", "ä", "little lämb\nLittle lämb\n"]);
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let split: Vec<&str> = data.splitn(3, |c: char| c == ' ').collect();
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let split: Vec<&str> = data.splitn(4, |c: char| c == ' ').collect();
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assert_eq!(split, ["\nMäry", "häd", "ä", "little lämb\nLittle lämb\n"]);
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// Unicode
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let split: Vec<&str> = data.splitn(3, 'ä').collect();
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let split: Vec<&str> = data.splitn(4, 'ä').collect();
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assert_eq!(split, ["\nM", "ry h", "d ", " little lämb\nLittle lämb\n"]);
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let split: Vec<&str> = data.splitn(3, |c: char| c == 'ä').collect();
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let split: Vec<&str> = data.splitn(4, |c: char| c == 'ä').collect();
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assert_eq!(split, ["\nM", "ry h", "d ", " little lämb\nLittle lämb\n"]);
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}
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@ -928,13 +928,13 @@ fn test_rsplit() {
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fn test_rsplitn() {
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let data = "\nMäry häd ä little lämb\nLittle lämb\n";
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let split: Vec<&str> = data.rsplitn(1, ' ').collect();
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let split: Vec<&str> = data.rsplitn(2, ' ').collect();
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assert_eq!(split, ["lämb\n", "\nMäry häd ä little lämb\nLittle"]);
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let split: Vec<&str> = data.rsplitn(1, "lämb").collect();
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let split: Vec<&str> = data.rsplitn(2, "lämb").collect();
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assert_eq!(split, ["\n", "\nMäry häd ä little lämb\nLittle "]);
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let split: Vec<&str> = data.rsplitn(1, |c: char| c == 'ä').collect();
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let split: Vec<&str> = data.rsplitn(2, |c: char| c == 'ä').collect();
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assert_eq!(split, ["mb\n", "\nMäry häd ä little lämb\nLittle l"]);
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}
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|
@ -1126,18 +1126,20 @@ impl<T, I: SplitIter<Item=T>> Iterator for GenericSplitN<I> {
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#[inline]
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fn next(&mut self) -> Option<T> {
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if self.count == 0 {
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self.iter.finish()
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} else {
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self.count -= 1;
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if self.invert { self.iter.next_back() } else { self.iter.next() }
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match self.count {
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0 => None,
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1 => { self.count -= 1; self.iter.finish() }
|
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_ => {
|
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self.count -= 1;
|
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if self.invert {self.iter.next_back()} else {self.iter.next()}
|
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}
|
||||
}
|
||||
}
|
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|
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#[inline]
|
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fn size_hint(&self) -> (usize, Option<usize>) {
|
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let (lower, upper_opt) = self.iter.size_hint();
|
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(lower, upper_opt.map(|upper| cmp::min(self.count + 1, upper)))
|
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(lower, upper_opt.map(|upper| cmp::min(self.count, upper)))
|
||||
}
|
||||
}
|
||||
|
||||
|
@ -489,7 +489,7 @@ struct CharSplits<'a, P: Pattern<'a>> {
|
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/// splitting at most `count` times.
|
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struct CharSplitsN<'a, P: Pattern<'a>> {
|
||||
iter: CharSplits<'a, P>,
|
||||
/// The number of splits remaining
|
||||
/// The number of items remaining
|
||||
count: usize,
|
||||
}
|
||||
|
||||
@ -596,11 +596,10 @@ impl<'a, P: Pattern<'a>> Iterator for CharSplitsN<'a, P> {
|
||||
|
||||
#[inline]
|
||||
fn next(&mut self) -> Option<&'a str> {
|
||||
if self.count != 0 {
|
||||
self.count -= 1;
|
||||
self.iter.next()
|
||||
} else {
|
||||
self.iter.get_end()
|
||||
match self.count {
|
||||
0 => None,
|
||||
1 => { self.count = 0; self.iter.get_end() }
|
||||
_ => { self.count -= 1; self.iter.next() }
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -650,11 +649,10 @@ impl<'a, P: Pattern<'a>> Iterator for RCharSplitsN<'a, P>
|
||||
|
||||
#[inline]
|
||||
fn next(&mut self) -> Option<&'a str> {
|
||||
if self.count != 0 {
|
||||
self.count -= 1;
|
||||
self.iter.next()
|
||||
} else {
|
||||
self.iter.get_remainder()
|
||||
match self.count {
|
||||
0 => None,
|
||||
1 => { self.count -= 1; self.iter.get_remainder() }
|
||||
_ => { self.count -= 1; self.iter.next() }
|
||||
}
|
||||
}
|
||||
}
|
||||
|
@ -65,20 +65,20 @@ fn test_strslice_contains() {
|
||||
fn test_rsplitn_char_iterator() {
|
||||
let data = "\nMäry häd ä little lämb\nLittle lämb\n";
|
||||
|
||||
let mut split: Vec<&str> = data.rsplitn(3, ' ').collect();
|
||||
let mut split: Vec<&str> = data.rsplitn(4, ' ').collect();
|
||||
split.reverse();
|
||||
assert_eq!(split, ["\nMäry häd ä", "little", "lämb\nLittle", "lämb\n"]);
|
||||
|
||||
let mut split: Vec<&str> = data.rsplitn(3, |c: char| c == ' ').collect();
|
||||
let mut split: Vec<&str> = data.rsplitn(4, |c: char| c == ' ').collect();
|
||||
split.reverse();
|
||||
assert_eq!(split, ["\nMäry häd ä", "little", "lämb\nLittle", "lämb\n"]);
|
||||
|
||||
// Unicode
|
||||
let mut split: Vec<&str> = data.rsplitn(3, 'ä').collect();
|
||||
let mut split: Vec<&str> = data.rsplitn(4, 'ä').collect();
|
||||
split.reverse();
|
||||
assert_eq!(split, ["\nMäry häd ", " little l", "mb\nLittle l", "mb\n"]);
|
||||
|
||||
let mut split: Vec<&str> = data.rsplitn(3, |c: char| c == 'ä').collect();
|
||||
let mut split: Vec<&str> = data.rsplitn(4, |c: char| c == 'ä').collect();
|
||||
split.reverse();
|
||||
assert_eq!(split, ["\nMäry häd ", " little l", "mb\nLittle l", "mb\n"]);
|
||||
}
|
||||
|
@ -304,7 +304,7 @@ macro_rules! options {
|
||||
{
|
||||
let mut op = $defaultfn();
|
||||
for option in matches.opt_strs($prefix) {
|
||||
let mut iter = option.splitn(1, '=');
|
||||
let mut iter = option.splitn(2, '=');
|
||||
let key = iter.next().unwrap();
|
||||
let value = iter.next();
|
||||
let option_to_lookup = key.replace("-", "_");
|
||||
@ -958,7 +958,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
|
||||
}
|
||||
|
||||
let libs = matches.opt_strs("l").into_iter().map(|s| {
|
||||
let mut parts = s.splitn(1, '=');
|
||||
let mut parts = s.splitn(2, '=');
|
||||
let kind = parts.next().unwrap();
|
||||
let (name, kind) = match (parts.next(), kind) {
|
||||
(None, name) |
|
||||
@ -1010,7 +1010,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
|
||||
|
||||
let mut externs = HashMap::new();
|
||||
for arg in &matches.opt_strs("extern") {
|
||||
let mut parts = arg.splitn(1, '=');
|
||||
let mut parts = arg.splitn(2, '=');
|
||||
let name = match parts.next() {
|
||||
Some(s) => s,
|
||||
None => early_error("--extern value must not be empty"),
|
||||
|
@ -74,7 +74,7 @@ pub enum PpMode {
|
||||
pub fn parse_pretty(sess: &Session,
|
||||
name: &str,
|
||||
extended: bool) -> (PpMode, Option<UserIdentifiedItem>) {
|
||||
let mut split = name.splitn(1, '=');
|
||||
let mut split = name.splitn(2, '=');
|
||||
let first = split.next().unwrap();
|
||||
let opt_second = split.next();
|
||||
let first = match (first, extended) {
|
||||
|
@ -333,7 +333,7 @@ fn acquire_input(input: &str,
|
||||
fn parse_externs(matches: &getopts::Matches) -> Result<core::Externs, String> {
|
||||
let mut externs = HashMap::new();
|
||||
for arg in &matches.opt_strs("extern") {
|
||||
let mut parts = arg.splitn(1, '=');
|
||||
let mut parts = arg.splitn(2, '=');
|
||||
let name = match parts.next() {
|
||||
Some(s) => s,
|
||||
None => {
|
||||
|
@ -441,7 +441,7 @@ impl ToSocketAddrs for str {
|
||||
}
|
||||
|
||||
// split the string by ':' and convert the second part to u16
|
||||
let mut parts_iter = self.rsplitn(1, ':');
|
||||
let mut parts_iter = self.rsplitn(2, ':');
|
||||
let port_str = try_opt!(parts_iter.next(), "invalid socket address");
|
||||
let host = try_opt!(parts_iter.next(), "invalid socket address");
|
||||
let port: u16 = try_opt!(port_str.parse().ok(), "invalid port value");
|
||||
|
@ -415,7 +415,7 @@ fn split_file_at_dot(file: &OsStr) -> (Option<&OsStr>, Option<&OsStr>) {
|
||||
// contents of the encoding and (2) new &OsStr values are produced
|
||||
// only from ASCII-bounded slices of existing &OsStr values.
|
||||
|
||||
let mut iter = os_str_as_u8_slice(file).rsplitn(1, |b| *b == b'.');
|
||||
let mut iter = os_str_as_u8_slice(file).rsplitn(2, |b| *b == b'.');
|
||||
let after = iter.next();
|
||||
let before = iter.next();
|
||||
if before == Some(b"") {
|
||||
|
@ -409,7 +409,7 @@ pub fn env() -> Env {
|
||||
};
|
||||
|
||||
fn parse(input: &[u8]) -> (OsString, OsString) {
|
||||
let mut it = input.splitn(1, |b| *b == b'=');
|
||||
let mut it = input.splitn(2, |b| *b == b'=');
|
||||
let key = it.next().unwrap().to_vec();
|
||||
let default: &[u8] = &[];
|
||||
let val = it.next().unwrap_or(default).to_vec();
|
||||
|
Loading…
Reference in New Issue
Block a user