struct StrideThrough<Element : Strideable>
Inheritance |
SequenceType, _Reflectable
View Protocol Hierarchy →
|
---|---|
Associated Types | |
Import | import Swift |
Instance Variables
A sequence containing the same elements as a Base
sequence,
but on which some operations such as map
and filter
are
implemented lazily.
See Also: LazySequenceType
, LazySequence
Declaration
var lazy: LazySequence<StrideThrough<Element>> { get }
Declared In
SequenceType
Instance Methods
Returns true
iff an element in self
satisfies predicate
.
Declaration
func contains(@noescape predicate: (Strideable) throws -> Bool) rethrows -> Bool
Declared In
SequenceType
Returns a subsequence containing all but the first element.
Complexity: O(1)
Declaration
func dropFirst() -> StrideThrough<Element>.SubSequence
Declared In
SequenceType
Returns a subsequence containing all but the first n
elements.
Requires: n >= 0
Complexity: O(n
)
Declaration
func dropFirst(n: Int) -> AnySequence<Strideable>
Declared In
SequenceType
Returns a subsequence containing all but the last element.
Requires: self
is a finite sequence.
Complexity: O(self.count
)
Declaration
func dropLast() -> StrideThrough<Element>.SubSequence
Declared In
SequenceType
Returns a subsequence containing all but the last n
elements.
Requires: self
is a finite collection.
Requires: n >= 0
Complexity: O(self.count
)
Declaration
func dropLast(n: Int) -> AnySequence<Strideable>
Declared In
SequenceType
Returns true
iff self
and other
contain the same elements in the
same order.
Declaration
func elementsEqual<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool
Declared In
SequenceType
Returns true
iff self
and other
contain equivalent elements, using
isEquivalent
as the equivalence test.
Requires: isEquivalent
is an
equivalence relation.
Declaration
func elementsEqual<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence, @noescape isEquivalent: (Strideable, Strideable) throws -> Bool) rethrows -> Bool
Declared In
SequenceType
Returns a lazy SequenceType
containing pairs (n, x), where
ns are consecutive Int
s starting at zero, and xs are
the elements of base
:
> for (n, c) in "Swift".characters.enumerate() {
print("\(n): '\(c)'")
}
0: 'S'
1: 'w'
2: 'i'
3: 'f'
4: 't'
Declaration
func enumerate() -> EnumerateSequence<StrideThrough<Element>>
Declared In
SequenceType
Returns an Array
containing the elements of self
,
in order, that satisfy the predicate includeElement
.
Declaration
func filter(@noescape includeElement: (Strideable) throws -> Bool) rethrows -> [Strideable]
Declared In
SequenceType
Returns an Array
containing the non-nil results of mapping
transform
over self
.
Complexity: O(M + N), where M is the length of self
and N is the length of the result.
Declaration
func flatMap<T>(@noescape transform: (Strideable) throws -> T?) rethrows -> [T]
Declared In
SequenceType
Returns an Array
containing the concatenated results of mapping
transform
over self
.
s.flatMap(transform)
is equivalent to
Array(s.map(transform).flatten())
Complexity: O(M + N), where M is the length of self
and N is the length of the result.
Declaration
func flatMap<S : SequenceType>(transform: (Strideable) throws -> S) rethrows -> [S.Generator.Element]
Declared In
SequenceType
Call body
on each element in self
in the same order as a
for-in loop.
sequence.forEach {
// body code
}
is similar to:
for element in sequence {
// body code
}
Note: You cannot use the break
or continue
statement to exit the
current call of the body
closure or skip subsequent calls.
Note: Using the return
statement in the body
closure will only
exit from the current call to body
, not any outer scope, and won't
skip subsequent calls.
Complexity: O(self.count
)
Declaration
func forEach(@noescape body: (Strideable) throws -> Void) rethrows
Declared In
SequenceType
Returns a generator over the elements of this sequence.
Complexity: O(1).
Declaration
func generate() -> StrideThroughGenerator<Element>
Returns true
iff self
precedes other
in a lexicographical
("dictionary") ordering, using "<" as the comparison between elements.
Note: This method implements the mathematical notion of lexicographical
ordering, which has no connection to Unicode. If you are sorting strings
to present to the end-user, you should use String
APIs that perform
localized comparison.
Declaration
func lexicographicalCompare<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool
Declared In
SequenceType
Returns true
iff self
precedes other
in a lexicographical
("dictionary") ordering, using isOrderedBefore
as the comparison
between elements.
Note: This method implements the mathematical notion of lexicographical
ordering, which has no connection to Unicode. If you are sorting strings
to present to the end-user, you should use String
APIs that perform
localized comparison.
Requires: isOrderedBefore
is a
strict weak ordering
over the elements of self
and other
.
Declaration
func lexicographicalCompare<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence, @noescape isOrderedBefore: (Strideable, Strideable) throws -> Bool) rethrows -> Bool
Declared In
SequenceType
Returns an Array
containing the results of mapping transform
over self
.
Complexity: O(N).
Declaration
func map<T>(@noescape transform: (Strideable) throws -> T) rethrows -> [T]
Declared In
SequenceType
Returns the maximum element in self
or nil
if the sequence is empty.
Complexity: O(elements.count
).
Declaration
func maxElement() -> Strideable?
Declared In
SequenceType
Returns the maximum element in self
or nil
if the sequence is empty.
Complexity: O(elements.count
).
Requires: isOrderedBefore
is a
strict weak ordering
over self
.
Declaration
func maxElement(@noescape isOrderedBefore: (Strideable, Strideable) throws -> Bool) rethrows -> Strideable?
Declared In
SequenceType
Returns the minimum element in self
or nil
if the sequence is empty.
Complexity: O(elements.count
).
Declaration
func minElement() -> Strideable?
Declared In
SequenceType
Returns the minimum element in self
or nil
if the sequence is empty.
Complexity: O(elements.count
).
Requires: isOrderedBefore
is a
strict weak ordering
over self
.
Declaration
func minElement(@noescape isOrderedBefore: (Strideable, Strideable) throws -> Bool) rethrows -> Strideable?
Declared In
SequenceType
Returns a subsequence, up to maxLength
in length, containing the
initial elements.
If maxLength
exceeds self.count
, the result contains all
the elements of self
.
Requires: maxLength >= 0
Declaration
func prefix(maxLength: Int) -> AnySequence<Strideable>
Declared In
SequenceType
Returns the result of repeatedly calling combine
with an
accumulated value initialized to initial
and each element of
self
, in turn, i.e. return
combine(combine(...combine(combine(initial, self[0]),
self[1]),...self[count-2]), self[count-1])
.
Declaration
func reduce<T>(initial: T, @noescape combine: (T, Strideable) throws -> T) rethrows -> T
Declared In
SequenceType
Returns an Array
containing the elements of self
in reverse
order.
Complexity: O(N), where N is the length of self
.
Declaration
func reverse() -> [Strideable]
Declared In
SequenceType
Returns an Array
containing the sorted elements of source
.
The sorting algorithm is not stable (can change the relative order of elements that compare equal).
Requires: The less-than operator (func <
) defined in
the Comparable
conformance is a
strict weak ordering
over the elements in self
.
Declaration
func sort() -> [Strideable]
Declared In
SequenceType
Returns an Array
containing the sorted elements of source
according to isOrderedBefore
.
The sorting algorithm is not stable (can change the relative order of
elements for which isOrderedBefore
does not establish an order).
Requires: isOrderedBefore
is a
strict weak ordering
over the elements in self
.
Declaration
func sort(@noescape isOrderedBefore: (Strideable, Strideable) -> Bool) -> [Strideable]
Declared In
SequenceType
Returns the maximal SubSequence
s of self
, in order, that
don't contain elements satisfying the predicate isSeparator
.
maxSplit
: The maximum number of SubSequence
s to
return, minus 1.
If maxSplit + 1
SubSequence
s are returned, the last one is
a suffix of self
containing the remaining elements.
The default value is Int.max
.
allowEmptySubsequences
: If true
, an empty SubSequence
is produced in the result for each pair of consecutive elements
satisfying isSeparator
.
The default value is false
.
Requires: maxSplit >= 0
Declaration
func split(maxSplit: Int = default, allowEmptySlices: Bool = default, @noescape isSeparator: (Strideable) throws -> Bool) rethrows -> [AnySequence<Strideable>]
Declared In
SequenceType
Returns the maximal SubSequence
s of self
, in order, around elements
equatable to separator
.
maxSplit
: The maximum number of SubSequence
s to
return, minus 1.
If maxSplit + 1
SubSequence
s are returned, the last one is
a suffix of self
containing the remaining elements.
The default value is Int.max
.
allowEmptySubsequences
: If true
, an empty SubSequence
is produced in the result for each pair of consecutive elements
satisfying isSeparator
.
The default value is false
.
Requires: maxSplit >= 0
Declaration
func split(separator: Strideable, maxSplit: Int = default, allowEmptySlices: Bool = default) -> [AnySequence<Strideable>]
Declared In
SequenceType
Returns true
iff the initial elements of self
are equal to prefix
.
Returns true
if other
is empty.
Declaration
func startsWith<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool
Declared In
SequenceType
Returns true
iff self
begins with elements equivalent to those of
other
, using isEquivalent
as the equivalence test. Returns true
if
other
is empty.
Requires: isEquivalent
is an
equivalence relation.
Declaration
func startsWith<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence, @noescape isEquivalent: (Strideable, Strideable) throws -> Bool) rethrows -> Bool
Declared In
SequenceType
Returns a slice, up to maxLength
in length, containing the
final elements of s
.
If maxLength
exceeds s.count
, the result contains all
the elements of s
.
Requires: self
is a finite sequence.
Requires: maxLength >= 0
Declaration
func suffix(maxLength: Int) -> AnySequence<Strideable>
Declared In
SequenceType
Returns a value less than or equal to the number of elements in
self
, nondestructively.
Complexity: O(N).
Declaration
func underestimateCount() -> Int
Declared In
SequenceType
A
SequenceType
of values formed by striding over a closed interval.