struct Range<Element : ForwardIndexType>
Inheritance |
CollectionType, CustomDebugStringConvertible, CustomStringConvertible, Equatable, Indexable, SequenceType, _Reflectable
View Protocol Hierarchy →
|
---|---|
Associated Types | |
Import | import Swift |
Initializers
Construct a range with startIndex == start
and endIndex ==
end
.
Deprecated: it will be removed in Swift 3. Use the '..<' operator..
Declaration
init(start: Element, end: Element)
Instance Variables
Returns the number of elements.
Complexity: O(1) if Index
conforms to RandomAccessIndexType
;
O(N) otherwise.
Declaration
var count: Element.Distance { get }
Declared In
CollectionType
A textual representation of self
, suitable for debugging.
Declaration
var debugDescription: String { get }
A textual representation of self
.
Declaration
var description: String { get }
The range's upper bound.
endIndex
is not a valid argument to subscript
, and is always
reachable from startIndex
by zero or more applications of
successor()
.
Declaration
var endIndex: Element { get set }
Returns the first element of self
, or nil
if self
is empty.
Complexity: O(1)
Declaration
var first: Element? { get }
Declared In
CollectionType
Returns the range of valid index values.
The result's endIndex
is the same as that of self
. Because
Range
is half-open, iterating the values of the result produces
all valid subscript arguments for self
, omitting its endIndex
.
Declaration
var indices: Range<Element> { get }
Declared In
CollectionType
Returns true
iff self
is empty.
Complexity: O(1)
Declaration
var isEmpty: Bool { get }
Declared In
CollectionType
A collection with contents identical to self
, but on which
normally-eager operations such as map
and filter
are
implemented lazily.
See Also: LazySequenceType
, LazyCollectionType
.
Declaration
var lazy: LazyCollection<Range<Element>> { get }
Declared In
CollectionType
The range's lower bound.
Identical to endIndex
in an empty range.
Declaration
var startIndex: Element { get set }
Subscripts
Access the element at position
.
Requires: position
is a valid position in self
and
position != endIndex
.
Declaration
subscript(position: Element) -> Element { get }
Declaration
subscript(_: Element._DisabledRangeIndex) -> Element { get }
Returns a collection representing a contiguous sub-range of
self
's elements.
Complexity: O(1)
Declaration
subscript(bounds: Range<Element>) -> Slice<Range<Element>> { get }
Declared In
CollectionType
Instance Methods
Returns true
iff an element in self
satisfies predicate
.
Declaration
func contains(@noescape predicate: (Element) throws -> Bool) rethrows -> Bool
Declared In
CollectionType
, SequenceType
Returns a subsequence containing all but the first element.
Complexity: O(1)
Declaration
func dropFirst() -> Slice<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns a subsequence containing all but the first n
elements.
Requires: n >= 0
Complexity: O(n
)
Declaration
func dropFirst(n: Int) -> Slice<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns a subsequence containing all but the last element.
Requires: self
is a finite sequence.
Complexity: O(self.count
)
Declaration
func dropLast() -> Slice<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns a subsequence containing all but the last n
elements.
Requires: n >= 0
Complexity: O(self.count
)
Declaration
func dropLast(n: Int) -> Slice<Range<Element>>
Declared In
CollectionType
, 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
CollectionType
, 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: (Element, Element) throws -> Bool) rethrows -> Bool
Declared In
CollectionType
, 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<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns an Array
containing the elements of self
,
in order, that satisfy the predicate includeElement
.
Declaration
func filter(@noescape includeElement: (Element) throws -> Bool) rethrows -> [Element]
Declared In
CollectionType
, 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: (Element) throws -> T?) rethrows -> [T]
Declared In
CollectionType
, 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: (Element) throws -> S) rethrows -> [S.Generator.Element]
Declared In
CollectionType
, 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: (Element) throws -> Void) rethrows
Declared In
CollectionType
, SequenceType
Returns a generator over the elements of this sequence.
Complexity: O(1).
Declaration
func generate() -> RangeGenerator<Element>
Returns the first index where predicate
returns true
for the
corresponding value, or nil
if such value is not found.
Complexity: O(self.count
).
Declaration
func indexOf(@noescape predicate: (Element) throws -> Bool) rethrows -> Element?
Declared In
CollectionType
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: (Element, Element) throws -> Bool) rethrows -> Bool
Declared In
CollectionType
, SequenceType
Returns an Array
containing the results of mapping transform
over self
.
Complexity: O(N).
Declaration
func map<T>(@noescape transform: (Element) throws -> T) rethrows -> [T]
Declared In
CollectionType
, 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: (Element, Element) throws -> Bool) rethrows -> Element?
Declared In
CollectionType
, 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: (Element, Element) throws -> Bool) rethrows -> Element?
Declared In
CollectionType
, 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
Complexity: O(maxLength
)
Declaration
func prefix(maxLength: Int) -> Slice<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns prefixUpTo(position.successor())
Complexity: O(1)
Declaration
func prefixThrough(position: Element) -> Slice<Range<Element>>
Declared In
CollectionType
Returns self[startIndex..<end]
Complexity: O(1)
Declaration
func prefixUpTo(end: Element) -> Slice<Range<Element>>
Declared In
CollectionType
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, Element) throws -> T) rethrows -> T
Declared In
CollectionType
, 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() -> [Element]
Declared In
CollectionType
, 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: (Element, Element) -> Bool) -> [Element]
Declared In
CollectionType
, 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: (Element) throws -> Bool) rethrows -> [Slice<Range<Element>>]
Declared In
CollectionType
, SequenceType
Returns the maximal SubSequence
s of self
, in order, around a
separator
element.
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: Element, maxSplit: Int = default, allowEmptySlices: Bool = default) -> [Slice<Range<Element>>]
Declared In
CollectionType
, 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
CollectionType
, 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: (Element, Element) throws -> Bool) rethrows -> Bool
Declared In
CollectionType
, 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: maxLength >= 0
Complexity: O(self.count
)
Declaration
func suffix(maxLength: Int) -> Slice<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns self[start..<endIndex]
Complexity: O(1)
Declaration
func suffixFrom(start: Element) -> Slice<Range<Element>>
Declared In
CollectionType
Returns a value less than or equal to the number of elements in
self
, nondestructively.
Complexity: O(N).
Declaration
func underestimateCount() -> Int
Declared In
CollectionType
, SequenceType
Conditionally Inherited Items
The initializers, methods, and properties listed below may be available on this type under certain conditions (such as methods that are available on Array
when its elements are Equatable
) or may not ever be available if that determination is beyond SwiftDoc.org's capabilities. Please open an issue on GitHub if you see something out of place!
Where Generator.Element : CollectionType
A concatenation of the elements of self
.
Declaration
func flatten() -> FlattenCollection<Range<Element>>
Declared In
CollectionType
Where Generator.Element : CollectionType, Index : BidirectionalIndexType, Generator.Element.Index : BidirectionalIndexType
A concatenation of the elements of self
.
Declaration
func flatten() -> FlattenBidirectionalCollection<Range<Element>>
Declared In
CollectionType
Where Generator.Element : Comparable
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
CollectionType
, SequenceType
Returns the maximum element in self
or nil
if the sequence is empty.
Complexity: O(elements.count
).
Declaration
func maxElement() -> Element?
Declared In
CollectionType
, SequenceType
Returns the minimum element in self
or nil
if the sequence is empty.
Complexity: O(elements.count
).
Declaration
func minElement() -> Element?
Declared In
CollectionType
, 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() -> [Element]
Declared In
CollectionType
, SequenceType
Where Generator.Element : SequenceType
A concatenation of the elements of self
.
Declaration
func flatten() -> FlattenSequence<Range<Element>>
Declared In
CollectionType
, SequenceType
Returns a view, whose elements are the result of interposing a given
separator
between the elements of the sequence self
.
For example,
[[1, 2, 3], [4, 5, 6], [7, 8, 9]].joinWithSeparator([-1, -2])
yields [1, 2, 3, -1, -2, 4, 5, 6, -1, -2, 7, 8, 9]
.
Declaration
func joinWithSeparator<Separator : SequenceType where Separator.Generator.Element == Generator.Element.Generator.Element>(separator: Separator) -> JoinSequence<Range<Element>>
Declared In
CollectionType
, SequenceType
Where Generator.Element == String
Interpose the separator
between elements of self
, then concatenate
the result. For example:
["foo", "bar", "baz"].joinWithSeparator("-|-") // "foo-|-bar-|-baz"
Declaration
func joinWithSeparator(separator: String) -> String
Declared In
CollectionType
, SequenceType
Where Index : BidirectionalIndexType
Returns a subsequence containing all but the last n
elements.
Requires: n >= 0
Complexity: O(n
)
Declaration
func dropLast(n: Int) -> Slice<Range<Element>>
Declared In
CollectionType
Returns the elements of self
in reverse order.
Complexity: O(1)
Declaration
func reverse() -> ReverseCollection<Range<Element>>
Declared In
CollectionType
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: maxLength >= 0
Complexity: O(maxLength
)
Declaration
func suffix(maxLength: Int) -> Slice<Range<Element>>
Declared In
CollectionType
Where Index : RandomAccessIndexType
Returns the elements of self
in reverse order.
Complexity: O(1)
Declaration
func reverse() -> ReverseRandomAccessCollection<Range<Element>>
Declared In
CollectionType
A collection of consecutive discrete index values.
Element
: Is both the element type and the index type of the collection.Like other collections, a range containing one element has an
endIndex
that is the successor of itsstartIndex
; and an empty range hasstartIndex == endIndex
.Axiom: for any
Range
r
,r[i] == i
.Therefore, if
Element
has a maximal value, it can serve as anendIndex
, but can never be contained in aRange<Element>
.It also follows from the axiom above that
(-99..<100)[0] == 0
. To prevent confusion (because some expect the result to be-99
), in a context whereElement
is known to be an integer type, subscripting withElement
is a compile-time error:However, subscripting that range still works in a generic context: