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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<AnyGenerator<Element>> { get }

Declared In

SequenceType

Return true iff an element in self satisfies predicate.

Declaration

func contains(@noescape predicate: (Generator.Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType

Returns a subsequence containing all but the first element.

Requires: n >= 0 Complexity: O(n)

Declaration

func dropFirst() -> Slice<AnyGenerator<Element>>

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<Generator.Element>

Declared In

SequenceType

Returns a subsequence containing all but the last element.

Requires: self is a finite sequence. Requires: n >= 0 Complexity: O(self.count)

Declaration

func dropLast() -> Slice<AnyGenerator<Element>>

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<Generator.Element>

Declared In

SequenceType

Return 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: (Generator.Element, Generator.Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType

Return a lazy SequenceType containing pairs (n, x), where ns are consecutive Ints 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<AnyGenerator<Element>>

Declared In

SequenceType

Return an Array containing the elements of self, in order, that satisfy the predicate includeElement.

Declaration

func filter(@noescape includeElement: (Generator.Element) throws -> Bool) rethrows -> [Generator.Element]

Declared In

SequenceType

Return 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: (Generator.Element) throws -> T?) rethrows -> [T]

Declared In

SequenceType

Return 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: (Generator.Element) 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: (Generator.Element) throws -> ()) rethrows

Declared In

SequenceType

Return 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: (Generator.Element, Generator.Element) throws -> Bool) rethrows -> Bool

Declared In

SequenceType

Return an Array containing the results of mapping transform over self.

Complexity: O(N).

Declaration

func map<T>(@noescape transform: (Generator.Element) throws -> T) rethrows -> [T]

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: (Generator.Element, Generator.Element) throws -> Bool) rethrows -> Generator.Element?

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: (Generator.Element, Generator.Element) throws -> Bool) rethrows -> Generator.Element?

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<Generator.Element>

Declared In

SequenceType

Return 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, Generator.Element) throws -> T) rethrows -> T

Declared In

SequenceType

Return an Array containing the elements of self in reverse order.

Complexity: O(N), where N is the length of self.

Declaration

func reverse() -> [Generator.Element]

Declared In

SequenceType

Return 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: (Generator.Element, Generator.Element) -> Bool) -> [Generator.Element]

Declared In

SequenceType

Returns the maximal SubSequences of self, in order, that don't contain elements satisfying the predicate isSeparator.

maxSplit: The maximum number of SubSequences to return, minus 1. If maxSplit + 1 SubSequences 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: (Generator.Element) throws -> Bool) rethrows -> [AnySequence<Generator.Element>]

Declared In

SequenceType

Return true iff self begins with elements equivalent to those of other, using isEquivalent as the equivalence test. Return 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: (Generator.Element, Generator.Element) 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<Generator.Element>

Declared In

SequenceType

Return a value less than or equal to the number of elements in self, nondestructively.

Complexity: O(N).

Declaration

func underestimateCount() -> Int

Declared In

SequenceType

Return a generator over the elements of this sequence.

Complexity: O(1).

Declaration

func generate() -> AnyGenerator<Element>

Declared In

SequenceType

Return 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 the maximum element in self or nil if the sequence is empty.

Complexity: O(elements.count).

Declaration

func maxElement() -> Generator.Element?

Declared In

SequenceType

Returns the minimum element in self or nil if the sequence is empty.

Complexity: O(elements.count).

Declaration

func minElement() -> Generator.Element?

Declared In

SequenceType

Return 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() -> [Generator.Element]

Declared In

SequenceType

Return true iff element is in self.

Declaration

func contains(element: Generator.Element) -> Bool

Declared In

SequenceType

Return 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 the maximal SubSequences of self, in order, around elements equatable to separator.

maxSplit: The maximum number of SubSequences to return, minus 1. If maxSplit + 1 SubSequences 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: Generator.Element, maxSplit: Int = default, allowEmptySlices: Bool = default) -> [AnySequence<Generator.Element>]

Declared In

SequenceType

Return true iff the the initial elements of self are equal to prefix. Return true if other is empty.

Declaration

func startsWith<OtherSequence : SequenceType where OtherSequence.Generator.Element == Generator.Element>(other: OtherSequence) -> Bool

Declared In

SequenceType

A concatenation of the elements of self.

Declaration

func flatten() -> FlattenSequence<AnyGenerator<Element>>

Declared In

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<AnyGenerator<Element>>

Declared In

SequenceType

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

SequenceType