protocolSequenceType
| Inheritance | View Protocol Hierarchy → |
|---|---|
| Associated Types |
A type that provides the sequence's iteration interface and encapsulates its iteration state.
A type that represents a subsequence of some of the elements. |
| Import |
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Instance Methods
Returns a subsequence containing all but the first n elements.
Requires: n >= 0
Complexity: O(n)
Declaration
funcdropFirst(n:Int) ->Self.SubSequence
Returns a subsequence containing all but the last n elements.
Requires: self is a finite sequence.
Requires: n >= 0
Complexity: O(self.count)
Declaration
funcdropLast(n:Int) ->Self.SubSequence
Return an Array containing the elements of self,
in order, that satisfy the predicate includeElement.
Declaration
funcfilter(@noescapeincludeElement: (Self.Generator.Element)throws->Bool)rethrows->[Self.Generator.Element]
Call body on each element in self in the same order as a
for-in loop.
sequence.forEach{// body code}
is similar to:
forelementinsequence{// 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
funcforEach(@noescapebody: (Self.Generator.Element)throws->())rethrows
Return a generator over the elements of this sequence.
Complexity: O(1).
Declaration
funcgenerate() ->Self.Generator
Return an Array containing the results of mapping transform
over self.
Complexity: O(N).
Declaration
funcmap<T>(@noescapetransform: (Self.Generator.Element)throws->T)rethrows->[T]
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
funcprefix(maxLength:Int) ->Self.SubSequence
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
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
funcsuffix(maxLength:Int) ->Self.SubSequence
Return a value less than or equal to the number of elements in
self, nondestructively.
Complexity: O(N).
Declaration
funcunderestimateCount() ->Int
Default Implementations
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
varlazy:LazySequence<Self>{get}
Returns a subsequence containing all but the first element.
Requires: n >= 0
Complexity: O(n)
Declaration
funcdropFirst() ->Self.SubSequence
Returns a subsequence containing all but the first n elements.
Requires: n >= 0
Complexity: O(n)
Declaration
funcdropFirst(n:Int) ->AnySequence<Self.Generator.Element>
Returns a subsequence containing all but the last element.
Requires: self is a finite sequence.
Requires: n >= 0
Complexity: O(self.count)
Declaration
funcdropLast() ->Self.SubSequence
Returns a subsequence containing all but the last n elements.
Requires: self is a finite collection.
Requires: n >= 0
Complexity: O(self.count)
Declaration
funcdropLast(n:Int) ->AnySequence<Self.Generator.Element>
Return true iff self and other contain equivalent elements, using
isEquivalent as the equivalence test.
Requires: isEquivalent is an
equivalence relation.
Declaration
funcelementsEqual<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence, @noescapeisEquivalent: (Self.Generator.Element,Self.Generator.Element)throws->Bool)rethrows->Bool
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() {("\(n): '\(c)'")}0: 'S'1: 'w'2: 'i'3: 'f'4: 't'
Declaration
funcenumerate() ->EnumerateSequence<Self>
Return an Array containing the elements of self,
in order, that satisfy the predicate includeElement.
Declaration
funcfilter(@noescapeincludeElement: (Self.Generator.Element)throws->Bool)rethrows->[Self.Generator.Element]
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
funcflatMap<T>(@noescapetransform: (Self.Generator.Element)throws->T?)rethrows->[T]
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
funcflatMap<S:SequenceType>(transform: (Self.Generator.Element)throws->S)rethrows->[S.Generator.Element]
Call body on each element in self in the same order as a
for-in loop.
sequence.forEach{// body code}
is similar to:
forelementinsequence{// 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
funcforEach(@noescapebody: (Self.Generator.Element)throws->())rethrows
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
funclexicographicalCompare<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence, @noescapeisOrderedBefore: (Self.Generator.Element,Self.Generator.Element)throws->Bool)rethrows->Bool
Return an Array containing the results of mapping transform
over self.
Complexity: O(N).
Declaration
funcmap<T>(@noescapetransform: (Self.Generator.Element)throws->T)rethrows->[T]
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
funcmaxElement(@noescapeisOrderedBefore: (Self.Generator.Element,Self.Generator.Element)throws->Bool)rethrows->Self.Generator.Element?
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
funcminElement(@noescapeisOrderedBefore: (Self.Generator.Element,Self.Generator.Element)throws->Bool)rethrows->Self.Generator.Element?
Declaration
funcprefix(maxLength:Int) ->AnySequence<Self.Generator.Element>
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
funcreduce<T>(initial:T, @noescapecombine: (T,Self.Generator.Element)throws->T)rethrows->T
Return an Array containing the elements of self in reverse
order.
Complexity: O(N), where N is the length of self.
Declaration
funcreverse() ->[Self.Generator.Element]
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
funcsort(@noescapeisOrderedBefore: (Self.Generator.Element,Self.Generator.Element) ->Bool) ->[Self.Generator.Element]
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
funcsplit(maxSplit:Int=default,allowEmptySlices:Bool=default, @noescapeisSeparator: (Self.Generator.Element)throws->Bool)rethrows->[AnySequence<Self.Generator.Element>]
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
funcstartsWith<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence, @noescapeisEquivalent: (Self.Generator.Element,Self.Generator.Element)throws->Bool)rethrows->Bool
Declaration
funcsuffix(maxLength:Int) ->AnySequence<Self.Generator.Element>
Return a value less than or equal to the number of elements in
self, nondestructively.
Complexity: O(N).
Declaration
funcunderestimateCount() ->Int
Where Generator == Self, Self : GeneratorType
Declaration
funcgenerate() ->Self
Where Generator.Element : Comparable
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
funclexicographicalCompare<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence) ->Bool
Returns the maximum element in self or nil if the sequence is empty.
Complexity: O(elements.count).
Declaration
funcmaxElement() ->Self.Generator.Element?
Returns the minimum element in self or nil if the sequence is empty.
Complexity: O(elements.count).
Declaration
funcminElement() ->Self.Generator.Element?
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
funcsort() ->[Self.Generator.Element]
Where Generator.Element : Equatable
Return true iff element is in self.
Declaration
funccontains(element:Self.Generator.Element) ->Bool
Return true iff self and other contain the same elements in the
same order.
Declaration
funcelementsEqual<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence) ->Bool
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
funcsplit(separator:Self.Generator.Element,maxSplit:Int=default,allowEmptySlices:Bool=default) ->[AnySequence<Self.Generator.Element>]
Return true iff the the initial elements of self are equal to prefix.
Return true if other is empty.
Declaration
funcstartsWith<OtherSequence:SequenceTypewhereOtherSequence.Generator.Element==Generator.Element>(other:OtherSequence) ->Bool
Where Generator.Element : 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
funcjoinWithSeparator<Separator:SequenceTypewhereSeparator.Generator.Element==Generator.Element.Generator.Element>(separator:Separator) ->JoinSequence<Self>
Where Generator.Element == String
Where Self : _SequenceWrapperType, Generator == Base.Generator
Declaration
funcfilter(@noescapeincludeElement: (Self.Generator.Element)throws->Bool)rethrows->[Self.Generator.Element]
Return a generator over the elements of this sequence.
Complexity: O(1).
Declaration
funcgenerate() ->Self.Generator
Declaration
funcmap<T>(@noescapetransform: (Self.Generator.Element)throws->T)rethrows->[T]
Declaration
funcunderestimateCount() ->Int
A type that can be iterated with a
for...inloop.SequenceTypemakes no requirement on conforming types regarding whether they will be destructively "consumed" by iteration. To ensure non-destructive iteration, constrain your sequence toCollectionType.As a consequence, it is not possible to run multiple
forloops on a sequence to "resume" iteration:SequenceTypemakes no requirement about the behavior in that case. It is not correct to assume that a sequence will either be "consumable" and will resume iteration, or that a sequence is a collection and will restart iteration from the first element. A conforming sequence that is not a collection is allowed to produce an arbitrary sequence of elements from the second generator.