A flexible iterator for transforming an Iterator[A] into an Iterator[Seq[A]], with configurable sequence size, step, and strategy for dealing with elements which don't fit evenly.
Typical uses can be achieved via methods grouped and sliding.
Test two objects for inequality.
true if !(this == that), false otherwise.
Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.
a hash value consistent with ==
Concatenates this iterator with another.
the other iterator
a new iterator that first yields the values produced by this iterator followed by the values produced by iterator that.
Applies a binary operator to a start value and all elements of this traversable or iterator, going left to right.
Note: /: is alternate syntax for foldLeft; z /: xs is the same as xs foldLeft z.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = (5 /: a)(_+_) b: Int = 15 scala> val c = (5 /: a)((x,y) => x + y) c: Int = 15
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this traversable or iterator, going left to right with the start value z on the left:
op(...op(op(z, x_1), x_2), ..., x_n)
where x1, ..., xn are the elements of this traversable or iterator.
Applies a binary operator to all elements of this traversable or iterator and a start value, going right to left.
Note: :\ is alternate syntax for foldRight; xs :\ z is the same as xs foldRight z.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
Examples:
Note that the folding function used to compute b is equivalent to that used to compute c.
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = (a :\ 5)(_+_) b: Int = 15 scala> val c = (a :\ 5)((x,y) => x + y) c: Int = 15
the result type of the binary operator.
the start value
the binary operator
the result of inserting op between consecutive elements of this traversable or iterator, going right to left with the start value z on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn are the elements of this traversable or iterator.
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
true if the receiver object is equivalent to the argument; false otherwise.
Sends an abort signal to other workers.
Abort flag being true means that a worker can abort and produce whatever result, since its result will not affect the final result of computation. An example of operations using this are find, forall and exists methods.
Appends all elements of this traversable or iterator to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this traversable or iterator without any separator string.
Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> val h = a.addString(b) h: StringBuilder = 1234
the string builder to which elements are appended.
the string builder b to which elements were appended.
Appends all elements of this traversable or iterator to a string builder using a separator string. The written text consists of the string representations (w.r.t. the method toString) of all elements of this traversable or iterator, separated by the string sep.
Example:
scala> val a = List(1,2,3,4) a: List[Int] = List(1, 2, 3, 4) scala> val b = new StringBuilder() b: StringBuilder = scala> a.addString(b, ", ") res0: StringBuilder = 1, 2, 3, 4
the string builder to which elements are appended.
the separator string.
the string builder b to which elements were appended.
Appends all elements of this traversable or iterator to a string builder using start, end, and separator strings. The written text begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.
Example:
scala> val a = List(1,2,3,4)
a: List[Int] = List(1, 2, 3, 4)
scala> val b = new StringBuilder()
b: StringBuilder =
scala> a.addString(b , "List(" , ", " , ")")
res5: StringBuilder = List(1, 2, 3, 4)
the string builder to which elements are appended.
the starting string.
the separator string.
the ending string.
the string builder b to which elements were appended.
Aggregates the results of applying an operator to subsequent elements.
This is a more general form of fold and reduce. It is similar to foldLeft in that it doesn't require the result to be a supertype of the element type. In addition, it allows parallel collections to be processed in chunks, and then combines the intermediate results.
aggregate splits the traversable or iterator into partitions and processes each partition by sequentially applying seqop, starting with z (like foldLeft). Those intermediate results are then combined by using combop (like fold). The implementation of this operation may operate on an arbitrary number of collection partitions (even 1), so combop may be invoked an arbitrary number of times (even 0).
As an example, consider summing up the integer values of a list of chars. The initial value for the sum is 0. First, seqop transforms each input character to an Int and adds it to the sum (of the partition). Then, combop just needs to sum up the intermediate results of the partitions:
List('a', 'b', 'c').aggregate(0)({ (sum, ch) => sum + ch.toInt }, { (p1, p2) => p1 + p2 })
the type of accumulated results
the initial value for the accumulated result of the partition - this will typically be the neutral element for the seqop operator (e.g. Nil for list concatenation or 0 for summation) and may be evaluated more than once
an operator used to accumulate results within a partition
an associative operator used to combine results from different partitions
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException if the receiver object is not an instance of the erasure of type T0.
Creates a buffered iterator from this iterator.
a buffered iterator producing the same values as this iterator.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
a copy of the receiver object.
Creates an iterator by transforming values produced by this iterator with a partial function, dropping those values for which the partial function is not defined.
the partial function which filters and maps the iterator.
a new iterator which yields each value x produced by this iterator for which pf is defined the image pf(x).
(Changed in version 2.8.0) collect has changed. The previous behavior can be reproduced with toSeq.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Finds the first element of the traversable or iterator for which the given partial function is defined, and applies the partial function to it.
Note: may not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the partial function
an option value containing pf applied to the first value for which it is defined, or None if none exists.
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Tests whether this iterator contains a given value as an element.
Note: may not terminate for infinite iterators.
the element to test.
true if this iterator produces some value that is is equal (as determined by ==) to elem, false otherwise.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Copies selected values produced by this iterator to an array. Fills the given array xs starting at index start with at most len values produced by this iterator. Copying will stop once either the end of the current iterator is reached, or the end of the array is reached, or len elements have been copied.
Note: will not terminate for infinite iterators.
the array to fill.
the starting index.
the maximal number of elements to copy.
Copies the elements of this traversable or iterator to an array. Fills the given array xs with values of this traversable or iterator. Copying will stop once either the end of the current traversable or iterator is reached, or the end of the target array is reached.
Note: will not terminate for infinite iterators.
the array to fill.
Copies the elements of this traversable or iterator to an array. Fills the given array xs with values of this traversable or iterator, beginning at index start. Copying will stop once either the end of the current traversable or iterator is reached, or the end of the target array is reached.
Note: will not terminate for infinite iterators.
the array to fill.
the starting index.
Copies all elements of this traversable or iterator to a buffer.
Note: will not terminate for infinite-sized collections.
The buffer to which elements are copied.
Tests whether every element of this iterator relates to the corresponding element of another collection by satisfying a test predicate.
the type of the elements of that
the other collection
the test predicate, which relates elements from both collections
true if both collections have the same length and p(x, y) is true for all corresponding elements x of this iterator and y of that, otherwise false
Counts the number of elements in the traversable or iterator which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p.
Drop implemented as simple eager consumption.
the number of elements to drop
an iterator which produces all values of the current iterator, except it omits the first n values.
Skips longest sequence of elements of this iterator which satisfy given predicate p, and returns an iterator of the remaining elements.
the predicate used to skip elements.
an iterator consisting of the remaining elements
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Creates a copy of this iterator.
Creates two new iterators that both iterate over the same elements as this iterator (in the same order). The duplicate iterators are considered equal if they are positioned at the same element.
Given that most methods on iterators will make the original iterator unfit for further use, this methods provides a reliable way of calling multiple such methods on an iterator.
a pair of iterators
The implementation may allocate temporary storage for elements iterated by one iterator but not yet by the other.
,Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterators that were returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterators as well.
Tests whether the argument (that) is a reference to the receiver object (this).
The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:
x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
true if the argument is a reference to the receiver object; false otherwise.
The equality method for reference types. Default implementation delegates to eq.
See also equals in scala.Any.
true if the receiver object is equivalent to the argument; false otherwise.
Tests whether a predicate holds for some of the values produced by this iterator.
Note: may not terminate for infinite iterators.
the predicate used to test elements.
true if the given predicate p holds for some of the values produced by this iterator, otherwise false.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Returns an iterator over all the elements of this iterator that satisfy the predicate p. The order of the elements is preserved.
the predicate used to test values.
an iterator which produces those values of this iterator which satisfy the predicate p.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Creates an iterator over all the elements of this iterator which do not satisfy a predicate p.
the predicate used to test values.
an iterator which produces those values of this iterator which do not satisfy the predicate p.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.
not specified by SLS as a member of AnyRef
Finds the first value produced by the iterator satisfying a predicate, if any.
Note: may not terminate for infinite iterators.
the predicate used to test values.
an option value containing the first value produced by the iterator that satisfies predicate p, or None if none exists.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Creates a new iterator by applying a function to all values produced by this iterator and concatenating the results.
the function to apply on each element.
the iterator resulting from applying the given iterator-valued function f to each value produced by this iterator and concatenating the results.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Folds the elements of this traversable or iterator using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
Note: will not terminate for infinite iterators.
a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g., Nil for list concatenation, 0 for addition, or 1 for multiplication).
a binary operator that must be associative.
the result of applying the fold operator op between all the elements and z, or z if this traversable or iterator is empty.
Applies a binary operator to a start value and all elements of this traversable or iterator, going left to right.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this traversable or iterator, going left to right with the start value z on the left:
op(...op(z, x_1), x_2, ..., x_n)
where x1, ..., xn are the elements of this traversable or iterator. Returns z if this traversable or iterator is empty.
Applies a binary operator to all elements of this traversable or iterator and a start value, going right to left.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op between consecutive elements of this traversable or iterator, going right to left with the start value z on the right:
op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn are the elements of this traversable or iterator. Returns z if this traversable or iterator is empty.
Tests whether a predicate holds for all values produced by this iterator.
Note: may not terminate for infinite iterators.
the predicate used to test elements.
true if the given predicate p holds for all values produced by this iterator, otherwise false.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Applies a function f to all values produced by this iterator.
the function that is applied for its side-effect to every element. The result of function f is discarded.
Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).
Returns the runtime class representation of the object.
a class object corresponding to the runtime type of the receiver.
Returns an iterator which groups this iterator into fixed size blocks. Example usages:
// Returns List(List(1, 2, 3), List(4, 5, 6), List(7))) (1 to 7).iterator grouped 3 toList // Returns List(List(1, 2, 3), List(4, 5, 6)) (1 to 7).iterator grouped 3 withPartial false toList // Returns List(List(1, 2, 3), List(4, 5, 6), List(7, 20, 25) // Illustrating that withPadding's argument is by-name. val it2 = Iterator.iterate(20)(_ + 5) (1 to 7).iterator grouped 3 withPadding it2.next toList
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Tests whether this Iterator has a known size.
true for empty Iterators, false otherwise.
Reuse: The iterator remains valid for further use whatever result is returned.
Tests whether this iterator can provide another element.
true if a subsequent call to next will yield an element, false otherwise.
The hashCode method for reference types. See hashCode in scala.Any.
the hash code value for this object.
Returns the value of the index flag.
The index flag holds an integer which carries some operation-specific meaning. For instance, takeWhile operation sets the index flag to the position of the element where the predicate fails. Other workers may check this index against the indices they are working on and return if this index is smaller than their index. Examples of operations using this are takeWhile, dropWhile, span and indexOf.
the value of the index flag
Returns the index of the first occurrence of the specified object in this iterable object after or at some start index.
Note: may not terminate for infinite iterators.
element to search for.
the start index
the index >= from of the first occurrence of elem in the values produced by this iterator, or -1 if such an element does not exist until the end of the iterator is reached.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Returns the index of the first occurrence of the specified object in this iterable object.
Note: may not terminate for infinite iterators.
element to search for.
the index of the first occurrence of elem in the values produced by this iterator, or -1 if such an element does not exist until the end of the iterator is reached.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Returns the index of the first produced value satisfying a predicate, or -1, after or at some start index.
Note: may not terminate for infinite iterators.
the predicate to test values
the start index
the index >= from of the first produced value satisfying p, or -1 if such an element does not exist until the end of the iterator is reached.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Returns the index of the first produced value satisfying a predicate, or -1.
Note: may not terminate for infinite iterators.
the predicate to test values
the index of the first produced value satisfying p, or -1 if such an element does not exist until the end of the iterator is reached.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Checks whether an abort signal has been issued.
Abort flag being true means that a worker can abort and produce whatever result, since its result will not affect the final result of computation. An example of operations using this are find, forall and exists methods.
the state of the abort
Tests whether this iterator is empty.
true if hasNext is false, false otherwise.
Reuse: The iterator remains valid for further use whatever result is returned.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
true if the receiver object is an instance of erasure of type T0; false otherwise.
For most collections, this is a cheap operation. Exceptions can override this method.
Tests whether this Iterator can be repeatedly traversed.
false
Reuse: The iterator remains valid for further use whatever result is returned.
Returns the number of elements in this iterator.
Note: will not terminate for infinite iterators.
Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.
Creates a new iterator that maps all produced values of this iterator to new values using a transformation function.
the transformation function
a new iterator which transforms every value produced by this iterator by applying the function f to it.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Finds the largest element.
the largest element of this traversable or iterator.
UnsupportedOperationException if this traversable or iterator is empty.
Finds the first element which yields the largest value measured by function f.
The result type of the function f.
The measuring function.
the first element of this traversable or iterator with the largest value measured by function f.
UnsupportedOperationException if this traversable or iterator is empty.
Finds the smallest element.
the smallest element of this traversable or iterator
UnsupportedOperationException if this traversable or iterator is empty.
Finds the first element which yields the smallest value measured by function f.
The result type of the function f.
The measuring function.
the first element of this traversable or iterator with the smallest value measured by function f.
UnsupportedOperationException if this traversable or iterator is empty.
Displays all elements of this traversable or iterator in a string.
a string representation of this traversable or iterator. In the resulting string the string representations (w.r.t. the method toString) of all elements of this traversable or iterator follow each other without any separator string.
Displays all elements of this traversable or iterator in a string using a separator string.
the separator string.
a string representation of this traversable or iterator. In the resulting string the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this traversable or iterator in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this traversable or iterator. The resulting string begins with the string start and ends with the string end. Inside, the string representations (w.r.t. the method toString) of all elements of this traversable or iterator are separated by the string sep.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
Produces the next element of this iterator.
the next element of this iterator, if hasNext is true, undefined behavior otherwise.
Tests whether the traversable or iterator is not empty.
true if the traversable or iterator contains at least one element, false otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Appends an element value to this iterator until a given target length is reached.
the target length
the padding value
a new iterator consisting of producing all values of this iterator, followed by the minimal number of occurrences of elem so that the number of produced values is at least len.
Partitions this iterator in two iterators according to a predicate.
the predicate on which to partition
a pair of iterators: the iterator that satisfies the predicate p and the iterator that does not. The relative order of the elements in the resulting iterators is the same as in the original iterator.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterators that were returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterators as well.
Returns this iterator with patched values. Patching at negative indices is the same as patching starting at 0. Patching at indices at or larger than the length of the original iterator appends the patch to the end. If more values are replaced than actually exist, the excess is ignored.
The start index from which to patch
The iterator of patch values
The number of values in the original iterator that are replaced by the patch.
Reuse: After calling this method, one should discard the iterator it was called on, as well as the one passed as a parameter, and use only the iterator that was returned. Using the old iterators is undefined, subject to change, and may result in changes to the new iterator as well.
Multiplies up the elements of this collection.
the product of all elements in this traversable or iterator of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the traversable or iterator and as result type of product. Examples of such types are: Long, Float, Double, BigInt.
Reduces the elements of this traversable or iterator using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A binary operator that must be associative.
The result of applying reduce operator op between all the elements if the traversable or iterator is nonempty.
UnsupportedOperationException if this traversable or iterator is empty.
Applies a binary operator to all elements of this traversable or iterator, going left to right.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
the result of inserting op between consecutive elements of this traversable or iterator, going left to right:
op( op( ... op(x_1, x_2) ..., x_{n-1}), x_n)
where x1, ..., xn are the elements of this traversable or iterator.
UnsupportedOperationException if this traversable or iterator is empty.
Optionally applies a binary operator to all elements of this traversable or iterator, going left to right.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceLeft(op) if this traversable or iterator is nonempty, None otherwise.
Reduces the elements of this traversable or iterator, if any, using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
A type parameter for the binary operator, a supertype of A.
A binary operator that must be associative.
An option value containing result of applying reduce operator op between all the elements if the collection is nonempty, and None otherwise.
Applies a binary operator to all elements of this traversable or iterator, going right to left.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
the result of inserting op between consecutive elements of this traversable or iterator, going right to left:
op(x_1, op(x_2, ..., op(x_{n-1}, x_n)...))
where x1, ..., xn are the elements of this traversable or iterator.
UnsupportedOperationException if this traversable or iterator is empty.
Optionally applies a binary operator to all elements of this traversable or iterator, going right to left.
Note: will not terminate for infinite-sized collections.
Note: might return different results for different runs, unless the underlying collection type is ordered or the operator is associative and commutative.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceRight(op) if this traversable or iterator is nonempty, None otherwise.
The number of elements this iterator has yet to traverse. This method doesn't change the state of the iterator.
This method is used to provide size hints to builders and combiners, and to approximate positions of iterators within a data structure.
Note: This method may be implemented to return an upper bound on the number of elements in the iterator, instead of the exact number of elements to iterate. Parallel collections which have such iterators are called non-strict-splitter collections.
In that case, 2 considerations must be taken into account:
1) classes that inherit ParIterable must reimplement methods take, drop, slice, splitAt, copyToArray and all others using this information.
2) if an iterator provides an upper bound on the number of elements, then after splitting the sum of remaining values of split iterators must be less than or equal to this upper bound.
Tests if another iterator produces the same values as this one.
Note: will not terminate for infinite iterators.
the other iterator
true, if both iterators produce the same elements in the same order, false otherwise.
Reuse: After calling this method, one should discard the iterator it was called on, as well as the one passed as parameter. Using the old iterators is undefined and subject to change.
Produces a collection containing cumulative results of applying the operator going left to right, including the initial value.
Note: will not terminate for infinite iterators.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the elements in the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
iterator with intermediate results
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Produces a collection containing cumulative results of applying the operator going right to left. The head of the collection is the last cumulative result.
Note: will not terminate for infinite iterators.
Note: might return different results for different runs, unless the underlying collection type is ordered.
the type of the elements in the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
iterator with intermediate results
Iterator(1, 2, 3, 4).scanRight(0)(_ + _).toList == List(10, 9, 7, 4, 0)
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
A version of this collection with all of the operations implemented sequentially (i.e., in a single-threaded manner).
This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.
a sequential view of the collection.
Sets the value of the index flag.
The index flag holds an integer which carries some operation-specific meaning. For instance, takeWhile operation sets the index flag to the position of the element where the predicate fails. Other workers may check this index against the indices they are working on and return if this index is smaller than their index. Examples of operations using this are takeWhile, dropWhile, span and indexOf.
the value to which the index flag is set.
Sets the value of the index flag if argument is greater than current value. This method does this atomically.
The index flag holds an integer which carries some operation-specific meaning. For instance, takeWhile operation sets the index flag to the position of the element where the predicate fails. Other workers may check this index against the indices they are working on and return if this index is smaller than their index. Examples of operations using this are takeWhile, dropWhile, span and indexOf.
the value to which the index flag is set
Sets the value of the index flag if argument is lesser than current value. This method does this atomically.
The index flag holds an integer which carries some operation-specific meaning. For instance, takeWhile operation sets the index flag to the position of the element where the predicate fails. Other workers may check this index against the indices they are working on and return if this index is smaller than their index. Examples of operations using this are takeWhile, dropWhile, span and indexOf.
the value to which the index flag is set
A delegate that method calls are redirected to.
The size of this traversable or iterator.
Note: will not terminate for infinite-sized collections.
the number of elements in this traversable or iterator.
The size of this collection or iterator, if it can be cheaply computed
the number of elements in this collection or iterator, or -1 if the size cannot be determined cheaply
Creates an iterator returning an interval of the values produced by this iterator.
an iterator which advances this iterator past the first from elements using drop, and then takes until - from elements, using take.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Creates an optionally bounded slice, unbounded if until is negative.
Returns an iterator which presents a "sliding window" view of this iterator. The first argument is the window size, and the second argument step is how far to advance the window on each iteration. The step defaults to 1.
The default GroupedIterator can be configured to either pad a partial result to size size or suppress the partial result entirely.
Example usages:
// Returns List(List(1, 2, 3), List(2, 3, 4), List(3, 4, 5)) (1 to 5).iterator.sliding(3).toList // Returns List(List(1, 2, 3, 4), List(4, 5)) (1 to 5).iterator.sliding(4, 3).toList // Returns List(List(1, 2, 3, 4)) (1 to 5).iterator.sliding(4, 3).withPartial(false).toList // Returns List(List(1, 2, 3, 4), List(4, 5, 20, 25)) // Illustrating that withPadding's argument is by-name. val it2 = Iterator.iterate(20)(_ + 5) (1 to 5).iterator.sliding(4, 3).withPadding(it2.next).toList
An iterator producing Seq[B]s of size size, except the last element (which may be the only element) will be truncated if there are fewer than size elements remaining to be grouped. This behavior can be configured.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Splits this Iterator into a prefix/suffix pair according to a predicate.
the test predicate
a pair of Iterators consisting of the longest prefix of this whose elements all satisfy p, and the rest of the Iterator.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterators that were returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterators as well.
Splits the iterator into a sequence of disjunct views.
Returns a sequence of split iterators, each iterating over some subset of the elements in the collection. These subsets are disjoint and should be approximately equal in size. These subsets are not empty, unless the iterator is empty in which case this method returns a sequence with a single empty iterator. If the splitter has more than two elements, this method will return two or more splitters.
Implementors are advised to keep this partition relatively small - two splitters are already enough when partitioning the collection, although there may be a few more.
Note: this method actually invalidates the current splitter.
a sequence of disjunct iterators of the collection
Sums up the elements of this collection.
the sum of all elements in this traversable or iterator of numbers of type Int. Instead of Int, any other type T with an implicit Numeric[T] implementation can be used as element type of the traversable or iterator and as result type of sum. Examples of such types are: Long, Float, Double, BigInt.
A read only tag specific to the signalling object. It is used to give specific workers information on the part of the collection being operated on.
Selects first n values of this iterator.
the number of values to take
an iterator producing only the first n values of this iterator, or else the whole iterator, if it produces fewer than n values.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Takes longest prefix of values produced by this iterator that satisfy a predicate.
The predicate used to test elements.
An iterator returning the values produced by this iterator, until this iterator produces a value that does not satisfy the predicate p.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Converts this traversable or iterator into another by copying all elements.
Note: will not terminate for infinite iterators.
The collection type to build.
a new collection containing all elements of this traversable or iterator.
Converts this traversable or iterator to an array.
Note: will not terminate for infinite iterators.
an array containing all elements of this traversable or iterator. An ClassTag must be available for the element type of this traversable or iterator.
Uses the contents of this traversable or iterator to create a new mutable buffer.
Note: will not terminate for infinite-sized collections.
a buffer containing all elements of this traversable or iterator.
Converts this traversable or iterator to an indexed sequence.
Note: will not terminate for infinite-sized collections.
an indexed sequence containing all elements of this traversable or iterator.
Converts this traversable or iterator to an iterable collection. Note that the choice of target Iterable is lazy in this default implementation as this TraversableOnce may be lazy and unevaluated (i.e. it may be an iterator which is only traversable once).
Note: will not terminate for infinite-sized collections.
an Iterable containing all elements of this traversable or iterator.
Returns an Iterator over the elements in this traversable or iterator. Will return the same Iterator if this instance is already an Iterator.
Note: will not terminate for infinite iterators.
an Iterator containing all elements of this traversable or iterator.
Converts this traversable or iterator to a list.
Note: will not terminate for infinite-sized collections.
a list containing all elements of this traversable or iterator.
Converts this traversable or iterator to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.
Note: will not terminate for infinite iterators.
a map of type immutable.Map[T, U] containing all key/value pairs of type (T, U) of this traversable or iterator.
Converts this traversable or iterator to a sequence. As with toIterable, it's lazy in this default implementation, as this TraversableOnce may be lazy and unevaluated.
Note: will not terminate for infinite-sized collections.
a sequence containing all elements of this traversable or iterator.
Converts this traversable or iterator to a set.
Note: will not terminate for infinite-sized collections.
a set containing all elements of this traversable or iterator.
Converts this traversable or iterator to a stream.
a stream containing all elements of this traversable or iterator.
Converts this iterator to a string.
"<iterator>" whether or not the iterator is empty.
Converts this traversable or iterator to an unspecified Traversable. Will return the same collection if this instance is already Traversable.
Note: will not terminate for infinite iterators.
a Traversable containing all elements of this traversable or iterator.
Converts this traversable or iterator to a Vector.
Note: will not terminate for infinite-sized collections.
a vector containing all elements of this traversable or iterator.
Creates an iterator over all the elements of this iterator that satisfy the predicate p. The order of the elements is preserved.
Note: withFilter is the same as filter on iterators. It exists so that for-expressions with filters work over iterators.
the predicate used to test values.
an iterator which produces those values of this iterator which satisfy the predicate p.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
Creates an iterator formed from this iterator and another iterator by combining corresponding values in pairs. If one of the two iterators is longer than the other, its remaining elements are ignored.
The iterator providing the second half of each result pair
a new iterator containing pairs consisting of corresponding elements of this iterator and that. The number of elements returned by the new iterator is the minimum of the number of elements returned by this iterator and that.
Reuse: After calling this method, one should discard the iterator it was called on, as well as the one passed as a parameter, and use only the iterator that was returned. Using the old iterators is undefined, subject to change, and may result in changes to the new iterator as well.
Creates an iterator formed from this iterator and another iterator by combining corresponding elements in pairs. If one of the two iterators is shorter than the other, placeholder elements are used to extend the shorter iterator to the length of the longer.
iterator that may have a different length as the self iterator.
element thisElem is used to fill up the resulting iterator if the self iterator is shorter than that
element thatElem is used to fill up the resulting iterator if that is shorter than the self iterator
a new iterator containing pairs consisting of corresponding values of this iterator and that. The length of the returned iterator is the maximum of the lengths of this iterator and that. If this iterator is shorter than that, thisElem values are used to pad the result. If that is shorter than this iterator, thatElem values are used to pad the result.
Creates an iterator that pairs each element produced by this iterator with its index, counting from 0.
a new iterator containing pairs consisting of corresponding elements of this iterator and their indices.
Reuse: After calling this method, one should discard the iterator it was called on, and use only the iterator that was returned. Using the old iterator is undefined, subject to change, and may result in changes to the new iterator as well.
(appended: MonadOps[U]).filter(p)
(appended: MonadOps[U]).flatMap(f)
(appended: MonadOps[U]).map(f)
(appended: MonadOps[U]).withFilter(p)
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.12.9/scala/collection/parallel/IterableSplitter$Appended.html