Set

Creates a new set with an additional element, unless the element is already present.

Creates a new set with a given element removed from this set.

Tests if some element is contained in this set.

Test two objects for inequality.

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.

Computes the intersection between this set and another set.

Note: Same as intersect.

The difference of this set and another set.

Note: Same as diff.

Creates a new set with additional elements.

This method takes two or more elements to be added. Another overloaded variant of this method handles the case where a single element is added.

Creates a new set by adding all elements contained in another collection to this set.

Returns a new set containing the elements from the left hand operand followed by the elements from the right hand operand. The element type of the set is the most specific superclass encompassing the element types of the two operands.

Example:

scala> val a = LinkedList(1)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1)

scala> val b = LinkedList(2)
b: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val c = a ++ b
c: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

scala> val d = LinkedList('a')
d: scala.collection.mutable.LinkedList[Char] = LinkedList(a)

scala> val e = c ++ d
e: scala.collection.mutable.LinkedList[AnyVal] = LinkedList(1, 2, a)

As with ++, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.

Example:

scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions.

Since TraversableOnce has no ++ method, we have to implement that directly, but Traversable and down can use the overload.

As with ++, returns a new collection containing the elements from the left operand followed by the elements from the right operand.

It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one. Mnemonic: the COLon is on the side of the new COLlection type.

Example:

scala> val x = List(1)
x: List[Int] = List(1)

scala> val y = LinkedList(2)
y: scala.collection.mutable.LinkedList[Int] = LinkedList(2)

scala> val z = x ++: y
z: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2)

Creates a new set from this set with some elements removed.

This method takes two or more elements to be removed. Another overloaded variant of this method handles the case where a single element is removed.

Creates a new set from this set by removing all elements of another collection.

Applies a binary operator to a start value and all elements of this set, 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 = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(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: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Applies a binary operator to all elements of this set and a start value, going right to left.

Note: :\ is alternate syntax for foldRight; xs :\ z is the same as xs foldRight z.

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 = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

scala> val b = (a :\ 5)(_+_)
b: Int = 15

scala> val c = (a :\ 5)((x,y) => x + y)
c: Int = 15

Test two objects for equality. The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

Appends all elements of this set to a string builder. The written text consists of the string representations (w.r.t. the method toString) of all elements of this set without any separator string.

Example:

scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> val h = a.addString(b)
b: StringBuilder = 1234

Appends all elements of this set 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 set, separated by the string sep.

Example:

scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> a.addString(b, ", ")
res0: StringBuilder = 1, 2, 3, 4

Appends all elements of this set 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 set are separated by the string sep.

Example:

scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

scala> val b = new StringBuilder()
b: StringBuilder =

scala> a.addString(b, "LinkedList(", ", ", ")")
res1: StringBuilder = LinkedList(1, 2, 3, 4)

Aggregates the results of applying an operator to subsequent elements.

This is a more general form of fold and reduce. It has similar semantics, but does not require the result to be a supertype of the element type. It traverses the elements in different partitions sequentially, using seqop to update the result, and then applies combop to results from different partitions. The implementation of this operation may operate on an arbitrary number of collection partitions, so combop may be invoked an arbitrary number of times.

For example, one might want to process some elements and then produce a Set. In this case, seqop would process an element and append it to the list, while combop would concatenate two lists from different partitions together. The initial value z would be an empty set.

pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)

Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).

Composes two instances of Function1 in a new Function1, with this function applied first.

Tests if some element is contained in this set.

This method is equivalent to contains. It allows sets to be interpreted as predicates.

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.

Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.

Create a copy of the receiver object.

The default implementation of the clone method is platform dependent.

Builds a new collection by applying a partial function to all elements of this set on which the function is defined.

Finds the first element of the set for which the given partial function is defined, and applies the partial function to it.

Note: might return different results for different runs, unless the underlying collection type is ordered.

The factory companion object that builds instances of class Set. (or its Iterable superclass where class Set is not a Seq.)

Composes two instances of Function1 in a new Function1, with this function applied last.

Copies elements of this set to an array. Fills the given array xs with at most len elements of this set, starting at position start. Copying will stop once either the end of the current set is reached, or the end of the array is reached, or len elements have been copied.

Copies values of this set to an array. Fills the given array xs with values of this set. Copying will stop once either the end of the current set is reached, or the end of the array is reached.

Copies values of this set to an array. Fills the given array xs with values of this set, beginning at index start. Copying will stop once either the end of the current set is reached, or the end of the array is reached.

Copies all elements of this set to a buffer.

Counts the number of elements in the set which satisfy a predicate.

Computes the difference of this set and another set.

Selects all elements except first n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Selects all elements except last n ones.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Drops longest prefix of elements that satisfy a predicate.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Tests whether the argument (arg0) 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:

• It is consistent: for any non-null instances 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).

Compares this set with another object for equality.

Note: This operation contains an unchecked cast: if that is a set, it will assume with an unchecked cast that it has the same element type as this set. Any subsequent ClassCastException is treated as a false result.

Tests whether a predicate holds for some of the elements of this set.

Selects all elements of this set which satisfy a predicate.

Selects all elements of this set which do not satisfy a predicate.

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.

Finds the first element of the set satisfying a predicate, if any.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Builds a new collection by applying a function to all elements of this set and using the elements of the resulting collections.

For example:

def getWords(lines: Seq[String]): Seq[String] = lines flatMap (line => line split "\\W+")

The type of the resulting collection is guided by the static type of set. This might cause unexpected results sometimes. For example:

// lettersOf will return a Seq[Char] of likely repeated letters, instead of a Set
def lettersOf(words: Seq[String]) = words flatMap (word => word.toSet)

// lettersOf will return a Set[Char], not a Seq
def lettersOf(words: Seq[String]) = words.toSet flatMap (word => word.toSeq)

// xs will be a an Iterable[Int]
val xs = Map("a" -> List(11,111), "b" -> List(22,222)).flatMap(_._2)

// ys will be a Map[Int, Int]
val ys = Map("a" -> List(1 -> 11,1 -> 111), "b" -> List(2 -> 22,2 -> 222)).flatMap(_._2)

Converts this set of traversable collections into a set formed by the elements of these traversable collections.

The resulting collection's type will be guided by the static type of set. For example:

val xs = List(Set(1, 2, 3), Set(1, 2, 3))
// xs == List(1, 2, 3, 1, 2, 3)

val ys = Set(List(1, 2, 3), List(3, 2, 1))
// ys == Set(1, 2, 3)

Folds the elements of this set using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Applies a binary operator to a start value and all elements of this set, going left to right.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Applies a binary operator to all elements of this set and a start value, going right to left.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Tests whether a predicate holds for all elements of this set.

Applies a function f to all elements of this set.

Note: this method underlies the implementation of most other bulk operations. Subclasses should re-implement this method if a more efficient implementation exists.

Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).

The generic builder that builds instances of Set at arbitrary element types.

A representation that corresponds to the dynamic class of the receiver object.

The nature of the representation is platform dependent.

Partitions this set into a map of sets according to some discriminator function.

Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new set.

Partitions elements in fixed size sets.

Tests whether this set is known to have a finite size. All strict collections are known to have finite size. For a non-strict collection such as Stream, the predicate returns true if all elements have been computed. It returns false if the stream is not yet evaluated to the end.

Note: many collection methods will not work on collections of infinite sizes.

The hashCode method for reference types. See hashCode in scala.Any.

Selects the first element of this set.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Optionally selects the first element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Selects all elements except the last.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Iterates over the inits of this set. The first value will be this set and the final one will be an empty set, with the intervening values the results of successive applications of init.

Computes the intersection between this set and another set.

Tests if this set is empty.

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.

Tests whether this set can be repeatedly traversed.

Selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Optionally selects the last element.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Builds a new collection by applying a function to all elements of this set.

Finds the largest element.

Finds the smallest element.

Displays all elements of this set in a string.

Displays all elements of this set in a string using a separator string.

Displays all elements of this set in a string using start, end, and separator strings.

Equivalent to !(this eq that).

A common implementation of newBuilder for all sets in terms of empty. Overridden for mutable sets in `mutable.SetLike`.

Tests whether the set is not empty.

Wakes up a single thread that is waiting on the receiver object's monitor.

Wakes up all threads that are waiting on the receiver object's monitor.

Returns a parallel implementation of this collection.

For most collection types, this method creates a new parallel collection by copying all the elements. For these collection, par takes linear time. Mutable collections in this category do not produce a mutable parallel collection that has the same underlying dataset, so changes in one collection will not be reflected in the other one.

Specific collections (e.g. ParArray or mutable.ParHashMap) override this default behaviour by creating a parallel collection which shares the same underlying dataset. For these collections, par takes constant or sublinear time.

All parallel collections return a reference to themselves.

The default par implementation uses the combiner provided by this method to create a new parallel collection.

Partitions this set in two sets according to a predicate.

Multiplies up the elements of this collection.

Reduces the elements of this set using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Applies a binary operator to all elements of this set, going left to right.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Optionally applies a binary operator to all elements of this set, going left to right.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Reduces the elements of this set, if any, using the specified associative binary operator.

The order in which operations are performed on elements is unspecified and may be nondeterministic.

Applies a binary operator to all elements of this set, going right to left.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

Optionally applies a binary operator to all elements of this set, going right to left.

Note: might return different results for different runs, unless the underlying collection type is ordered. or the operator is associative and commutative.

The collection of type set underlying this TraversableLike object. By default this is implemented as the TraversableLike object itself, but this can be overridden.

Checks if the other iterable collection contains the same elements in the same order as this set.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Computes a prefix scan of the elements of the collection.

Note: The neutral element z may be applied more than once.

Produces a collection containing cumulative results of applying the operator going left to right.

Note: might return different results for different runs, unless the underlying collection type is ordered.

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: might return different results for different runs, unless the underlying collection type is ordered.

Example:

List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)

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.

The size of this set.

Selects an interval of elements. The returned collection is made up of all elements x which satisfy the invariant:

from <= indexOf(x) < until

Note: might return different results for different runs, unless the underlying collection type is ordered.

Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)

Groups elements in fixed size blocks by passing a "sliding window" over them (as opposed to partitioning them, as is done in grouped.)

Splits this set into a prefix/suffix pair according to a predicate.

Note: c span p is equivalent to (but possibly more efficient than) (c takeWhile p, c dropWhile p), provided the evaluation of the predicate p does not cause any side-effects.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Splits this set into two at a given position. Note: c splitAt n is equivalent to (but possibly more efficient than) (c take n, c drop n).

Note: might return different results for different runs, unless the underlying collection type is ordered.

Defines the prefix of this object's toString representation.

Tests whether this set is a subset of another set.

An iterator over all subsets of this set.

An iterator over all subsets of this set of the given size. If the requested size is impossible, an empty iterator is returned.

Sums up the elements of this collection.

Selects all elements except the first.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Iterates over the tails of this set. The first value will be this set and the final one will be an empty set, with the intervening values the results of successive applications of tail.

Selects first n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Selects last n elements.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Takes longest prefix of elements that satisfy a predicate.

Note: might return different results for different runs, unless the underlying collection type is ordered.

The underlying collection seen as an instance of Set. By default this is implemented as the current collection object itself, but this can be overridden.

Converts this set into another by copying all elements.

Converts this set to an array.

Converts this set to a mutable buffer.

A conversion from collections of type Repr to Set objects. By default this is implemented as just a cast, but this can be overridden.

Converts this set to an indexed sequence.

Converts this set 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).

Returns an Iterator over the elements in this set. Will return the same Iterator if this instance is already an Iterator.

Converts this set to a list.

Converts this set 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.

Converts this set to a sequence. As with toIterable, it's lazy in this default implementation, as this TraversableOnce may be lazy and unevaluated.

Converts this set to a set.

Converts this set to a stream.

Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

Converts this set to an unspecified Traversable. Will return the same collection if this instance is already Traversable.

Converts this set to a Vector.

Transposes this set of traversable collections into a set of sets.

Computes the union between of set and another set.

Converts this set of pairs into two collections of the first and second half of each pair.

Converts this set of triples into three collections of the first, second, and third element of each triple.

Creates a non-strict view of a slice of this set.

Note: the difference between view and slice is that view produces a view of the current set, whereas slice produces a new set.

Note: view(from, to) is equivalent to view.slice(from, to)

Note: might return different results for different runs, unless the underlying collection type is ordered.

Creates a non-strict view of this set.

Creates a non-strict filter of this set.

Note: the difference between c filter p and c withFilter p is that the former creates a new collection, whereas the latter only restricts the domain of subsequent map, flatMap, foreach, and withFilter operations.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Returns a set formed from this set and another iterable collection by combining corresponding elements in pairs. If one of the two collections is longer than the other, its remaining elements are ignored.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Returns a set formed from this set and another iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements are used to extend the shorter collection to the length of the longer.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Zips this set with its indices.

Note: might return different results for different runs, unless the underlying collection type is ordered.

Computes the union between this set and another set.

Note: Same as union.

A syntactic sugar for out of order folding. See fold.

Example:

scala> val a = LinkedList(1,2,3,4)
a: scala.collection.mutable.LinkedList[Int] = LinkedList(1, 2, 3, 4)

scala> val b = (a /:\ 5)(_+_)
b: Int = 15