c

LazyList

Companion object LazyList

final classLazyList[+A] extends AbstractSeq[A] with LinearSeq[A] with LinearSeqOps[A, LazyList, LazyList[A]] with IterableFactoryDefaults[A, LazyList] with Serializable

This class implements an immutable linked list. We call it "lazy" because it computes its elements only when they are needed.

Elements are memoized; that is, the value of each element is computed at most once.

Elements are computed in-order and are never skipped. In other words, accessing the tail causes the head to be computed first.

How lazy is a `LazyList`? When you have a value of type `LazyList`, you don't know yet whether the list is empty or not. If you learn that it is non-empty, then you also know that the head has been computed. But the tail is itself a `LazyList`, whose emptiness-or-not might remain undetermined.

A `LazyList` may be infinite. For example, `LazyList.from(0)` contains all of the natural numbers 0, 1, 2, and so on. For infinite sequences, some methods (such as `count`, `sum`, `max` or `min`) will not terminate.

Here is an example:

```import scala.math.BigInt
object Main extends App {
val fibs: LazyList[BigInt] =
BigInt(0) #:: BigInt(1) #:: fibs.zip(fibs.tail).map{ n => n._1 + n._2 }
fibs.take(5).foreach(println)
}

// prints
//
// 0
// 1
// 1
// 2
// 3```

To illustrate, let's add some output to the definition `fibs`, so we see what's going on.

```import scala.math.BigInt
object Main extends App {
val fibs: LazyList[BigInt] =
BigInt(0) #:: BigInt(1) #::
fibs.zip(fibs.tail).map{ n =>
n._1 + n._2
}
fibs.take(5).foreach(println)
fibs.take(6).foreach(println)
}

// prints
//
// 0
// 1
// 1
// 2
// 3

// And then prints
//
// 0
// 1
// 1
// 2
// 3
// 5```

Note that the definition of `fibs` uses `val` not `def`. The memoization of the `LazyList` requires us to have somewhere to store the information and a `val` allows us to do that.

Further remarks about the semantics of `LazyList`:

• Though the `LazyList` changes as it is accessed, this does not contradict its immutability. Once the values are memoized they do not change. Values that have yet to be memoized still "exist", they simply haven't been computed yet.
• One must be cautious of memoization; it can eat up memory if you're not careful. That's because memoization of the `LazyList` creates a structure much like scala.collection.immutable.List. As long as something is holding on to the head, the head holds on to the tail, and so on recursively. If, on the other hand, there is nothing holding on to the head (e.g. if we used `def` to define the `LazyList`) then once it is no longer being used directly, it disappears.
• Note that some operations, including drop, dropWhile, flatMap or collect may process a large number of intermediate elements before returning.

Here's another example. Let's start with the natural numbers and iterate over them.

```// We'll start with a silly iteration
def loop(s: String, i: Int, iter: Iterator[Int]): Unit = {
// Stop after 200,000
if (i < 200001) {
if (i % 50000 == 0) println(s + i)
loop(s, iter.next(), iter)
}
}

// Our first LazyList definition will be a val definition
val lazylist1: LazyList[Int] = {
def loop(v: Int): LazyList[Int] = v #:: loop(v + 1)
loop(0)
}

// Because lazylist1 is a val, everything that the iterator produces is held
// by virtue of the fact that the head of the LazyList is held in lazylist1
val it1 = lazylist1.iterator
loop("Iterator1: ", it1.next(), it1)

// We can redefine this LazyList such that all we have is the Iterator left
// and allow the LazyList to be garbage collected as required.  Using a def
// to provide the LazyList ensures that no val is holding onto the head as
// is the case with lazylist1
def lazylist2: LazyList[Int] = {
def loop(v: Int): LazyList[Int] = v #:: loop(v + 1)
loop(0)
}
val it2 = lazylist2.iterator
loop("Iterator2: ", it2.next(), it2)

// And, of course, we don't actually need a LazyList at all for such a simple
// problem.  There's no reason to use a LazyList if you don't actually need
// one.
val it3 = new Iterator[Int] {
var i = -1
def hasNext = true
def next(): Int = { i += 1; i }
}
loop("Iterator3: ", it3.next(), it3)```
• In the `fibs` example earlier, the fact that `tail` works at all is of interest. `fibs` has an initial `(0, 1, LazyList(...))`, so `tail` is deterministic. If we defined `fibs` such that only `0` were concretely known, then the act of determining `tail` would require the evaluation of `tail`, so the computation would be unable to progress, as in this code:
```// The first time we try to access the tail we're going to need more
// information which will require us to recurse, which will require us to
// recurse, which...
lazy val sov: LazyList[Vector[Int]] = Vector(0) #:: sov.zip(sov.tail).map { n => n._1 ++ n._2 }```

The definition of `fibs` above creates a larger number of objects than necessary depending on how you might want to implement it. The following implementation provides a more "cost effective" implementation due to the fact that it has a more direct route to the numbers themselves:

```lazy val fib: LazyList[Int] = {
def loop(h: Int, n: Int): LazyList[Int] = h #:: loop(n, h + n)
loop(1, 1)
}```

The head, the tail and whether the list is empty or not can be initially unknown. Once any of those are evaluated, they are all known, though if the tail is built with `#::` or `#:::`, it's content still isn't evaluated. Instead, evaluating the tails content is deferred until the tails empty status, head or tail is evaluated.

Delaying the evaluation of whether a LazyList is empty or not until it's needed allows LazyList to not eagerly evaluate any elements on a call to `filter`.

Only when it's further evaluated (which may be never!) any of the elements gets forced.

for example:

```def tailWithSideEffect: LazyList[Nothing] = {
println("getting empty LazyList")
LazyList.empty
}

val emptyTail = tailWithSideEffect // prints "getting empty LazyList"

val suspended = 1 #:: tailWithSideEffect // doesn't print anything
val tail = suspended.tail // although the tail is evaluated, *still* nothing is yet printed
val filtered = tail.filter(_ => false) // still nothing is printed
filtered.isEmpty // prints "getting empty LazyList"```
A

the type of the elements contained in this lazy list.

Annotations
()
Source
LazyList.scala

"Scala's Collection Library overview" section on `LazyLists` for more information.

Type Hierarchy
Ordering
1. Alphabetic
2. By Inheritance
Inherited
1. LazyList
2. Serializable
3. LinearSeq
4. LinearSeqOps
5. LinearSeq
6. LinearSeqOps
7. AbstractSeq
8. Seq
9. SeqOps
10. Iterable
11. AbstractSeq
12. Seq
13. Equals
14. SeqOps
15. PartialFunction
16. Function1
17. AbstractIterable
18. Iterable
19. IterableFactoryDefaults
20. IterableOps
21. IterableOnceOps
22. IterableOnce
23. AnyRef
24. Any
Implicitly
1. by UnliftOps
2. by iterableOnceExtensionMethods
3. by toDeferrer
5. by StringFormat
6. by Ensuring
7. by ArrowAssoc
1. Hide All
2. Show All
Visibility
1. Public
2. Protected

Value Members

1. final def !=(arg0: Any)

Test two objects for inequality.

Test two objects for inequality.

returns

`true` if !(this == that), false otherwise.

Definition Classes
AnyRef → Any
2. final def ##: Int

Equivalent to `x.hashCode` except for boxed numeric types and `null`.

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`.

returns

a hash value consistent with ==

Definition Classes
AnyRef → Any
3. def #::[B >: A](elem: => B): LazyList[B]

Construct a LazyList consisting of a given first element followed by elements from another LazyList.

Construct a LazyList consisting of a given first element followed by elements from another LazyList.

Implicit
This member is added by an implicit conversion from LazyList[A] toDeferrer[A] performed by method toDeferrer in scala.collection.immutable.LazyList.
Definition Classes
Deferrer
4. def #:::[B >: A](prefix: LazyList[B]): LazyList[B]

Construct a LazyList consisting of the concatenation of the given LazyList and another LazyList.

Construct a LazyList consisting of the concatenation of the given LazyList and another LazyList.

Implicit
This member is added by an implicit conversion from LazyList[A] toDeferrer[A] performed by method toDeferrer in scala.collection.immutable.LazyList.
Definition Classes
Deferrer
5. def +(other: String)
Implicit
This member is added by an implicit conversion from LazyList[A] toany2stringadd[LazyList[A]] performed by method any2stringadd in scala.Predef.
Definition Classes
6. final def ++[B >: A](suffix: IterableOnce[B]): LazyList[B]

Alias for `concat`

Alias for `concat`

Definition Classes
IterableOps
Annotations
()
7. final def ++:[B >: A](prefix: IterableOnce[B]): LazyList[B]

Alias for `prependedAll`.

Alias for `prependedAll`.

Definition Classes
SeqOpsIterableOps
Annotations
()
8. final def +:[B >: A](elem: B): LazyList[B]

Alias for `prepended`.

Alias for `prepended`.

Note that :-ending operators are right associative (see example). A mnemonic for `+:` vs. `:+` is: the COLon goes on the COLlection side.

Definition Classes
SeqOps
Annotations
()
9. def ->[B](y: B): (LazyList[A], B)
Implicit
This member is added by an implicit conversion from LazyList[A] toArrowAssoc[LazyList[A]] performed by method ArrowAssoc in scala.Predef.This conversion will take place only if A is a subclass of Option[Nothing] (A <: Option[Nothing]).
Definition Classes
ArrowAssoc
Annotations
()
10. final def :+[B >: A](elem: B): LazyList[B]

Alias for `appended`.

Alias for `appended`.

Note that :-ending operators are right associative (see example). A mnemonic for `+:` vs. `:+` is: the COLon goes on the COLlection side.

Definition Classes
SeqOps
Annotations
()
11. final def :++[B >: A](suffix: IterableOnce[B]): LazyList[B]

Alias for `appendedAll`.

Alias for `appendedAll`.

Definition Classes
SeqOps
Annotations
()
12. final def ==(arg0: Any)

The expression `x == that` is equivalent to `if (x eq null) that eq null else x.equals(that)`.

The expression `x == that` is equivalent to `if (x eq null) that eq null else x.equals(that)`.

returns

`true` if the receiver object is equivalent to the argument; `false` otherwise.

Definition Classes
AnyRef → Any
13. def addString(, start: String, sep: String, end: String): sb.type

Appends all elements of this lazy list to a string builder using start, end, and separator strings.

Appends all elements of this lazy list 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 lazy list are separated by the string `sep`.

An undefined state is represented with `"<not computed>"` and cycles are represented with `"<cycle>"`.

This method evaluates all elements of the collection.

sb

the string builder to which elements are appended.

start

the starting string.

sep

the separator string.

end

the ending string.

returns

the string builder `b` to which elements were appended.

Definition Classes
LazyListIterableOnceOps

Appends all elements of this lazy list to a string builder.

Appends all elements of this lazy list to a string builder. The written text consists of the string representations (w.r.t. the method `toString`) of all elements of this lazy list 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 =

h: StringBuilder = 1234```
b

the string builder to which elements are appended.

returns

the string builder `b` to which elements were appended.

Definition Classes
IterableOnceOps
Annotations
()
15. final def addString(, sep: String): b.type

Appends all elements of this lazy list to a string builder using a separator string.

Appends all elements of this lazy list 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 lazy list, 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 =

res0: StringBuilder = 1, 2, 3, 4```
b

the string builder to which elements are appended.

sep

the separator string.

returns

the string builder `b` to which elements were appended.

Definition Classes
IterableOnceOps
Annotations
()
16. def andThen[C](k: PartialFunction[A, C]): PartialFunction[Int, C]

Composes this partial function with another partial function that gets applied to results of this partial function.

Composes this partial function with another partial function that gets applied to results of this partial function.

Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.

C

the result type of the transformation function.

k

the transformation function

returns

a partial function with the domain of this partial function narrowed by other partial function, which maps arguments `x` to `k(this(x))`.

Definition Classes
PartialFunction
17. def andThen[C](k: (A) => C): PartialFunction[Int, C]

Composes this partial function with a transformation function that gets applied to results of this partial function.

Composes this partial function with a transformation function that gets applied to results of this partial function.

If the runtime type of the function is a `PartialFunction` then the other `andThen` method is used (note its cautions).

C

the result type of the transformation function.

k

the transformation function

returns

a partial function with the domain of this partial function, possibly narrowed by the specified function, which maps arguments `x` to `k(this(x))`.

Definition Classes
PartialFunctionFunction1
18. def appended[B >: A](elem: B): LazyList[B]

A copy of this lazy list with an element appended.

A copy of this lazy list with an element appended.

Note: will not terminate for infinite-sized collections.

Example:

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

scala> val b = a :+ 2
b: List[Int] = List(1, 2)

scala> println(a)
List(1)```

This method preserves laziness; elements are only evaluated individually as needed.

Note: Repeated chaining of calls to append methods (`appended`, `appendedAll`, `lazyAppendedAll`) without forcing any of the intermediate resulting lazy lists may overflow the stack when the final result is forced.

B

the element type of the returned lazy list.

elem

the appended element

returns

a new lazy list consisting of all elements of this lazy list followed by `value`.

Definition Classes
LazyListSeqOps
19. def appendedAll[B >: A](suffix: IterableOnce[B]): LazyList[B]

Returns a new lazy list containing the elements from the left hand operand followed by the elements from the right hand operand.

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

This method preserves laziness; elements are only evaluated individually as needed.

Note: Repeated chaining of calls to append methods (`appended`, `appendedAll`, `lazyAppendedAll`) without forcing any of the intermediate resulting lazy lists may overflow the stack when the final result is forced.

B

the element type of the returned collection.

suffix

the iterable to append.

returns

a new collection of type `CC[B]` which contains all elements of this lazy list followed by all elements of `suffix`.

Definition Classes
LazyListSeqOps
20. def apply(n: Int): A

Gets the element at the specified index.

Gets the element at the specified index. This operation is provided for convenience in `Seq`. It should not be assumed to be efficient unless you have an `IndexedSeq`.

Definition Classes
LinearSeqOpsSeqOps
Annotations
(cause = scala.this.throws.<init>\$default\$1[IndexOutOfBoundsException])
21. def applyOrElse[A1 <: Int, B1 >: A](x: A1, default: (A1) => B1): B1

Applies this partial function to the given argument when it is contained in the function domain.

Applies this partial function to the given argument when it is contained in the function domain. Applies fallback function where this partial function is not defined.

Note that expression `pf.applyOrElse(x, default)` is equivalent to

`if(pf isDefinedAt x) pf(x) else default(x)`

except that `applyOrElse` method can be implemented more efficiently. For all partial function literals the compiler generates an `applyOrElse` implementation which avoids double evaluation of pattern matchers and guards. This makes `applyOrElse` the basis for the efficient implementation for many operations and scenarios, such as:

• combining partial functions into `orElse`/`andThen` chains does not lead to excessive `apply`/`isDefinedAt` evaluation
• `lift` and `unlift` do not evaluate source functions twice on each invocation
• `runWith` allows efficient imperative-style combining of partial functions with conditionally applied actions

For non-literal partial function classes with nontrivial `isDefinedAt` method it is recommended to override `applyOrElse` with custom implementation that avoids double `isDefinedAt` evaluation. This may result in better performance and more predictable behavior w.r.t. side effects.

x

the function argument

default

the fallback function

returns

the result of this function or fallback function application.

Definition Classes
PartialFunction
22. final def asInstanceOf[T0]: T0

Forces the compiler to treat the receiver object as having type `T0`, even though doing so may violate type safety.

Forces the compiler to treat the receiver object as having type `T0`, even though doing so may violate type safety.

This method is useful when you believe you have type information the compiler doesn't, and it also isn't possible to check the type at runtime. In such situations, skipping type safety is the only option.

It is platform dependent whether `asInstanceOf` has any effect at runtime. It might do a runtime type test on the erasure of `T0`, insert a conversion (such as boxing/unboxing), fill in a default value, or do nothing at all.

In particular, `asInstanceOf` is not a type test. It does **not** mean:

```this match {
case x: T0 => x
case _     => throw ClassCastException("...")```

Use pattern matching or isInstanceOf for type testing instead.

Situations where `asInstanceOf` is useful:

• when flow analysis fails to deduce `T0` automatically
• when down-casting a type parameter or an abstract type member (which cannot be checked at runtime due to type erasure) If there is any doubt and you are able to type test instead, you should do so.

Be careful of using `asInstanceOf` when `T0` is a primitive type. When `T0` is primitive, `asInstanceOf` may insert a conversion instead of a type test. If your intent is to convert, use a `toT` method (`x.toChar`, `x.toByte`, etc.).

returns

Definition Classes
Any
Exceptions thrown

`ClassCastException` if the receiver is not an instance of the erasure of `T0`, if that can be checked on this platform

23. def canEqual(that: Any)

Checks whether this instance can possibly equal `that`.

Checks whether this instance can possibly equal `that`.

A method that should be called from every well-designed equals method that is open to be overridden in a subclass. See Programming in Scala, Chapter 28 for discussion and design.

that

the value being probed for possible equality

returns

true if this instance can possibly equal `that`, otherwise false

Definition Classes
SeqEquals
24. def className

Defines the prefix of this object's `toString` representation.

Defines the prefix of this object's `toString` representation.

It is recommended to return the name of the concrete collection type, but not implementation subclasses. For example, for `ListMap` this method should return `"ListMap"`, not `"Map"` (the supertype) or `"Node"` (an implementation subclass).

The default implementation returns "Iterable". It is overridden for the basic collection kinds "Seq", "IndexedSeq", "LinearSeq", "Buffer", "Set", "Map", "SortedSet", "SortedMap" and "View".

returns

a string representation which starts the result of `toString` applied to this lazy list. By default the string prefix is the simple name of the collection class lazy list.

Attributes
protected[this]
Definition Classes
LazyListIterable
25. def clone()

Create a copy of the receiver object.

Create a copy of the receiver object.

The default implementation of the `clone` method is platform dependent.

returns

a copy of the receiver object.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
(classOf[java.lang.CloneNotSupportedException]) ()
Note

not specified by SLS as a member of AnyRef

26. final def coll: LazyList.this.type

returns

This collection as a `C`.

Attributes
protected
Definition Classes
IterableIterableOps
27. def collect[B](pf: PartialFunction[A, B]): LazyList[B]

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

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

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned lazy list.

pf

the partial function which filters and maps the lazy list.

returns

a new lazy list resulting from applying the given partial function `pf` to each element on which it is defined and collecting the results. The order of the elements is preserved.

Definition Classes
LazyListIterableOpsIterableOnceOps
28. def collectFirst[B](pf: PartialFunction[A, B]): Option[B]

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

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

Note: may not terminate for infinite-sized collections.

This method does not evaluate any elements further than the first element for which the partial function is defined.

pf

the partial function

returns

an option value containing pf applied to the first value for which it is defined, or `None` if none exists.

Definition Classes
LazyListIterableOnceOps
Annotations
()
29. def combinations(n: Int): Iterator[LazyList[A]]

Iterates over combinations of elements.

Iterates over combinations of elements.

A combination of length `n` is a sequence of `n` elements selected in order of their first index in this sequence.

For example, `"xyx"` has two combinations of length 2. The `x` is selected first: `"xx"`, `"xy"`. The sequence `"yx"` is not returned as a combination because it is subsumed by `"xy"`.

If there is more than one way to generate the same combination, only one will be returned.

For example, the result `"xy"` arbitrarily selected one of the `x` elements.

As a further illustration, `"xyxx"` has three different ways to generate `"xy"` because there are three elements `x` to choose from. Moreover, there are three unordered pairs `"xx"` but only one is returned.

It is not specified which of these equal combinations is returned. It is an implementation detail that should not be relied on. For example, the combination `"xx"` does not necessarily contain the first `x` in this sequence. This behavior is observable if the elements compare equal but are not identical.

As a consequence, `"xyx".combinations(3).next()` is `"xxy"`: the combination does not reflect the order of the original sequence, but the order in which elements were selected, by "first index"; the order of each `x` element is also arbitrary.

Note: Even when applied to a view or a lazy collection it will always force the elements.

returns

An Iterator which traverses the n-element combinations of this lazy list.

Definition Classes
SeqOps
Example:
1. ```Seq('a', 'b', 'b', 'b', 'c').combinations(2).foreach(println)
// List(a, b)
// List(a, c)
// List(b, b)
// List(b, c)
Seq('b', 'a', 'b').combinations(2).foreach(println)
// List(b, b)
// List(b, a)```
30. def compose[R](k: PartialFunction[R, Int]): PartialFunction[R, A]

Composes another partial function `k` with this partial function so that this partial function gets applied to results of `k`.

Composes another partial function `k` with this partial function so that this partial function gets applied to results of `k`.

Note that calling isDefinedAt on the resulting partial function may apply the first partial function and execute its side effect. For efficiency, it is recommended to call applyOrElse instead of isDefinedAt or apply.

R

the parameter type of the transformation function.

k

the transformation function

returns

a partial function with the domain of other partial function narrowed by this partial function, which maps arguments `x` to `this(k(x))`.

Definition Classes
PartialFunction
31. def compose[A](g: (A) => Int): (A) => A

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

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

A

the type to which function `g` can be applied

g

a function A => T1

returns

a new function `f` such that `f(x) == apply(g(x))`

Definition Classes
Function1
Annotations
()
32. final def concat[B >: A](suffix: IterableOnce[B]): LazyList[B]

Returns a new lazy list containing the elements from the left hand operand followed by the elements from the right hand operand.

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

B

the element type of the returned collection.

suffix

the iterable to append.

returns

a new lazy list which contains all elements of this lazy list followed by all elements of `suffix`.

Definition Classes
SeqOpsIterableOps
Annotations
()
33. def contains[A1 >: A](elem: A1)

Tests whether this lazy list contains a given value as an element.

Tests whether this lazy list contains a given value as an element.

Note: may not terminate for infinite-sized collections.

elem

the element to test.

returns

`true` if this lazy list has an element that is equal (as determined by `==`) to `elem`, `false` otherwise.

Definition Classes
LinearSeqOpsSeqOps
34. def containsSlice[B >: A](that: collection.Seq[B])

Tests whether this lazy list contains a given sequence as a slice.

Tests whether this lazy list contains a given sequence as a slice.

Note: may not terminate for infinite-sized collections.

that

the sequence to test

returns

`true` if this lazy list contains a slice with the same elements as `that`, otherwise `false`.

Definition Classes
SeqOps
35. def copyToArray[B >: A](xs: Array[B], start: Int, len: Int): Int

Copy elements to an array, returning the number of elements written.

Copy elements to an array, returning the number of elements written.

Fills the given array `xs` starting at index `start` with at most `len` elements of this lazy list.

Copying will stop once either all the elements of this lazy list have been copied, or the end of the array is reached, or `len` elements have been copied.

B

the type of the elements of the array.

xs

the array to fill.

start

the starting index of xs.

len

the maximal number of elements to copy.

returns

the number of elements written to the array

Definition Classes
IterableOnceOps
Note

Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

36. def copyToArray[B >: A](xs: Array[B], start: Int): Int

Copies elements to an array, returning the number of elements written.

Copies elements to an array, returning the number of elements written.

Fills the given array `xs` starting at index `start` with values of this lazy list.

Copying will stop once either all the elements of this lazy list have been copied, or the end of the array is reached.

B

the type of the elements of the array.

xs

the array to fill.

start

the starting index of xs.

returns

the number of elements written to the array

Definition Classes
IterableOnceOps
Annotations
()
Note

Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

37. def copyToArray[B >: A](xs: Array[B]): Int

Copies elements to an array, returning the number of elements written.

Copies elements to an array, returning the number of elements written.

Fills the given array `xs` starting at index `start` with values of this lazy list.

Copying will stop once either all the elements of this lazy list have been copied, or the end of the array is reached.

B

the type of the elements of the array.

xs

the array to fill.

returns

the number of elements written to the array

Definition Classes
IterableOnceOps
Annotations
()
Note

Reuse: After calling this method, one should discard the iterator it was called on. Using it is undefined and subject to change.

38. def corresponds[B](that: collection.Seq[B])(p: (A, B) => Boolean)

Tests whether every element of this lazy list relates to the corresponding element of another sequence by satisfying a test predicate.

Tests whether every element of this lazy list relates to the corresponding element of another sequence by satisfying a test predicate.

B

the type of the elements of `that`

that

the other sequence

p

the test predicate, which relates elements from both sequences

returns

`true` if both sequences have the same length and `p(x, y)` is `true` for all corresponding elements `x` of this lazy list and `y` of `that`, otherwise `false`.

Definition Classes
SeqOps
39. def corresponds[B](that: IterableOnce[B])(p: (A, B) => Boolean)

Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.

Tests whether every element of this collection's iterator relates to the corresponding element of another collection by satisfying a test predicate.

Note: will not terminate for infinite-sized collections.

B

the type of the elements of `that`

that

the other collection

p

the test predicate, which relates elements from both collections

returns

`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`

Definition Classes
IterableOnceOps
40. def count(p: (A) => Boolean): Int

Counts the number of elements in the lazy list which satisfy a predicate.

Counts the number of elements in the lazy list which satisfy a predicate.

Note: will not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the number of elements satisfying the predicate `p`.

Definition Classes
IterableOnceOps
41. def diff[B >: A](that: collection.Seq[B]): LazyList[A]

Computes the multiset difference between this lazy list and another sequence.

Computes the multiset difference between this lazy list and another sequence.

This method preserves laziness; elements are only evaluated individually as needed.

that

the sequence of elements to remove

returns

a new lazy list which contains all elements of this lazy list except some of occurrences of elements that also appear in `that`. If an element value `x` appears n times in `that`, then the first n occurrences of `x` will not form part of the result, but any following occurrences will.

Definition Classes
LazyListSeqOps
42. def distinct: LazyList[A]

Selects all the elements of this lazy list ignoring the duplicates.

Selects all the elements of this lazy list ignoring the duplicates.

returns

a new lazy list consisting of all the elements of this lazy list without duplicates.

Definition Classes
SeqOps
43. def distinctBy[B](f: (A) => B): LazyList[A]

Selects all the elements of this lazy list ignoring the duplicates as determined by `==` after applying the transforming function `f`.

Selects all the elements of this lazy list ignoring the duplicates as determined by `==` after applying the transforming function `f`.

B

the type of the elements after being transformed by `f`

f

The transforming function whose result is used to determine the uniqueness of each element

returns

a new lazy list consisting of all the elements of this lazy list without duplicates.

Definition Classes
SeqOps
44. def drop(n: Int): LazyList[A]

Selects all elements except the first `n` ones.

Selects all elements except the first `n` ones.

This method does not evaluate anything until an operation is performed on the result (e.g. calling `head` or `tail`, or checking if it is empty). Additionally, it preserves laziness for all except the first `n` elements.

n

the number of elements to drop from this lazy list.

returns

a lazy list consisting of all elements of this lazy list except the first `n` ones, or else the empty lazy list, if this lazy list has less than `n` elements. If `n` is negative, don't drop any elements.

Definition Classes
LazyListIterableOpsIterableOnceOps
45. def dropRight(n: Int): LazyList[A]

Selects all elements except last n ones.

Selects all elements except last n ones.

This method does not evaluate anything until an operation is performed on the result (e.g. calling `head` or `tail`, or checking if it is empty).

n

the number of elements to drop from this lazy list.

returns

a lazy list consisting of all elements of this lazy list except the last `n` ones, or else the empty lazy list, if this lazy list has less than `n` elements. If `n` is negative, don't drop any elements.

Definition Classes
LazyListIterableOps
46. def dropWhile(p: (A) => Boolean): LazyList[A]

Selects all elements except the longest prefix that satisfies a predicate.

Selects all elements except the longest prefix that satisfies a predicate.

The matching prefix starts with the first element of this lazy list, and the element following the prefix is the first element that does not satisfy the predicate. The matching prefix may be empty, so that this method returns the entire lazy list.

Example:

```scala> List(1, 2, 3, 100, 4).dropWhile(n => n < 10)
val res0: List[Int] = List(100, 4)

scala> List(1, 2, 3, 100, 4).dropWhile(n => n == 0)
val res1: List[Int] = List(1, 2, 3, 100, 4)```

Use span to obtain both the prefix and suffix. Use filterNot to drop all elements that satisfy the predicate.

This method does not evaluate anything until an operation is performed on the result (e.g. calling `head` or `tail`, or checking if it is empty). Additionally, it preserves laziness for all elements after the predicate returns `false`.

p

The predicate used to test elements.

returns

the longest suffix of this lazy list whose first element does not satisfy the predicate `p`.

Definition Classes
LazyListIterableOpsIterableOnceOps
47. def elementWise

Returns an extractor object with a `unapplySeq` method, which extracts each element of a sequence data.

Returns an extractor object with a `unapplySeq` method, which extracts each element of a sequence data.

Definition Classes
PartialFunction
Example:
1. ```val firstChar: String => Option[Char] = _.headOption

Seq("foo", "bar", "baz") match {
case firstChar.unlift.elementWise(c0, c1, c2) =>
println(s"\$c0, \$c1, \$c2") // Output: f, b, b
}```
48. def empty: LazyList[A]

The empty iterable of the same type as this iterable.

The empty iterable of the same type as this iterable.

returns

an empty iterable of type `C`.

Definition Classes
IterableFactoryDefaultsIterableOps
49. def endsWith[B >: A](that: collection.Iterable[B])

Tests whether this lazy list ends with the given sequence.

Tests whether this lazy list ends with the given sequence.

Note: will not terminate for infinite-sized collections.

that

the sequence to test

returns

`true` if this lazy list has `that` as a suffix, `false` otherwise.

Definition Classes
SeqOps
50. def ensuring(cond: (LazyList[A]) => Boolean, msg: => Any): LazyList[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toEnsuring[LazyList[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
51. def ensuring(cond: (LazyList[A]) => Boolean): LazyList[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toEnsuring[LazyList[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
52. def ensuring(cond: Boolean, msg: => Any): LazyList[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toEnsuring[LazyList[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
53. def ensuring(cond: Boolean): LazyList[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toEnsuring[LazyList[A]] performed by method Ensuring in scala.Predef.
Definition Classes
Ensuring
54. final def eq(arg0: AnyRef)

Tests whether the argument (`that`) is a reference to the receiver object (`this`).

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:

• 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`).

returns

`true` if the argument is a reference to the receiver object; `false` otherwise.

Definition Classes
AnyRef
55. def equals(o: Any)

Checks whether this instance is equal to `that`.

Checks whether this instance is equal to `that`. This universal equality method is defined in `AnyRef`.

Definition Classes
SeqEquals → AnyRef → Any
56. def exists(p: (A) => Boolean)

Tests whether a predicate holds for at least one element of this lazy list.

Tests whether a predicate holds for at least one element of this lazy list.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

`true` if the given predicate `p` is satisfied by at least one element of this lazy list, otherwise `false`

Definition Classes
LinearSeqOpsIterableOnceOps
57. def filter(pred: (A) => Boolean): LazyList[A]

Selects all elements of this lazy list which satisfy a predicate.

Selects all elements of this lazy list which satisfy a predicate.

This method preserves laziness; elements are only evaluated individually as needed.

returns

a new lazy list consisting of all elements of this lazy list that satisfy the given predicate `p`. The order of the elements is preserved.

Definition Classes
LazyListIterableOpsIterableOnceOps
58. def filterNot(pred: (A) => Boolean): LazyList[A]

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

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

This method preserves laziness; elements are only evaluated individually as needed.

pred

the predicate used to test elements.

returns

a new lazy list consisting of all elements of this lazy list that do not satisfy the given predicate `pred`. Their order may not be preserved.

Definition Classes
LazyListIterableOpsIterableOnceOps
59. def finalize(): Unit

Called by the garbage collector on the receiver object when there are no more references to the object.

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.

Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
(classOf[java.lang.Throwable])
Note

not specified by SLS as a member of AnyRef

60. def find(p: (A) => Boolean): Option[A]

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

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

Note: may not terminate for infinite-sized collections.

This method does not evaluate any elements further than the first element matching the predicate.

p

the predicate used to test elements.

returns

an option value containing the first element in the lazy list that satisfies `p`, or `None` if none exists.

Definition Classes
LazyListLinearSeqOpsIterableOnceOps
Annotations
()
61. def findLast(p: (A) => Boolean): Option[A]

Finds the last element of the lazy list satisfying a predicate, if any.

Finds the last element of the lazy list satisfying a predicate, if any.

Note: will not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

an option value containing the last element in the lazy list that satisfies `p`, or `None` if none exists.

Definition Classes
LinearSeqOpsSeqOps
62. def flatMap[B](f: (A) => IterableOnce[B]): LazyList[B]

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

Builds a new lazy list by applying a function to all elements of this lazy list 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 lazy list. 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: String) => word.toSeq)

// xs will be 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)```

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned collection.

f

the function to apply to each element.

returns

a new lazy list resulting from applying the given collection-valued function `f` to each element of this lazy list and concatenating the results.

Definition Classes
LazyListIterableOpsIterableOnceOps
63. def flatten[B](implicit asIterable: (A) => IterableOnce[B]): LazyList[B]

Converts this lazy list of iterable collections into a lazy list formed by the elements of these iterable collections.

Converts this lazy list of iterable collections into a lazy list formed by the elements of these iterable collections.

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

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

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

This method preserves laziness; elements are only evaluated individually as needed.

B

the type of the elements of each iterable collection.

asIterable

an implicit conversion which asserts that the element type of this lazy list is an `Iterable`.

returns

a new lazy list resulting from concatenating all element lazy lists.

Definition Classes
LazyListIterableOpsIterableOnceOps
64. def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1

Applies the given binary operator `op` to the given initial value `z` and all elements of this lazy list.

Applies the given binary operator `op` to the given initial value `z` and all elements of this lazy list.

For each application of the operator, each operand is either an element of this lazy list, the initial value, or another such application of the operator.

The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation. The initial value may be used an arbitrary number of times, but at least once.

If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.

Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative. In either case, it is also necessary that the initial value be a neutral value for the operator, e.g. `Nil` for `List` concatenation or `1` for multiplication.

The default implementation in `IterableOnce` is equivalent to `foldLeft` but may be overridden for more efficient traversal orders.

Note: will not terminate for infinite-sized collections.

A1

The type parameter for the binary operator, a supertype of `A`.

z

An initial value; may be used an arbitrary number of times in the computation of the result; must be a neutral value for `op` for the result to always be the same across runs.

op

A binary operator; must be associative for the result to always be the same across runs.

returns

The result of applying `op` between all the elements and `z`, or `z` if this lazy list is empty.

Definition Classes
IterableOnceOps
65. def foldLeft[B](z: B)(op: (B, A) => B): B

LazyList specialization of foldLeft which allows GC to collect along the way.

LazyList specialization of foldLeft which allows GC to collect along the way.

B

The type of value being accumulated.

z

The initial value seeded into the function `op`.

op

The operation to perform on successive elements of the `LazyList`.

returns

The accumulated value from successive applications of `op`.

Definition Classes
LazyListLinearSeqOpsIterableOnceOps
Annotations
()
66. def foldRight[B](z: B)(op: (A, B) => B): B

Applies the given binary operator `op` to all elements of this lazy list and the given initial value `z`, going right to left.

Applies the given binary operator `op` to all elements of this lazy list and the given initial value `z`, going right to left. Returns the initial value if this lazy list is empty.

"Going right to left" only makes sense if this collection is ordered: then if `x1`, `x2`, ..., `xn` are the elements of this lazy list, the result is `op(x1, op(x2, op( ... op(xn, z) ... )))`.

If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the initial value, and each other right operand is itself an application of the operator. The elements of this lazy list and the initial value all appear exactly once in the computation.

Note: will not terminate for infinite-sized collections.

B

The result type of the binary operator.

z

An initial value.

op

A binary operator.

returns

The result of applying `op` to all elements of this lazy list and `z`, going right to left. Returns `z` if this lazy list is empty.

Definition Classes
IterableOnceOps
67. def forall(p: (A) => Boolean)

Tests whether a predicate holds for all elements of this lazy list.

Tests whether a predicate holds for all elements of this lazy list.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

`true` if this lazy list is empty or the given predicate `p` holds for all elements of this lazy list, otherwise `false`.

Definition Classes
LinearSeqOpsIterableOnceOps
68. def force: LazyList.this.type

Evaluates all undefined elements of the lazy list.

Evaluates all undefined elements of the lazy list.

This method detects cycles in lazy lists, and terminates after all elements of the cycle are evaluated. For example:

```val ring: LazyList[Int] = 1 #:: 2 #:: 3 #:: ring
ring.force
ring.toString

// prints
//
// LazyList(1, 2, 3, ...)```

This method will *not* terminate for non-cyclic infinite-sized collections.

returns

this

69. def foreach[U](f: (A) => U): Unit

Apply the given function `f` to each element of this linear sequence (while respecting the order of the elements).

Apply the given function `f` to each element of this linear sequence (while respecting the order of the elements).

f

The treatment to apply to each element.

Definition Classes
LazyListLinearSeqOpsIterableOnceOps
Annotations
()
Note

Overridden here as final to trigger tail-call optimization, which replaces 'this' with 'tail' at each iteration. This is absolutely necessary for allowing the GC to collect the underlying LazyList as elements are consumed.

,

This function will force the realization of the entire LazyList unless the `f` throws an exception.

70. def fromSpecific(coll: IterableOnce[A]): LazyList[A]

Defines how to turn a given `Iterable[A]` into a collection of type `C`.

Defines how to turn a given `Iterable[A]` into a collection of type `C`.

This process can be done in a strict way or a non-strict way (ie. without evaluating the elements of the resulting collections). In other words, this methods defines the evaluation model of the collection.

Attributes
protected
Definition Classes
IterableFactoryDefaultsIterableOps
Note

When implementing a custom collection type and refining `C` to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case where `C =:= CC[A]`, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.

,

As witnessed by the `@uncheckedVariance` annotation, using this method might be unsound. However, as long as it is called with an `Iterable[A]` obtained from `this` collection (as it is the case in the implementations of operations where we use a `View[A]`), it is safe.

71. final def getClass(): Class[_ <: AnyRef]

Returns the runtime class representation of the object.

Returns the runtime class representation of the object.

returns

a class object corresponding to the runtime type of the receiver.

Definition Classes
AnyRef → Any
Annotations
()
72. def groupBy[K](f: (A) => K): Map[K, LazyList[A]]

Partitions this lazy list into a map of lazy lists according to some discriminator function.

Partitions this lazy list into a map of lazy lists according to some discriminator function.

Note: Even when applied to a view or a lazy collection it will always force the elements.

K

the type of keys returned by the discriminator function.

f

the discriminator function.

returns

A map from keys to lazy lists such that the following invariant holds:

`(xs groupBy f)(k) = xs filter (x => f(x) == k)`

That is, every key `k` is bound to a lazy list of those elements `x` for which `f(x)` equals `k`.

Definition Classes
IterableOps
73. def groupMap[K, B](key: (A) => K)(f: (A) => B): Map[K, LazyList[B]]

Partitions this lazy list into a map of lazy lists according to a discriminator function `key`.

Partitions this lazy list into a map of lazy lists according to a discriminator function `key`. Each element in a group is transformed into a value of type `B` using the `value` function.

It is equivalent to `groupBy(key).mapValues(_.map(f))`, but more efficient.

```case class User(name: String, age: Int)

def namesByAge(users: Seq[User]): Map[Int, Seq[String]] =
users.groupMap(_.age)(_.name)```

Note: Even when applied to a view or a lazy collection it will always force the elements.

K

the type of keys returned by the discriminator function

B

the type of values returned by the transformation function

key

the discriminator function

f

the element transformation function

Definition Classes
IterableOps
74. def groupMapReduce[K, B](key: (A) => K)(f: (A) => B)(reduce: (B, B) => B): Map[K, B]

Partitions this lazy list into a map according to a discriminator function `key`.

Partitions this lazy list into a map according to a discriminator function `key`. All the values that have the same discriminator are then transformed by the `f` function and then reduced into a single value with the `reduce` function.

It is equivalent to `groupBy(key).mapValues(_.map(f).reduce(reduce))`, but more efficient.

```def occurrences[A](as: Seq[A]): Map[A, Int] =
as.groupMapReduce(identity)(_ => 1)(_ + _)```

Note: Even when applied to a view or a lazy collection it will always force the elements.

Definition Classes
IterableOps
75. def grouped(size: Int): Iterator[LazyList[A]]

Partitions elements in fixed size lazy lists.

Partitions elements in fixed size lazy lists.

The iterator returned by this method mostly preserves laziness; a single element ahead of the iterator is evaluated.

size

the number of elements per group

returns

An iterator producing lazy lists of size `size`, except the last will be less than size `size` if the elements don't divide evenly.

Definition Classes
LazyListIterableOps
76. def hashCode(): Int

The hashCode method for reference types.

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

returns

the hash code value for this object.

Definition Classes
Seq → AnyRef → Any

<invalid inheritdoc annotation>

<invalid inheritdoc annotation>

Note: *Must* be overridden in subclasses. The default implementation is inherited from IterableOps.

Definition Classes
LazyListLinearSeqOpsIterableOps

Optionally selects the first element.

Optionally selects the first element.

returns

the first element of this lazy list if it is nonempty, `None` if it is empty.

Definition Classes
LinearSeqOpsIterableOps
79. def indexOf[B >: A](elem: B): Int

Finds index of first occurrence of some value in this lazy list.

Finds index of first occurrence of some value in this lazy list.

B

the type of the element `elem`.

elem

the element value to search for.

returns

the index `>= 0` of the first element of this lazy list that is equal (as determined by `==`) to `elem`, or `-1`, if none exists.

Definition Classes
SeqOps
Annotations
()
80. def indexOf[B >: A](elem: B, from: Int): Int

Finds index of first occurrence of some value in this lazy list after or at some start index.

Finds index of first occurrence of some value in this lazy list after or at some start index.

B

the type of the element `elem`.

elem

the element value to search for.

from

the start index

returns

the index `>= from` of the first element of this lazy list that is equal (as determined by `==`) to `elem`, or `-1`, if none exists.

Definition Classes
SeqOps
81. def indexOfSlice[B >: A](that: collection.Seq[B]): Int

Finds first index where this lazy list contains a given sequence as a slice.

Finds first index where this lazy list contains a given sequence as a slice.

Note: may not terminate for infinite-sized collections.

that

the sequence to test

returns

the first index `>= 0` such that the elements of this lazy list starting at this index match the elements of sequence `that`, or `-1` if no such subsequence exists.

Definition Classes
SeqOps
Annotations
()
82. def indexOfSlice[B >: A](that: collection.Seq[B], from: Int): Int

Finds first index after or at a start index where this lazy list contains a given sequence as a slice.

Finds first index after or at a start index where this lazy list contains a given sequence as a slice.

Note: may not terminate for infinite-sized collections.

that

the sequence to test

from

the start index

returns

the first index `>= from` such that the elements of this lazy list starting at this index match the elements of sequence `that`, or `-1` if no such subsequence exists.

Definition Classes
SeqOps
83. def indexWhere(p: (A) => Boolean, from: Int): Int

Finds index of the first element satisfying some predicate after or at some start index.

Finds index of the first element satisfying some predicate after or at some start index.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

from

the start index

returns

the index `>= from` of the first element of this lazy list that satisfies the predicate `p`, or `-1`, if none exists.

Definition Classes
LinearSeqOpsSeqOps
84. def indexWhere(p: (A) => Boolean): Int

Finds index of the first element satisfying some predicate.

Finds index of the first element satisfying some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the index `>= 0` of the first element of this lazy list that satisfies the predicate `p`, or `-1`, if none exists.

Definition Classes
SeqOps
Annotations
()
85. def indices

Produces the range of all indices of this sequence.

Produces the range of all indices of this sequence.

Note: Even when applied to a view or a lazy collection it will always force the elements.

returns

a `Range` value from `0` to one less than the length of this lazy list.

Definition Classes
SeqOps
86. def init: LazyList[A]

The initial part of the collection without its last element.

The initial part of the collection without its last element.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Definition Classes
IterableOps
87. def inits: Iterator[LazyList[A]]

Iterates over the inits of this lazy list.

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

Note: Even when applied to a view or a lazy collection it will always force the elements.

returns

an iterator over all the inits of this lazy list

Definition Classes
IterableOps
Example:
1. `List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)`

88. def intersect[B >: A](that: collection.Seq[B]): LazyList[A]

Computes the multiset intersection between this lazy list and another sequence.

Computes the multiset intersection between this lazy list and another sequence.

This method preserves laziness; elements are only evaluated individually as needed.

that

the sequence of elements to intersect with.

returns

a new lazy list which contains all elements of this lazy list which also appear in `that`. If an element value `x` appears n times in `that`, then the first n occurrences of `x` will be retained in the result, but any following occurrences will be omitted.

Definition Classes
LazyListSeqOps
89. def isDefinedAt(x: Int)

Tests whether this lazy list contains given index.

Tests whether this lazy list contains given index.

The implementations of methods `apply` and `isDefinedAt` turn a `Seq[A]` into a `PartialFunction[Int, A]`.

returns

`true` if this lazy list contains an element at position `idx`, `false` otherwise.

Definition Classes
LinearSeqOpsSeqOps
90. def isEmpty

<invalid inheritdoc annotation>

<invalid inheritdoc annotation>

Note: *Must* be overridden in subclasses. The default implementation that is inherited from SeqOps uses `lengthCompare`, which is defined here to use `isEmpty`.

Definition Classes
LazyListLinearSeqOpsSeqOpsIterableOnceOps
91. final def isInstanceOf[T0]

Test whether the dynamic type of the receiver object has the same erasure as `T0`.

Test whether the dynamic type of the receiver object has the same erasure as `T0`.

Depending on what `T0` is, the test is done in one of the below ways:

• `T0` is a non-parameterized class type, e.g. `BigDecimal`: this method returns `true` if the value of the receiver object is a `BigDecimal` or a subtype of `BigDecimal`.
• `T0` is a parameterized class type, e.g. `List[Int]`: this method returns `true` if the value of the receiver object is some `List[X]` for any `X`. For example, `List(1, 2, 3).isInstanceOf[List[String]]` will return true.
• `T0` is some singleton type `x.type` or literal `x`: this method returns `this.eq(x)`. For example, `x.isInstanceOf[1]` is equivalent to `x.eq(1)`
• `T0` is an intersection `X with Y` or `X & Y: this method is equivalent to `x.isInstanceOf[X] && x.isInstanceOf[Y]
• `T0` is a union `X | Y`: this method is equivalent to `x.isInstanceOf[X] || x.isInstanceOf[Y]`
• `T0` is a type parameter or an abstract type member: this method is equivalent to `isInstanceOf[U]` where `U` is `T0`'s upper bound, `Any` if `T0` is unbounded. For example, `x.isInstanceOf[A]` where `A` is an unbounded type parameter will return true for any value of `x`.

This is exactly equivalent to the type pattern `_: T0`

returns

`true` if the receiver object is an instance of erasure of type `T0`; `false` otherwise.

Definition Classes
Any
Note

due to the unexpectedness of `List(1, 2, 3).isInstanceOf[List[String]]` returning true and `x.isInstanceOf[A]` where `A` is a type parameter or abstract member returning true, these forms issue a warning.

92. def isTraversableAgain

Tests whether this lazy list can be repeatedly traversed.

Tests whether this lazy list can be repeatedly traversed. Always true for Iterables and false for Iterators unless overridden.

returns

`true` if it is repeatedly traversable, `false` otherwise.

Definition Classes
IterableOpsIterableOnceOps
93. def iterableFactory

The companion object of this lazy list, providing various factory methods.

The companion object of this lazy list, providing various factory methods.

Definition Classes
LazyListLinearSeqLinearSeqSeqIterableSeqIterableIterableOps
Note

When implementing a custom collection type and refining `CC` to the new type, this method needs to be overridden to return a factory for the new type (the compiler will issue an error otherwise).

94. def iterator: Iterator[A]

An scala.collection.Iterator over the elements of this lazy list.

An scala.collection.Iterator over the elements of this lazy list.

If an `IterableOnce` object is in fact an scala.collection.Iterator, this method always returns itself, in its current state, but if it is an scala.collection.Iterable, this method always returns a new scala.collection.Iterator.

The iterator returned by this method preserves laziness; elements are only evaluated individually as needed.

Definition Classes
LazyListLinearSeqOpsIterableOnce
95. def knownSize: Int

The number of elements in this lazy list, if it can be cheaply computed, -1 otherwise.

The number of elements in this lazy list, if it can be cheaply computed, -1 otherwise. Cheaply usually means: Not requiring a collection traversal.

This method preserves laziness; elements are only evaluated individually as needed.

Definition Classes
LazyListIterableOnce
96. def last: A

Selects the last element.

Selects the last element.

returns

The last element of this lazy list.

Definition Classes
LinearSeqOpsIterableOps
Exceptions thrown

`NoSuchElementException` If the lazy list is empty.

97. def lastIndexOf[B >: A](elem: B, end: Int = length - 1): Int

Finds index of last occurrence of some value in this lazy list before or at a given end index.

Finds index of last occurrence of some value in this lazy list before or at a given end index.

Note: will not terminate for infinite-sized collections.

B

the type of the element `elem`.

elem

the element value to search for.

end

the end index.

returns

the index `<= end` of the last element of this lazy list that is equal (as determined by `==`) to `elem`, or `-1`, if none exists.

Definition Classes
SeqOps
98. def lastIndexOfSlice[B >: A](that: collection.Seq[B]): Int

Finds last index where this lazy list contains a given sequence as a slice.

Finds last index where this lazy list contains a given sequence as a slice.

Note: will not terminate for infinite-sized collections.

that

the sequence to test

returns

the last index such that the elements of this lazy list starting at this index match the elements of sequence `that`, or `-1` if no such subsequence exists.

Definition Classes
SeqOps
Annotations
()
99. def lastIndexOfSlice[B >: A](that: collection.Seq[B], end: Int): Int

Finds last index before or at a given end index where this lazy list contains a given sequence as a slice.

Finds last index before or at a given end index where this lazy list contains a given sequence as a slice.

Note: will not terminate for infinite-sized collections.

that

the sequence to test

end

the end index

returns

the last index `<= end` such that the elements of this lazy list starting at this index match the elements of sequence `that`, or `-1` if no such subsequence exists.

Definition Classes
SeqOps
100. def lastIndexWhere(p: (A) => Boolean, end: Int): Int

Finds index of last element satisfying some predicate before or at given end index.

Finds index of last element satisfying some predicate before or at given end index.

Note: will not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the index `<= end` of the last element of this lazy list that satisfies the predicate `p`, or `-1`, if none exists.

Definition Classes
LinearSeqOpsSeqOps
101. def lastIndexWhere(p: (A) => Boolean): Int

Finds index of last element satisfying some predicate.

Finds index of last element satisfying some predicate.

Note: will not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the index of the last element of this lazy list that satisfies the predicate `p`, or `-1`, if none exists.

Definition Classes
SeqOps
Annotations
()
102. def lastOption: Option[A]

Optionally selects the last element.

Optionally selects the last element.

returns

the last element of this lazy list\$ if it is nonempty, `None` if it is empty.

Definition Classes
IterableOps
103. def lazyAppendedAll[B >: A](suffix: => IterableOnce[B]): LazyList[B]

The lazy list resulting from the concatenation of this lazy list with the argument lazy list.

The lazy list resulting from the concatenation of this lazy list with the argument lazy list.

This method preserves laziness; elements are only evaluated individually as needed.

Note: Repeated chaining of calls to append methods (`appended`, `appendedAll`, `lazyAppendedAll`) without forcing any of the intermediate resulting lazy lists may overflow the stack when the final result is forced.

suffix

The collection that gets appended to this lazy list

returns

The lazy list containing elements of this lazy list and the iterable object.

104. def lazyZip[B](that: collection.Iterable[B]): LazyZip2[A, B, LazyList.this.type]

Analogous to `zip` except that the elements in each collection are not consumed until a strict operation is invoked on the returned `LazyZip2` decorator.

Analogous to `zip` except that the elements in each collection are not consumed until a strict operation is invoked on the returned `LazyZip2` decorator.

Calls to `lazyZip` can be chained to support higher arities (up to 4) without incurring the expense of constructing and deconstructing intermediary tuples.

```val xs = List(1, 2, 3)
val res = (xs lazyZip xs lazyZip xs lazyZip xs).map((a, b, c, d) => a + b + c + d)
// res == List(4, 8, 12)```

This method is not particularly useful for a lazy list, as zip already preserves laziness.

The `collection.LazyZip2` returned by this method preserves laziness; elements are only evaluated individually as needed.

B

the type of the second element in each eventual pair

that

the iterable providing the second element of each eventual pair

returns

a decorator `LazyZip2` that allows strict operations to be performed on the lazily evaluated pairs or chained calls to `lazyZip`. Implicit conversion to `Iterable[(A, B)]` is also supported.

Definition Classes
LazyListIterable
105. def length: Int

The length (number of elements) of the lazy list.

The length (number of elements) of the lazy list. `size` is an alias for `length` in `Seq` collections.

Definition Classes
LinearSeqOpsSeqOps
106. def lengthCompare(that: collection.Iterable[_]): Int

Compares the length of this lazy list to the size of another `Iterable`.

Compares the length of this lazy list to the size of another `Iterable`.

that

the `Iterable` whose size is compared with this lazy list's length.

returns

A value `x` where

```x <  0       if this.length <  that.size
x == 0       if this.length == that.size
x >  0       if this.length >  that.size```

The method as implemented here does not call `length` or `size` directly; its running time is `O(this.length min that.size)` instead of `O(this.length + that.size)`. The method should be overridden if computing `size` is cheap and `knownSize` returns `-1`.

Definition Classes
LinearSeqOpsSeqOps
107. def lengthCompare(len: Int): Int

Compares the length of this lazy list to a test value.

Compares the length of this lazy list to a test value.

len

the test value that gets compared with the length.

returns

A value `x` where

```x <  0       if this.length <  len
x == 0       if this.length == len
x >  0       if this.length >  len```

The method as implemented here does not call `length` directly; its running time is `O(length min len)` instead of `O(length)`. The method should be overridden if computing `length` is cheap and `knownSize` returns `-1`.

Definition Classes
LinearSeqOpsSeqOps

lengthIs

108. final def lengthIs

Returns a value class containing operations for comparing the length of this lazy list to a test value.

Returns a value class containing operations for comparing the length of this lazy list to a test value.

These operations are implemented in terms of `lengthCompare(Int)`, and allow the following more readable usages:

```this.lengthIs < len     // this.lengthCompare(len) < 0
this.lengthIs <= len    // this.lengthCompare(len) <= 0
this.lengthIs == len    // this.lengthCompare(len) == 0
this.lengthIs != len    // this.lengthCompare(len) != 0
this.lengthIs >= len    // this.lengthCompare(len) >= 0
this.lengthIs > len     // this.lengthCompare(len) > 0```
Definition Classes
SeqOps
Annotations
()
109. def lift: (Int) => Option[A]

Turns this partial function into a plain function returning an `Option` result.

Turns this partial function into a plain function returning an `Option` result.

returns

a function that takes an argument `x` to `Some(this(x))` if `this` is defined for `x`, and to `None` otherwise.

Definition Classes
PartialFunction

Function.unlift

110. def map[B](f: (A) => B): LazyList[B]

Builds a new lazy list by applying a function to all elements of this lazy list.

Builds a new lazy list by applying a function to all elements of this lazy list.

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned lazy list.

f

the function to apply to each element.

returns

a new lazy list resulting from applying the given function `f` to each element of this lazy list and collecting the results.

Definition Classes
LazyListIterableOpsIterableOnceOps
111. def max[B >: A](implicit ord: math.Ordering[B]): A

Finds the largest element.

Finds the largest element.

Note: will not terminate for infinite-sized collections.

B

The type over which the ordering is defined.

ord

An ordering to be used for comparing elements.

returns

the largest element of this lazy list with respect to the ordering `ord`.

Definition Classes
IterableOnceOps
Exceptions thrown

`UnsupportedOperationException` if this lazy list is empty.

112. def maxBy[B](f: (A) => B)(implicit ord: math.Ordering[B]): A

Finds the first element which yields the largest value measured by function `f`.

Finds the first element which yields the largest value measured by function `f`.

Note: will not terminate for infinite-sized collections.

B

The result type of the function `f`.

f

The measuring function.

returns

the first element of this lazy list with the largest value measured by function `f` with respect to the ordering `cmp`.

Definition Classes
IterableOnceOps
Exceptions thrown

`UnsupportedOperationException` if this lazy list is empty.

113. def maxByOption[B](f: (A) => B)(implicit ord: math.Ordering[B]): Option[A]

Finds the first element which yields the largest value measured by function `f`.

Finds the first element which yields the largest value measured by function `f`.

Note: will not terminate for infinite-sized collections.

B

The result type of the function `f`.

f

The measuring function.

returns

an option value containing the first element of this lazy list with the largest value measured by function `f` with respect to the ordering `cmp`.

Definition Classes
IterableOnceOps
114. def maxOption[B >: A](implicit ord: math.Ordering[B]): Option[A]

Finds the largest element.

Finds the largest element.

Note: will not terminate for infinite-sized collections.

B

The type over which the ordering is defined.

ord

An ordering to be used for comparing elements.

returns

an option value containing the largest element of this lazy list with respect to the ordering `ord`.

Definition Classes
IterableOnceOps
115. def min[B >: A](implicit ord: math.Ordering[B]): A

Finds the smallest element.

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

B

The type over which the ordering is defined.

ord

An ordering to be used for comparing elements.

returns

the smallest element of this lazy list with respect to the ordering `ord`.

Definition Classes
IterableOnceOps
Exceptions thrown

`UnsupportedOperationException` if this lazy list is empty.

116. def minBy[B](f: (A) => B)(implicit ord: math.Ordering[B]): A

Finds the first element which yields the smallest value measured by function `f`.

Finds the first element which yields the smallest value measured by function `f`.

Note: will not terminate for infinite-sized collections.

B

The result type of the function `f`.

f

The measuring function.

returns

the first element of this lazy list with the smallest value measured by function `f` with respect to the ordering `cmp`.

Definition Classes
IterableOnceOps
Exceptions thrown

`UnsupportedOperationException` if this lazy list is empty.

117. def minByOption[B](f: (A) => B)(implicit ord: math.Ordering[B]): Option[A]

Finds the first element which yields the smallest value measured by function `f`.

Finds the first element which yields the smallest value measured by function `f`.

Note: will not terminate for infinite-sized collections.

B

The result type of the function `f`.

f

The measuring function.

returns

an option value containing the first element of this lazy list with the smallest value measured by function `f` with respect to the ordering `cmp`.

Definition Classes
IterableOnceOps
118. def minOption[B >: A](implicit ord: math.Ordering[B]): Option[A]

Finds the smallest element.

Finds the smallest element.

Note: will not terminate for infinite-sized collections.

B

The type over which the ordering is defined.

ord

An ordering to be used for comparing elements.

returns

an option value containing the smallest element of this lazy list with respect to the ordering `ord`.

Definition Classes
IterableOnceOps
119. final def mkString

Displays all elements of this lazy list in a string.

Displays all elements of this lazy list in a string.

Delegates to addString, which can be overridden.

returns

a string representation of this lazy list. In the resulting string the string representations (w.r.t. the method `toString`) of all elements of this lazy list follow each other without any separator string.

Definition Classes
IterableOnceOps
Annotations
()
120. final def mkString(sep: String)

Displays all elements of this lazy list in a string using a separator string.

Displays all elements of this lazy list in a string using a separator string.

Delegates to addString, which can be overridden.

sep

the separator string.

returns

a string representation of this lazy list. In the resulting string the string representations (w.r.t. the method `toString`) of all elements of this lazy list are separated by the string `sep`.

Definition Classes
IterableOnceOps
Annotations
()
Example:
1. `List(1, 2, 3).mkString("|") = "1|2|3"`

121. final def mkString(start: String, sep: String, end: String)

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

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

Delegates to addString, which can be overridden.

start

the starting string.

sep

the separator string.

end

the ending string.

returns

a string representation of this lazy list. 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 lazy list are separated by the string `sep`.

Definition Classes
IterableOnceOps
Example:
1. `List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"`

122. final def ne(arg0: AnyRef)

Equivalent to `!(this eq that)`.

Equivalent to `!(this eq that)`.

returns

`true` if the argument is not a reference to the receiver object; `false` otherwise.

Definition Classes
AnyRef
123. def newSpecificBuilder: Builder[A, LazyList[A]]

returns

a strict builder for the same collection type. Note that in the case of lazy collections (e.g. scala.collection.View or scala.collection.immutable.LazyList), it is possible to implement this method but the resulting `Builder` will break laziness. As a consequence, operations should preferably be implemented with `fromSpecific` instead of this method.

Attributes
protected
Definition Classes
IterableFactoryDefaultsIterableOps
Note

When implementing a custom collection type and refining `C` to the new type, this method needs to be overridden (the compiler will issue an error otherwise). In the common case where `C =:= CC[A]`, this can be done by mixing in the scala.collection.IterableFactoryDefaults trait, which implements the method using iterableFactory.

,

As witnessed by the `@uncheckedVariance` annotation, using this method might be unsound. However, as long as the returned builder is only fed with `A` values taken from `this` instance, it is safe.

124. def nonEmpty

Tests whether the lazy list is not empty.

Tests whether the lazy list is not empty.

returns

`true` if the lazy list contains at least one element, `false` otherwise.

Definition Classes
IterableOnceOps
Annotations
()
125. final def notify(): Unit

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

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

Definition Classes
AnyRef
Annotations
()
Note

not specified by SLS as a member of AnyRef

126. final def notifyAll(): Unit

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

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

Definition Classes
AnyRef
Annotations
()
Note

not specified by SLS as a member of AnyRef

127. def occCounts[B](sq: collection.Seq[B]): mutable.Map[B, Int]
Attributes
protected[collection]
Definition Classes
SeqOps
128. def orElse[A1 <: Int, B1 >: A](that: PartialFunction[A1, B1]): PartialFunction[A1, B1]

Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.

Composes this partial function with a fallback partial function which gets applied where this partial function is not defined.

A1

the argument type of the fallback function

B1

the result type of the fallback function

that

the fallback function

returns

a partial function which has as domain the union of the domains of this partial function and `that`. The resulting partial function takes `x` to `this(x)` where `this` is defined, and to `that(x)` where it is not.

Definition Classes
PartialFunction
129. def padTo[B >: A](len: Int, elem: B): LazyList[B]

A copy of this lazy list with an element value appended until a given target length is reached.

A copy of this lazy list with an element value appended until a given target length is reached.

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned lazy list.

len

the target length

elem

returns

a new lazy list consisting of all elements of this lazy list followed by the minimal number of occurrences of `elem` so that the resulting collection has a length of at least `len`.

Definition Classes
LazyListSeqOps
130. def partition(p: (A) => Boolean): (LazyList[A], LazyList[A])

A pair of, first, all elements that satisfy predicate `p` and, second, all elements that do not.

A pair of, first, all elements that satisfy predicate `p` and, second, all elements that do not.

The two lazy list correspond to the result of filter and filterNot, respectively.

The default implementation provided here needs to traverse the collection twice. Strict collections have an overridden version of `partition` in `StrictOptimizedIterableOps`, which requires only a single traversal.

This method preserves laziness; elements are only evaluated individually as needed.

Definition Classes
LazyListIterableOps
131. def partitionMap[A1, A2](f: (A) => Either[A1, A2]): (LazyList[A1], LazyList[A2])

Applies a function `f` to each element of the lazy list and returns a pair of lazy lists: the first one made of those values returned by `f` that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

Applies a function `f` to each element of the lazy list and returns a pair of lazy lists: the first one made of those values returned by `f` that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

Example:

```val xs = `LazyList`(1, "one", 2, "two", 3, "three") partitionMap {
case i: Int => Left(i)
case s: String => Right(s)
}
// xs == (`LazyList`(1, 2, 3),
//        `LazyList`(one, two, three))```

This method preserves laziness; elements are only evaluated individually as needed.

A1

the element type of the first resulting collection

A2

the element type of the second resulting collection

f

the 'split function' mapping the elements of this lazy list to an scala.util.Either

returns

a pair of lazy lists: the first one made of those values returned by `f` that were wrapped in scala.util.Left, and the second one made of those wrapped in scala.util.Right.

Definition Classes
LazyListIterableOps
132. def patch[B >: A](from: Int, other: IterableOnce[B], replaced: Int): LazyList[B]

Produces a new lazy list where a slice of elements in this lazy list is replaced by another sequence.

Produces a new lazy list where a slice of elements in this lazy list is replaced by another sequence.

Patching at negative indices is the same as patching starting at 0. Patching at indices at or larger than the length of the original lazy list appends the patch to the end. If the `replaced` count would exceed the available elements, the difference in excess is ignored.

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned lazy list.

from

the index of the first replaced element

other

the replacement sequence

replaced

the number of elements to drop in the original lazy list

returns

a new lazy list consisting of all elements of this lazy list except that `replaced` elements starting from `from` are replaced by all the elements of `other`.

Definition Classes
LazyListSeqOps
133. def permutations: Iterator[LazyList[A]]

Iterates over distinct permutations of elements.

Iterates over distinct permutations of elements.

Note: Even when applied to a view or a lazy collection it will always force the elements.

returns

An Iterator which traverses the distinct permutations of this lazy list.

Definition Classes
SeqOps
Example:
1. ```Seq('a', 'b', 'b').permutations.foreach(println)
// List(a, b, b)
// List(b, a, b)
// List(b, b, a)```
134. def prepended[B >: A](elem: B): LazyList[B]

A copy of the lazy list with an element prepended.

A copy of the lazy list with an element prepended.

Also, the original lazy list is not modified, so you will want to capture the result.

Example:

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

scala> val y = 2 +: x
y: List[Int] = List(2, 1)

scala> println(x)
List(1)```

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned lazy list.

elem

the prepended element

returns

a new lazy list consisting of `value` followed by all elements of this lazy list.

Definition Classes
LazyListSeqOps
135. def prependedAll[B >: A](prefix: IterableOnce[B]): LazyList[B]

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

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.

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned collection.

prefix

the iterable to prepend.

returns

a new lazy list which contains all elements of `prefix` followed by all the elements of this lazy list.

Definition Classes
LazyListSeqOps
136. def product[B >: A](implicit num: math.Numeric[B]): B

Multiplies together the elements of this collection.

Multiplies together the elements of this collection.

The default implementation uses `reduce` for a known non-empty collection, `foldLeft` otherwise.

Note: will not terminate for infinite-sized collections.

B

the result type of the `*` operator.

num

an implicit parameter defining a set of numeric operations which includes the `*` operator to be used in forming the product.

returns

the product of all elements of this lazy list with respect to the `*` operator in `num`.

Definition Classes
IterableOnceOps
137. def reduce[B >: A](op: (B, B) => B): B

Applies the given binary operator `op` to all elements of this lazy list.

Applies the given binary operator `op` to all elements of this lazy list.

For each application of the operator, each operand is either an element of this lazy list or another such application of the operator. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.

If this collection is ordered, then for any application of the operator, the element(s) appearing in the left operand will precede those in the right.

Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

B

The type parameter for the binary operator, a supertype of `A`.

op

A binary operator; must be associative for the result to always be the same across runs.

returns

The result of applying `op` between all the elements if the lazy list is nonempty.

Definition Classes
IterableOnceOps
Exceptions thrown

`UnsupportedOperationException` if this lazy list is empty.

138. def reduceLeft[B >: A](f: (B, A) => B): B

LazyList specialization of reduceLeft which allows GC to collect along the way.

LazyList specialization of reduceLeft which allows GC to collect along the way.

B

The type of value being accumulated.

f

The operation to perform on successive elements of the `LazyList`.

returns

The accumulated value from successive applications of `f`.

Definition Classes
LazyListIterableOnceOps
139. def reduceLeftOption[B >: A](op: (B, A) => B): Option[B]

If this lazy list is nonempty, reduces it with the given binary operator `op`, going left to right.

If this lazy list is nonempty, reduces it with the given binary operator `op`, going left to right.

The behavior is the same as reduceLeft except that the value is `None` if the lazy list is empty. Each element appears exactly once in the computation.

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

Note: will not terminate for infinite-sized collections.

B

The result type of the binary operator, a supertype of `A`.

op

A binary operator.

returns

The result of reducing this lazy list with `op` going left to right if the lazy list is nonempty, inside a `Some`, and `None` otherwise.

Definition Classes
IterableOnceOps
140. def reduceOption[B >: A](op: (B, B) => B): Option[B]

If this lazy list is nonempty, reduces it with the given binary operator `op`.

If this lazy list is nonempty, reduces it with the given binary operator `op`.

The behavior is the same as reduce except that the value is `None` if the lazy list is empty. The order of applications of the operator is unspecified and may be nondeterministic. Each element appears exactly once in the computation.

Note: might return different results for different runs, unless either of the following conditions is met: (1) the operator is associative, and the underlying collection type is ordered; or (2) the operator is associative and commutative.

Note: will not terminate for infinite-sized collections.

B

A type parameter for the binary operator, a supertype of `A`.

op

A binary operator; must be associative for the result to always be the same across runs.

returns

The result of reducing this lazy list with `op` if the lazy list is nonempty, inside a `Some`, and `None` otherwise.

Definition Classes
IterableOnceOps
141. def reduceRight[B >: A](op: (A, B) => B): B

Applies the given binary operator `op` to all elements of this lazy list, going right to left.

Applies the given binary operator `op` to all elements of this lazy list, going right to left.

"Going right to left" only makes sense if this collection is ordered: then if `x1`, `x2`, ..., `xn` are the elements of this lazy list, the result is `op(x1, op(x2, op( ... op(xn-1, xn) ... )))`.

If this collection is not ordered, then for each application of the operator, each left operand is an element. In addition, the rightmost operand is the last element of this lazy list and each other right operand is itself an application of the operator. Each element appears exactly once in the computation.

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

Note: will not terminate for infinite-sized collections.

B

The result type of the binary operator, a supertype of `A`.

op

A binary operator.

returns

The result of applying `op` to all elements of this lazy list, going right to left.

Definition Classes
IterableOnceOps
Exceptions thrown

`UnsupportedOperationException` if this lazy list is empty.

142. def reduceRightOption[B >: A](op: (A, B) => B): Option[B]

If this lazy list is nonempty, reduces it with the given binary operator `op`, going right to left.

If this lazy list is nonempty, reduces it with the given binary operator `op`, going right to left.

The behavior is the same as reduceRight except that the value is `None` if the lazy list is empty. Each element appears exactly once in the computation.

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

Note: will not terminate for infinite-sized collections.

B

The result type of the binary operator, a supertype of `A`.

op

A binary operator.

returns

The result of reducing this lazy list with `op` going right to left if the lazy list is nonempty, inside a `Some`, and `None` otherwise.

Definition Classes
IterableOnceOps
143. def reverse: LazyList[A]

Returns a new lazy list with the elements of this lazy list in reverse order.

Returns a new lazy list with the elements of this lazy list in reverse order.

Note: will not terminate for infinite-sized collections.

Note: Even when applied to a view or a lazy collection it will always force the elements.

This method evaluates all elements of the collection.

returns

a new lazy list with all elements of this lazy list in reverse order.

Definition Classes
LazyListSeqOps
144. def reverseIterator: Iterator[A]

An iterator yielding the elements of this lazy list in reverse order.

An iterator yielding the elements of this lazy list in reverse order.

Note: will not terminate for infinite-sized collections.

Note: `xs.reverseIterator` is the same as `xs.reverse.iterator` but might be more efficient.

returns

an iterator yielding the elements of this lazy list in reverse order.

Definition Classes
SeqOps
145. def reversed
Attributes
protected
Definition Classes
IterableOnceOps
146. def runWith[U](action: (A) => U): (Int) => Boolean

Composes this partial function with an action function which gets applied to results of this partial function.

Composes this partial function with an action function which gets applied to results of this partial function. The action function is invoked only for its side effects; its result is ignored.

Note that expression `pf.runWith(action)(x)` is equivalent to

`if(pf isDefinedAt x) { action(pf(x)); true } else false`

except that `runWith` is implemented via `applyOrElse` and thus potentially more efficient. Using `runWith` avoids double evaluation of pattern matchers and guards for partial function literals.

action

the action function

returns

a function which maps arguments `x` to `isDefinedAt(x)`. The resulting function runs `action(this(x))` where `this` is defined.

Definition Classes
PartialFunction

`applyOrElse`.

147. def sameElements[B >: A](that: IterableOnce[B])

Tests whether the elements of this collection are the same (and in the same order) as those of `that`.

Tests whether the elements of this collection are the same (and in the same order) as those of `that`.

Definition Classes
LinearSeqOpsSeqOps
148. def scan[B >: A](z: B)(op: (B, B) => B): LazyList[B]

Computes a prefix scan of the elements of the collection.

Computes a prefix scan of the elements of the collection.

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

B

element type of the resulting collection

z

neutral element for the operator `op`

op

the associative operator for the scan

returns

a new lazy list containing the prefix scan of the elements in this lazy list

Definition Classes
IterableOps
149. def scanLeft[B](z: B)(op: (B, A) => B): LazyList[B]

Produces a lazy list containing cumulative results of applying the operator going left to right, including the initial value.

Produces a lazy list containing cumulative results of applying the operator going left to right, including the initial value.

Note: will not terminate for infinite-sized collections.

This method preserves laziness; elements are only evaluated individually as needed.

B

the type of the elements in the resulting collection

z

the initial value

op

the binary operator applied to the intermediate result and the element

returns

collection with intermediate results

Definition Classes
LazyListIterableOpsIterableOnceOps
150. def scanRight[B](z: B)(op: (A, B) => B): LazyList[B]

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

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-sized collections.

Note: Even when applied to a view or a lazy collection it will always force the elements.

Example:

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

the type of the elements in the resulting collection

z

the initial value

op

the binary operator applied to the intermediate result and the element

returns

collection with intermediate results

Definition Classes
IterableOps
151. def search[B >: A](elem: B, from: Int, to: Int)(implicit ord: Ordering[B])

Searches within an interval in this sorted sequence for a specific element.

Searches within an interval in this sorted sequence for a specific element. If this sequence is an `IndexedSeq`, a binary search is used. Otherwise, a linear search is used.

The sequence should be sorted with the same `Ordering` before calling; otherwise, the results are undefined.

elem

the element to find.

from

the index where the search starts.

to

the index following where the search ends.

ord

the ordering to be used to compare elements.

returns

a `Found` value containing the index corresponding to the element in the sequence, or the `InsertionPoint` where the element would be inserted if the element is not in the sequence.

Definition Classes
SeqOps
Note

if `to <= from`, the search space is empty, and an `InsertionPoint` at `from` is returned

scala.collection.IndexedSeq

scala.math.Ordering

scala.collection.SeqOps, method `sorted`

152. def search[B >: A](elem: B)(implicit ord: Ordering[B])

Searches this sorted sequence for a specific element.

Searches this sorted sequence for a specific element. If the sequence is an `IndexedSeq`, a binary search is used. Otherwise, a linear search is used.

The sequence should be sorted with the same `Ordering` before calling; otherwise, the results are undefined.

elem

the element to find.

ord

the ordering to be used to compare elements.

returns

a `Found` value containing the index corresponding to the element in the sequence, or the `InsertionPoint` where the element would be inserted if the element is not in the sequence.

Definition Classes
SeqOps

scala.collection.IndexedSeq

scala.math.Ordering

scala.collection.SeqOps, method `sorted`

153. def segmentLength(p: (A) => Boolean, from: Int): Int

Computes the length of the longest segment that starts from some index and whose elements all satisfy some predicate.

Computes the length of the longest segment that starts from some index and whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

from

the index where the search starts.

returns

the length of the longest segment of this lazy list starting from index `from` such that every element of the segment satisfies the predicate `p`.

Definition Classes
LinearSeqOpsSeqOps
154. final def segmentLength(p: (A) => Boolean): Int

Computes the length of the longest segment that starts from the first element and whose elements all satisfy some predicate.

Computes the length of the longest segment that starts from the first element and whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the length of the longest segment of this lazy list that starts from the first element such that every element of the segment satisfies the predicate `p`.

Definition Classes
SeqOps
155. final def size: Int

The size of this lazy list.

The size of this lazy list.

Note: will not terminate for infinite-sized collections.

returns

the number of elements in this lazy list.

Definition Classes
SeqOpsIterableOnceOps
156. final def sizeCompare(that: collection.Iterable[_]): Int

Compares the size of this lazy list to the size of another `Iterable`.

Compares the size of this lazy list to the size of another `Iterable`.

that

the `Iterable` whose size is compared with this lazy list's size.

returns

A value `x` where

```x <  0       if this.size <  that.size
x == 0       if this.size == that.size
x >  0       if this.size >  that.size```

The method as implemented here does not call `size` directly; its running time is `O(this.size min that.size)` instead of `O(this.size + that.size)`. The method should be overridden if computing `size` is cheap and `knownSize` returns `-1`.

Definition Classes
SeqOpsIterableOps
157. final def sizeCompare(otherSize: Int): Int

Compares the size of this lazy list to a test value.

Compares the size of this lazy list to a test value.

otherSize

the test value that gets compared with the size.

returns

A value `x` where

```x <  0       if this.size <  otherSize
x == 0       if this.size == otherSize
x >  0       if this.size >  otherSize```

The method as implemented here does not call `size` directly; its running time is `O(size min otherSize)` instead of `O(size)`. The method should be overridden if computing `size` is cheap and `knownSize` returns `-1`.

Definition Classes
SeqOpsIterableOps

sizeIs

158. final def sizeIs

Returns a value class containing operations for comparing the size of this lazy list to a test value.

Returns a value class containing operations for comparing the size of this lazy list to a test value.

These operations are implemented in terms of `sizeCompare(Int)`, and allow the following more readable usages:

```this.sizeIs < size     // this.sizeCompare(size) < 0
this.sizeIs <= size    // this.sizeCompare(size) <= 0
this.sizeIs == size    // this.sizeCompare(size) == 0
this.sizeIs != size    // this.sizeCompare(size) != 0
this.sizeIs >= size    // this.sizeCompare(size) >= 0
this.sizeIs > size     // this.sizeCompare(size) > 0```
Definition Classes
IterableOps
Annotations
()
159. def slice(from: Int, until: Int): LazyList[A]

Selects an interval of elements.

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

`from <= indexOf(x) < until`

This method does not evaluate anything until an operation is performed on the result (e.g. calling `head` or `tail`, or checking if it is empty). Additionally, it preserves laziness for all but the first `from` elements.

from

the lowest index to include from this lazy list.

until

the lowest index to EXCLUDE from this lazy list.

returns

a lazy list containing the elements greater than or equal to index `from` extending up to (but not including) index `until` of this lazy list.

Definition Classes
LazyListIterableOpsIterableOnceOps
160. def sliding(size: Int, step: Int): Iterator[LazyList[A]]

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`).

The returned iterator will be empty when called on an empty collection. The last element the iterator produces may be smaller than the window size when the original collection isn't exhausted by the window before it and its last element isn't skipped by the step before it.

The iterator returned by this method mostly preserves laziness; `size - step max 1` elements ahead of the iterator are evaluated.

size

the number of elements per group

step

the distance between the first elements of successive groups

returns

An iterator producing lazy lists of size `size`, except the last element (which may be the only element) will be smaller if there are fewer than `size` elements remaining to be grouped.

Definition Classes
LazyListIterableOps
161. def sliding(size: Int): Iterator[LazyList[A]]

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`).

An empty collection returns an empty iterator, and a non-empty collection containing fewer elements than the window size returns an iterator that will produce the original collection as its only element.

size

the number of elements per group

returns

An iterator producing lazy lists of size `size`, except for a non-empty collection with less than `size` elements, which returns an iterator that produces the source collection itself as its only element.

Definition Classes
IterableOps
Examples:
1. `List().sliding(2) = empty iterator`

2. ,
3. `List(1).sliding(2) = Iterator(List(1))`

4. ,
5. `List(1, 2).sliding(2) = Iterator(List(1, 2))`

6. ,
7. `List(1, 2, 3).sliding(2) = Iterator(List(1, 2), List(2, 3))`

scala.collection.Iterator, method `sliding`

162. def sortBy[B](f: (A) => B)(implicit ord: Ordering[B]): LazyList[A]

Sorts this lazy list according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.

Sorts this lazy list according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.

Note: will not terminate for infinite-sized collections.

Note: Even when applied to a view or a lazy collection it will always force the elements.

The sort is stable. That is, elements that are equal (as determined by `ord.compare`) appear in the same order in the sorted sequence as in the original.

B

the target type of the transformation `f`, and the type where the ordering `ord` is defined.

f

the transformation function mapping elements to some other domain `B`.

ord

the ordering assumed on domain `B`.

returns

a lazy list consisting of the elements of this lazy list sorted according to the ordering where `x < y` if `ord.lt(f(x), f(y))`.

Definition Classes
SeqOps
Example:
1. ```val words = "The quick brown fox jumped over the lazy dog".split(' ')
// this works because scala.Ordering will implicitly provide an Ordering[Tuple2[Int, Char]]
res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)```

scala.math.Ordering

163. def sortWith(lt: (A, A) => Boolean): LazyList[A]

Sorts this lazy list according to a comparison function.

Sorts this lazy list according to a comparison function.

Note: will not terminate for infinite-sized collections.

Note: Even when applied to a view or a lazy collection it will always force the elements.

The sort is stable. That is, elements that are equal (`lt` returns false for both directions of comparison) appear in the same order in the sorted sequence as in the original.

lt

a predicate that is true if its first argument strictly precedes its second argument in the desired ordering.

returns

a lazy list consisting of the elements of this lazy list sorted according to the comparison function `lt`.

Definition Classes
SeqOps
Example:
1. ```List("Steve", "Bobby", "Tom", "John", "Bob").sortWith((x, y) => x.take(3).compareTo(y.take(3)) < 0) =
List("Bobby", "Bob", "John", "Steve", "Tom")```
164. def sorted[B >: A](implicit ord: Ordering[B]): LazyList[A]

Sorts this lazy list according to an Ordering.

Sorts this lazy list according to an Ordering.

The sort is stable. That is, elements that are equal (as determined by `ord.compare`) appear in the same order in the sorted sequence as in the original.

ord

the ordering to be used to compare elements.

returns

a lazy list consisting of the elements of this lazy list sorted according to the ordering `ord`.

Definition Classes
SeqOps

scala.math.Ordering Note: Even when applied to a view or a lazy collection it will always force the elements.

165. def span(p: (A) => Boolean): (LazyList[A], LazyList[A])

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

Splits this lazy list 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.

p

the test predicate

returns

a pair consisting of the longest prefix of this lazy list whose elements all satisfy `p`, and the rest of this lazy list.

Definition Classes
IterableOpsIterableOnceOps
166. def splitAt(n: Int): (LazyList[A], LazyList[A])

Splits this lazy list into a prefix/suffix pair at a given position.

Splits this lazy list into a prefix/suffix pair at a given position.

Note: `c splitAt n` is equivalent to (but possibly more efficient than) `(c take n, c drop n)`.

n

the position at which to split.

returns

a pair of lazy lists consisting of the first `n` elements of this lazy list, and the other elements.

Definition Classes
IterableOpsIterableOnceOps
167. def startsWith[B >: A](that: IterableOnce[B], offset: Int = 0)

Tests whether this lazy list contains the given sequence at a given index.

Tests whether this lazy list contains the given sequence at a given index.

Note: If the both the receiver object `this` and the argument `that` are infinite sequences this method may not terminate.

that

the sequence to test

offset

the index where the sequence is searched.

returns

`true` if the sequence `that` is contained in this lazy list at index `offset`, otherwise `false`.

Definition Classes
SeqOps
168. def stepper[S <: Stepper[_]](implicit shape: StepperShape[A, S]): S

Returns a scala.collection.Stepper for the elements of this collection.

Returns a scala.collection.Stepper for the elements of this collection.

The Stepper enables creating a Java stream to operate on the collection, see scala.jdk.StreamConverters. For collections holding primitive values, the Stepper can be used as an iterator which doesn't box the elements.

The implicit scala.collection.StepperShape parameter defines the resulting Stepper type according to the element type of this collection.

Note that this method is overridden in subclasses and the return type is refined to `S with EfficientSplit`, for example scala.collection.IndexedSeqOps.stepper. For Steppers marked with scala.collection.Stepper.EfficientSplit, the converters in scala.jdk.StreamConverters allow creating parallel streams, whereas bare Steppers can be converted only to sequential streams.

Definition Classes
IterableOnce
169. def stringPrefix
Attributes
protected[this]
Definition Classes
LinearSeqSeqIterable
Annotations
()
170. def sum[B >: A](implicit num: math.Numeric[B]): B

Sums the elements of this collection.

Sums the elements of this collection.

The default implementation uses `reduce` for a known non-empty collection, `foldLeft` otherwise.

Note: will not terminate for infinite-sized collections.

B

the result type of the `+` operator.

num

an implicit parameter defining a set of numeric operations which includes the `+` operator to be used in forming the sum.

returns

the sum of all elements of this lazy list with respect to the `+` operator in `num`.

Definition Classes
IterableOnceOps
171. final def synchronized[T0](arg0: => T0): T0

Executes the code in `body` with an exclusive lock on `this`.

Executes the code in `body` with an exclusive lock on `this`.

returns

the result of `body`

Definition Classes
AnyRef
172. def tail: LazyList[A]

<invalid inheritdoc annotation>

<invalid inheritdoc annotation>

Note: *Must* be overridden in subclasses. The default implementation is inherited from IterableOps.

Definition Classes
LazyListLinearSeqOpsIterableOps
173. def tails: Iterator[LazyList[A]]

Iterates over the tails of this lazy list.

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

returns

an iterator over all the tails of this lazy list

Definition Classes
LinearSeqOpsIterableOps
Example:
1. `List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)`

174. def take(n: Int): LazyList[A]

Selects the first `n` elements.

Selects the first `n` elements.

This method preserves laziness; elements are only evaluated individually as needed.

n

the number of elements to take from this lazy list.

returns

a lazy list consisting only of the first `n` elements of this lazy list, or else the whole lazy list, if it has less than `n` elements. If `n` is negative, returns an empty lazy list.

Definition Classes
LazyListIterableOpsIterableOnceOps
175. def takeRight(n: Int): LazyList[A]

Selects the last n elements.

Selects the last n elements.

This method does not evaluate anything until an operation is performed on the result (e.g. calling `head` or `tail`, or checking if it is empty).

n

the number of elements to take from this lazy list.

returns

a lazy list consisting only of the last `n` elements of this lazy list, or else the whole lazy list, if it has less than `n` elements. If `n` is negative, returns an empty lazy list.

Definition Classes
LazyListIterableOps
176. def takeWhile(p: (A) => Boolean): LazyList[A]

Takes longest prefix of elements that satisfy a predicate.

Takes longest prefix of elements that satisfy a predicate.

This method preserves laziness; elements are only evaluated individually as needed.

p

The predicate used to test elements.

returns

the longest prefix of this lazy list whose elements all satisfy the predicate `p`.

Definition Classes
LazyListIterableOpsIterableOnceOps
177. def tapEach[U](f: (A) => U): LazyList[A]

Applies a side-effecting function to each element in this collection.

Applies a side-effecting function to each element in this collection. Strict collections will apply `f` to their elements immediately, while lazy collections like Views and LazyLists will only apply `f` on each element if and when that element is evaluated, and each time that element is evaluated.

This method preserves laziness; elements are only evaluated individually as needed.

U

the return type of f

f

a function to apply to each element in this lazy list

returns

The same logical collection as this

Definition Classes
LazyListIterableOpsIterableOnceOps
178. def to[C1](factory: Factory[A, C1]): C1

Given a collection factory `factory`, converts this lazy list to the appropriate representation for the current element type `A`.

Given a collection factory `factory`, converts this lazy list to the appropriate representation for the current element type `A`. Example uses:

```xs.to(List)
xs.to(ArrayBuffer)
xs.to(BitSet) // for xs: Iterable[Int]```
Definition Classes
IterableOnceOps
179. def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]

Converts this lazy list to an `Array`.

Converts this lazy list to an `Array`.

Implementation note: DO NOT call Array.from from this method.

B

The type of elements of the result, a supertype of `A`.

returns

This lazy list as an `Array[B]`.

Definition Classes
IterableOnceOps
180. final def toBuffer[B >: A]: Buffer[B]

Converts this lazy list to a `Buffer`.

Converts this lazy list to a `Buffer`.

B

The type of elements of the result, a supertype of `A`.

returns

This lazy list as a `Buffer[B]`.

Definition Classes
IterableOnceOps
Annotations
()
181. def toIndexedSeq: IndexedSeq[A]

Converts this lazy list to an `IndexedSeq`.

Converts this lazy list to an `IndexedSeq`.

returns

This lazy list as an `IndexedSeq[A]`.

Definition Classes
IterableOnceOps
182. def toList: List[A]

Converts this lazy list to a `List`.

Converts this lazy list to a `List`.

returns

This lazy list as a `List[A]`.

Definition Classes
IterableOnceOps
183. def toMap[K, V](implicit ev: <:<[A, (K, V)]): Map[K, V]

Converts this lazy list to a `Map`, given an implicit coercion from the lazy list's type to a key-value tuple.

Converts this lazy list to a `Map`, given an implicit coercion from the lazy list's type to a key-value tuple.

K

The key type for the resulting map.

V

The value type for the resulting map.

ev

An implicit coercion from `A` to `[K, V]`.

returns

This lazy list as a `Map[K, V]`.

Definition Classes
IterableOnceOps
184. final def toSeq: LazyList.this.type

returns

This lazy list as a `Seq[A]`. This is equivalent to `to(Seq)` but might be faster.

Definition Classes
SeqIterableOnceOps
185. def toSet[B >: A]: Set[B]

Converts this lazy list to a `Set`.

Converts this lazy list to a `Set`.

B

The type of elements of the result, a supertype of `A`.

returns

This lazy list as a `Set[B]`.

Definition Classes
IterableOnceOps
186. def toString()

This method preserves laziness; elements are only evaluated individually as needed.

This method preserves laziness; elements are only evaluated individually as needed.

returns

a string representation of this collection. An undefined state is represented with `"<not computed>"` and cycles are represented with `"<cycle>"` Examples:

• `"LazyList(4, <not computed>)"`, a non-empty lazy list ;
• `"LazyList(1, 2, 3, <not computed>)"`, a lazy list with at least three elements ;
• `"LazyList(1, 2, 3, <cycle>)"`, an infinite lazy list that contains a cycle at the fourth element.
Definition Classes
LazyListSeqFunction1Iterable → AnyRef → Any
187. def toVector: Vector[A]

Converts this lazy list to a `Vector`.

Converts this lazy list to a `Vector`.

returns

This lazy list as a `Vector[A]`.

Definition Classes
IterableOnceOps
188. def transpose[B](implicit asIterable: (A) => collection.Iterable[B]): LazyList[LazyList[B]]

Transposes this lazy list of iterable collections into a lazy list of lazy lists.

Transposes this lazy list of iterable collections into a lazy list of lazy lists.

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

```val xs = List(
Set(1, 2, 3),
Set(4, 5, 6)).transpose
// xs == List(
//         List(1, 4),
//         List(2, 5),
//         List(3, 6))

val ys = Vector(
List(1, 2, 3),
List(4, 5, 6)).transpose
// ys == Vector(
//         Vector(1, 4),
//         Vector(2, 5),
//         Vector(3, 6))```

Note: Even when applied to a view or a lazy collection it will always force the elements.

This method evaluates all elements of the collection.

B

the type of the elements of each iterable collection.

asIterable

an implicit conversion which asserts that the element type of this lazy list is an `Iterable`.

returns

a two-dimensional lazy list of lazy lists which has as nth row the nth column of this lazy list.

Definition Classes
LazyListIterableOps
189. def unapply(a: Int): Option[A]

Tries to extract a `B` from an `A` in a pattern matching expression.

Tries to extract a `B` from an `A` in a pattern matching expression.

Definition Classes
PartialFunction
190. def unlift: PartialFunction[Int, B]

Converts an optional function to a partial function.

Converts an optional function to a partial function.

Implicit
This member is added by an implicit conversion from LazyList[A] toUnliftOps[Int, B] performed by method UnliftOps in scala.Function1.This conversion will take place only if A is a subclass of Option[B] (A <: Option[B]).
Definition Classes
UnliftOps
Example:
1. Unlike Function.unlift, this UnliftOps.unlift method can be used in extractors.

```val of: Int => Option[String] = { i =>
if (i == 2) {
Some("matched by an optional function")
} else {
None
}
}

util.Random.nextInt(4) match {
case of.unlift(m) => // Convert an optional function to a pattern
println(m)
case _ =>
println("Not matched")
}```
191. def unzip[A1, A2](implicit asPair: (A) => (A1, A2)): (LazyList[A1], LazyList[A2])

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

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

```val xs = `LazyList`(
(1, "one"),
(2, "two"),
(3, "three")).unzip
// xs == (`LazyList`(1, 2, 3),
//        `LazyList`(one, two, three))```

This method preserves laziness; elements are only evaluated individually as needed.

A1

the type of the first half of the element pairs

A2

the type of the second half of the element pairs

asPair

an implicit conversion which asserts that the element type of this lazy list is a pair.

returns

a pair of lazy lists, containing the first, respectively second half of each element pair of this lazy list.

Definition Classes
LazyListIterableOps
192. def unzip3[A1, A2, A3](implicit asTriple: (A) => (A1, A2, A3)): (LazyList[A1], LazyList[A2], LazyList[A3])

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

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

```val xs = `LazyList`(
(1, "one", '1'),
(2, "two", '2'),
(3, "three", '3')).unzip3
// xs == (`LazyList`(1, 2, 3),
//        `LazyList`(one, two, three),
//        `LazyList`(1, 2, 3))```

This method preserves laziness; elements are only evaluated individually as needed.

A1

the type of the first member of the element triples

A2

the type of the second member of the element triples

A3

the type of the third member of the element triples

asTriple

an implicit conversion which asserts that the element type of this lazy list is a triple.

returns

a triple of lazy lists, containing the first, second, respectively third member of each element triple of this lazy list.

Definition Classes
LazyListIterableOps
193. def updated[B >: A](index: Int, elem: B): LazyList[B]

A copy of this lazy list with one single replaced element.

A copy of this lazy list with one single replaced element.

This method preserves laziness; elements are only evaluated individually as needed.

B

the element type of the returned lazy list.

index

the position of the replacement

elem

the replacing element

returns

a new lazy list which is a copy of this lazy list with the element at position `index` replaced by `elem`.

Definition Classes
LazyListSeqOps
194. def view: SeqView[A]

A view over the elements of this collection.

A view over the elements of this collection.

Definition Classes
SeqOpsIterableOps
195. final def wait(): Unit
Definition Classes
AnyRef
Annotations
(classOf[java.lang.InterruptedException])
Note

not specified by SLS as a member of AnyRef

196. final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
AnyRef
Annotations
(classOf[java.lang.InterruptedException])
Note

not specified by SLS as a member of AnyRef

197. final def wait(arg0: Long): Unit
Definition Classes
AnyRef
Annotations
(classOf[java.lang.InterruptedException]) ()
Note

not specified by SLS as a member of AnyRef

198. def withFilter(p: (A) => Boolean): WithFilter[A, LazyList]

A `collection.WithFilter` which allows GC of the head of lazy list during processing.

A `collection.WithFilter` which allows GC of the head of lazy list during processing.

This method is not particularly useful for a lazy list, as filter already preserves laziness.

The `collection.WithFilter` returned by this method preserves laziness; elements are only evaluated individually as needed.

p

the predicate used to test elements.

returns

an object of class `WithFilter`, which supports `map`, `flatMap`, `foreach`, and `withFilter` operations. All these operations apply to those elements of this lazy list which satisfy the predicate `p`.

Definition Classes
LazyListIterableOps
199. def writeReplace()
Attributes
protected[this]
200. def zip[B](that: IterableOnce[B]): LazyList[(A, B)]

Returns a lazy list formed from this lazy list and another iterable collection by combining corresponding elements in pairs.

Returns a lazy list formed from this lazy list 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.

This method preserves laziness; elements are only evaluated individually as needed.

B

the type of the second half of the returned pairs

that

The iterable providing the second half of each result pair

returns

a new lazy list containing pairs consisting of corresponding elements of this lazy list and `that`. The length of the returned collection is the minimum of the lengths of this lazy list and `that`.

Definition Classes
LazyListIterableOps
201. def zipAll[A1 >: A, B](that: collection.Iterable[B], thisElem: A1, thatElem: B): LazyList[(A1, B)]

Returns a lazy list formed from this lazy list and another iterable collection by combining corresponding elements in pairs.

Returns a lazy list formed from this lazy list 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.

This method preserves laziness; elements are only evaluated individually as needed.

that

the iterable providing the second half of each result pair

thisElem

the element to be used to fill up the result if this lazy list is shorter than `that`.

thatElem

the element to be used to fill up the result if `that` is shorter than this lazy list.

returns

a new collection of type `That` containing pairs consisting of corresponding elements of this lazy list and `that`. The length of the returned collection is the maximum of the lengths of this lazy list and `that`. If this lazy list is shorter than `that`, `thisElem` values are used to pad the result. If `that` is shorter than this lazy list, `thatElem` values are used to pad the result.

Definition Classes
LazyListIterableOps
202. def zipWithIndex: LazyList[(A, Int)]

Zips this lazy list with its indices.

Zips this lazy list with its indices.

This method preserves laziness; elements are only evaluated individually as needed.

returns

A new lazy list containing pairs consisting of all elements of this lazy list paired with their index. Indices start at `0`.

Definition Classes
LazyListIterableOpsIterableOnceOps

Deprecated Value Members

1. def /:[B](z: B)(op: (B, A) => B): B
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Definition Classes
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Annotations
()
Deprecated

(Since version 2.13.0) Use .iterator.foldLeft instead

2. final def /:[B](z: B)(op: (B, A) => B): B
Definition Classes
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Annotations
()
Deprecated

(Since version 2.13.0) Use foldLeft instead of /:

3. def :\[B](z: B)(op: (A, B) => B): B
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Definition Classes
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()
Deprecated

(Since version 2.13.0) Use .iterator.foldRight instead

4. final def :\[B](z: B)(op: (A, B) => B): B
Definition Classes
IterableOnceOps
Annotations
()
Deprecated

(Since version 2.13.0) Use foldRight instead of :\

5. def aggregate[B](z: => B)(seqop: (B, A) => B, combop: (B, B) => B): B

Aggregates the results of applying an operator to subsequent elements.

Aggregates the results of applying an operator to subsequent elements.

Since this method degenerates to `foldLeft` for sequential (non-parallel) collections, where the combining operation is ignored, it is advisable to prefer `foldLeft` for that case.

For parallel collections, use the `aggregate` method specified by `scala.collection.parallel.ParIterableLike`.

B

the result type, produced by `seqop`, `combop`, and by this function as a final result.

z

the start value, a neutral element for `seqop`.

seqop

the binary operator used to accumulate the result.

combop

an associative operator for combining sequential results, unused for sequential collections.

Definition Classes
IterableOnceOps
Annotations
Deprecated

(Since version 2.13.0) For sequential collections, prefer `foldLeft(z)(seqop)`. For parallel collections, use `ParIterableLike#aggregate`.

6. def collectFirst[B](f: PartialFunction[A, B]): Option[B]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Definition Classes
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.collectFirst(...) instead

7. def companion: IterableFactory[[_]LazyList[_]]
Definition Classes
IterableOps
Annotations
() ()
Deprecated

(Since version 2.13.0) Use iterableFactory instead

8. def copyToBuffer(dest: Buffer[A]): Unit
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Definition Classes
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.copyToBuffer(...) instead

9. final def copyToBuffer[B >: A](dest: Buffer[B]): Unit
Definition Classes
IterableOnceOps
Annotations
()
Deprecated

(Since version 2.13.0) Use `dest ++= coll` instead

10. def count(f: (A) => Boolean): Int
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.count(...) instead

11. def exists(f: (A) => Boolean)
Implicit
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.exists(...) instead

12. def filter(f: (A) => Boolean): Iterator[A]
Implicit
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13. def find(p: (A) => Boolean): Option[A]
Implicit
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Definition Classes
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.find instead

14. def flatMap[B](f: (A) => IterableOnce[B]): IterableOnce[B]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
This implicitly inherited member is shadowed by one or more members in this class.
To access this member you can use a type ascription:
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Definition Classes
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.flatMap instead or consider requiring an Iterable

15. def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Annotations
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(Since version 2.13.0) Use .iterator.fold instead

16. def foldLeft[B](z: B)(op: (B, A) => B): B
Implicit
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Annotations
()
Deprecated

(Since version 2.13.0) Use .iterator.foldLeft instead

17. def foldRight[B](z: B)(op: (A, B) => B): B
Implicit
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Annotations
()
Deprecated

(Since version 2.13.0) Use .iterator.foldRight instead

18. def forall(f: (A) => Boolean)
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.forall(...) instead

19. def foreach[U](f: (A) => U): Unit
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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()
Deprecated

(Since version 2.13.0) Use .iterator.foreach(...) instead

20. def formatted(fmtstr: String)

Returns string formatted according to given `format` string.

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

Implicit
This member is added by an implicit conversion from LazyList[A] toStringFormat[LazyList[A]] performed by method StringFormat in scala.Predef.
Definition Classes
StringFormat
Annotations
()
Deprecated

(Since version 2.12.16) Use `formatString.format(value)` instead of `value.formatted(formatString)`, or use the `f""` string interpolator. In Java 15 and later, `formatted` resolves to the new method in String which has reversed parameters.

21. def hasDefiniteSize

Tests whether this lazy list is known to have a finite size.

Tests whether this lazy list 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. Non-empty Iterators usually return `false` even if they were created from a collection with a known finite size.

Note: many collection methods will not work on collections of infinite sizes. The typical failure mode is an infinite loop. These methods always attempt a traversal without checking first that `hasDefiniteSize` returns `true`. However, checking `hasDefiniteSize` can provide an assurance that size is well-defined and non-termination is not a concern.

This method preserves laziness; elements are only evaluated individually as needed.

returns

`true` if this collection is known to have finite size, `false` otherwise.

Definition Classes
LazyListIterableOnceOps
Annotations
Deprecated

(Since version 2.13.0) Check .knownSize instead of .hasDefiniteSize for more actionable information (see scaladoc for details)

22. def isEmpty
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Annotations
Deprecated

(Since version 2.13.0) Use .iterator.isEmpty instead

23. def map[B](f: (A) => B): IterableOnce[B]
Implicit
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Deprecated

(Since version 2.13.0) Use .iterator.map instead or consider requiring an Iterable

24. def max(implicit ord: math.Ordering[A]): A
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.max instead

25. def maxBy[B](f: (A) => B)(implicit cmp: math.Ordering[B]): A
Implicit
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Deprecated

(Since version 2.13.0) Use .iterator.maxBy(...) instead

26. def min(implicit ord: math.Ordering[A]): A
Implicit
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Deprecated

(Since version 2.13.0) Use .iterator.min instead

27. def minBy[B](f: (A) => B)(implicit cmp: math.Ordering[B]): A
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.minBy(...) instead

28. def mkString
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.mkString instead

29. def mkString(sep: String)
Implicit
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30. def mkString(start: String, sep: String, end: String)
Implicit
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31. def nonEmpty
Implicit
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32. final def prefixLength(p: (A) => Boolean): Int

Returns the length of the longest prefix whose elements all satisfy some predicate.

Returns the length of the longest prefix whose elements all satisfy some predicate.

Note: may not terminate for infinite-sized collections.

p

the predicate used to test elements.

returns

the length of the longest prefix of this lazy list such that every element of the segment satisfies the predicate `p`.

Definition Classes
SeqOps
Annotations
()
Deprecated

(Since version 2.13.0) Use segmentLength instead of prefixLength

33. def product(implicit num: math.Numeric[A]): A
Implicit
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34. def reduce(f: (A, A) => A): A
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35. def reduceLeft(f: (A, A) => A): A
Implicit
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36. def reduceLeftOption(f: (A, A) => A): Option[A]
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37. def reduceOption(f: (A, A) => A): Option[A]
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38. def reduceRight(f: (A, A) => A): A
Implicit
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39. def reduceRightOption(f: (A, A) => A): Option[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.reduceRightOption(...) instead

40. final def repr: LazyList[A]
Definition Classes
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Deprecated

(Since version 2.13.0) Use coll instead of repr in a collection implementation, use the collection value itself from the outside

41. def reverseMap[B](f: (A) => B): LazyList[B]
Definition Classes
SeqOps
Annotations
Deprecated

(Since version 2.13.0) Use .reverseIterator.map(f).to(...) instead of .reverseMap(f)

42. def sameElements[B >: A](that: IterableOnce[B])
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.sameElements instead

43. def seq: LazyList.this.type
Definition Classes
Iterable
Annotations
Deprecated

(Since version 2.13.0) Iterable.seq always returns the iterable itself

44. def size: Int
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.size instead

45. def sum(implicit num: math.Numeric[A]): A
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.sum instead

46. def to[C1](factory: Factory[A, C1]): C1
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(factory) instead

47. def toArray[B >: A](implicit arg0: ClassTag[B]): Array[B]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.toArray

48. def toBuffer[B >: A]: Buffer[B]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(ArrayBuffer) instead

49. def toIndexedSeq
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.toIndexedSeq instead

50. final def toIterable
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(Iterable) instead

51. final def toIterable: LazyList.this.type

returns

This collection as an `Iterable[A]`. No new collection will be built if `this` is already an `Iterable[A]`.

Definition Classes
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Deprecated

(Since version 2.13.7) toIterable is internal and will be made protected; its name is similar to `toList` or `toSeq`, but it doesn't copy non-immutable collections

52. def toIterator: Iterator[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator instead

53. final def toIterator: Iterator[A]
Definition Classes
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()
Deprecated

(Since version 2.13.0) Use .iterator instead of .toIterator

54. def toList: List[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(List) instead

55. def toMap[K, V](implicit ev: <:<[A, (K, V)]): Map[K, V]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(Map) instead

56. def toSeq: Seq[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(Seq) instead

57. def toSet[B >: A]: Set[B]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.to(Set) instead

58. def toStream: Stream[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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(Since version 2.13.0) Use .iterator.to(LazyList) instead

59. final def toStream: Stream[A]
Definition Classes
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()
Deprecated

(Since version 2.13.0) Use .to(LazyList) instead of .toStream

60. final def toTraversable
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.to(Iterable) instead

61. final def toTraversable

Converts this lazy list to an unspecified Iterable.

Converts this lazy list to an unspecified Iterable. Will return the same collection if this instance is already Iterable.

returns

An Iterable containing all elements of this lazy list.

Definition Classes
IterableOps
Annotations
Deprecated

(Since version 2.13.0) toTraversable is internal and will be made protected; its name is similar to `toList` or `toSeq`, but it doesn't copy non-immutable collections

62. def toVector: Vector[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Deprecated

(Since version 2.13.0) Use .iterator.to(Vector) instead

63. final def union[B >: A](that: collection.Seq[B]): LazyList[B]

Produces a new sequence which contains all elements of this lazy list and also all elements of a given sequence.

Produces a new sequence which contains all elements of this lazy list and also all elements of a given sequence. `xs union ys` is equivalent to `xs ++ ys`.

B

the element type of the returned lazy list.

that

returns

a new collection which contains all elements of this lazy list followed by all elements of `that`.

Definition Classes
SeqOps
Annotations
()
Deprecated

(Since version 2.13.0) Use `concat` instead

64. def view(from: Int, until: Int): View[A]

A view over a slice of the elements of this collection.

A view over a slice of the elements of this collection.

Definition Classes
IterableOps
Annotations
Deprecated

(Since version 2.13.0) Use .view.slice(from, until) instead of .view(from, until)

65. def withFilter(f: (A) => Boolean): Iterator[A]
Implicit
This member is added by an implicit conversion from LazyList[A] toIterableOnceExtensionMethods[A] performed by method iterableOnceExtensionMethods in scala.collection.IterableOnce.
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Definition Classes
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(Since version 2.13.0) Use .iterator.withFilter(...) instead

66. def [B](y: B): (LazyList[A], B)
Implicit
This member is added by an implicit conversion from LazyList[A] toArrowAssoc[LazyList[A]] performed by method ArrowAssoc in scala.Predef.This conversion will take place only if A is a subclass of Option[Nothing] (A <: Option[Nothing]).
Definition Classes
ArrowAssoc
Annotations
Deprecated

(Since version 2.13.0) Use `->` instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.