final class NonEmptyList[+T] extends AnyVal
A non-empty list: an ordered, immutable, non-empty collection of elements with LinearSeq
performance characteristics.
The purpose of NonEmptyList
is to allow you to express in a type that a List
is non-empty, thereby eliminating the
need for (and potential exception from) a run-time check for non-emptiness. For a non-empty sequence with IndexedSeq
performance, see Every
.
Constructing NonEmptyList
s
You can construct a NonEmptyList
by passing one or more elements to the NonEmptyList.apply
factory method:
scala> NonEmptyList(1, 2, 3) res0: org.scalactic.anyvals.NonEmptyList[Int] = NonEmptyList(1, 2, 3)
Alternatively you can cons elements onto the End
singleton object, similar to making a List
starting with Nil
:
scala> 1 :: 2 :: 3 :: Nil res0: List[Int] = List(1, 2, 3) scala> 1 :: 2 :: 3 :: End res1: org.scalactic.NonEmptyList[Int] = NonEmptyList(1, 2, 3)
Note that although Nil
is a List[Nothing]
, End
is
not a NonEmptyList[Nothing]
, because no empty NonEmptyList
exists. (A non-empty list is a series
of connected links; if you have no links, you have no non-empty list.)
scala> val nil: List[Nothing] = Nil nil: List[Nothing] = List() scala> val nada: NonEmptyList[Nothing] = End <console>:16: error: type mismatch; found : org.scalactic.anyvals.End.type required: org.scalactic.anyvals.NonEmptyList[Nothing] val nada: NonEmptyList[Nothing] = End ^
Working with NonEmptyList
s
NonEmptyList
does not extend Scala's Seq
or Traversable
traits because these require that
implementations may be empty. For example, if you invoke tail
on a Seq
that contains just one element,
you'll get an empty Seq
:
scala> List(1).tail res6: List[Int] = List()
On the other hand, many useful methods exist on Seq
that when invoked on a non-empty Seq
are guaranteed
to not result in an empty Seq
. For convenience, NonEmptyList
defines a method corresponding to every such Seq
method. Here are some examples:
NonEmptyList(1, 2, 3).map(_ + 1) // Result: NonEmptyList(2, 3, 4) NonEmptyList(1).map(_ + 1) // Result: NonEmptyList(2) NonEmptyList(1, 2, 3).containsSlice(NonEmptyList(2, 3)) // Result: true NonEmptyList(1, 2, 3).containsSlice(NonEmptyList(3, 4)) // Result: false NonEmptyList(-1, -2, 3, 4, 5).minBy(_.abs) // Result: -1
NonEmptyList
does not currently define any methods corresponding to Seq
methods that could result in
an empty Seq
. However, an implicit converison from NonEmptyList
to List
is defined in the NonEmptyList
companion object that will be applied if you attempt to call one of the missing methods. As a
result, you can invoke filter
on an NonEmptyList
, even though filter
could result
in an empty sequence—but the result type will be List
instead of NonEmptyList
:
NonEmptyList(1, 2, 3).filter(_ < 10) // Result: List(1, 2, 3) NonEmptyList(1, 2, 3).filter(_ > 10) // Result: List()
You can use NonEmptyList
s in for
expressions. The result will be an NonEmptyList
unless
you use a filter (an if
clause). Because filters are desugared to invocations of filter
, the
result type will switch to a List
at that point. Here are some examples:
scala> import org.scalactic.anyvals._ import org.scalactic.anyvals._ scala> for (i <- NonEmptyList(1, 2, 3)) yield i + 1 res0: org.scalactic.anyvals.NonEmptyList[Int] = NonEmptyList(2, 3, 4) scala> for (i <- NonEmptyList(1, 2, 3) if i < 10) yield i + 1 res1: List[Int] = List(2, 3, 4) scala> for { | i <- NonEmptyList(1, 2, 3) | j <- NonEmptyList('a', 'b', 'c') | } yield (i, j) res3: org.scalactic.anyvals.NonEmptyList[(Int, Char)] = NonEmptyList((1,a), (1,b), (1,c), (2,a), (2,b), (2,c), (3,a), (3,b), (3,c)) scala> for { | i <- NonEmptyList(1, 2, 3) if i < 10 | j <- NonEmptyList('a', 'b', 'c') | } yield (i, j) res6: List[(Int, Char)] = List((1,a), (1,b), (1,c), (2,a), (2,b), (2,c), (3,a), (3,b), (3,c))
- T
the type of elements contained in this
NonEmptyList
- Alphabetic
- By Inheritance
- NonEmptyList
- AnyVal
- Any
- Hide All
- Show All
- Public
- All
Value Members
-
final
def
!=(arg0: Any): Boolean
- Definition Classes
- Any
-
final
def
##(): Int
- Definition Classes
- Any
-
def
++[U >: T](other: GenTraversableOnce[U]): NonEmptyList[U]
Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedGenTraversableOnce
.Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedGenTraversableOnce
. The element type of the resultingNonEmptyList
is the most specific superclass encompassing the element types of thisNonEmptyList
and the passedGenTraversableOnce
.- U
the element type of the returned
NonEmptyList
- other
the
GenTraversableOnce
to append- returns
a new
NonEmptyList
that contains all the elements of thisNonEmptyList
followed by all elements ofother
.
-
def
++[U >: T](other: Every[U]): NonEmptyList[U]
Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedEvery
.Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedEvery
. The element type of the resultingNonEmptyList
is the most specific superclass encompassing the element types of thisNonEmptyList
and the passedEvery
.- U
the element type of the returned
NonEmptyList
- other
the
Every
to append- returns
a new
NonEmptyList
that contains all the elements of thisNonEmptyList
followed by all elements ofother
.
-
def
++[U >: T](other: NonEmptyList[U]): NonEmptyList[U]
Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedNonEmptyList
.Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedNonEmptyList
. The element type of the resultingNonEmptyList
is the most specific superclass encompassing the element types of this and the passedNonEmptyList
.- U
the element type of the returned
NonEmptyList
- other
the
NonEmptyList
to append- returns
a new
NonEmptyList
that contains all the elements of thisNonEmptyList
followed by all elements ofother
.
-
final
def
+:[U >: T](element: U): NonEmptyList[U]
Returns a new
NonEmptyList
with the given element prepended.Returns a new
NonEmptyList
with the given element prepended.Note that :-ending operators are right associative. A mnemonic for
+:
vs.:+
is: the COLon goes on the COLlection side.- element
the element to prepend to this
NonEmptyList
- returns
a new
NonEmptyList
consisting ofelement
followed by all elements of thisNonEmptyList
.
-
final
def
/:[B](z: B)(op: (B, T) ⇒ B): B
Fold left: applies a binary operator to a start value,
z
, and all elements of thisNonEmptyList
, going left to right.Fold left: applies a binary operator to a start value,
z
, and all elements of thisNonEmptyList
, going left to right.Note:
/:
is alternate syntax for thefoldLeft
method;z
/:
non-empty list
is the same asnon-empty list
foldLeft
z
.- B
the result of the binary operator
- z
the start value
- op
the binary operator
- returns
the result of inserting
op
between consecutive elements of thisNonEmptyList
, going left to right, with the start value,z
, on the left:op(...op(op(z, x_1), x_2), ..., x_n)
where x1, ..., xn are the elements of thisNonEmptyList
.
-
def
:+[U >: T](element: U): NonEmptyList[U]
Returns a new
NonEmptyList
with the given element appended.Returns a new
NonEmptyList
with the given element appended.Note a mnemonic for
+:
vs.:+
is: the COLon goes on the COLlection side.- element
the element to append to this
NonEmptyList
- returns
a new
NonEmptyList
consisting of all elements of thisNonEmptyList
followed byelement
.
-
final
def
::[U >: T](element: U): NonEmptyList[U]
Adds an element to the beginning of this
NonEmptyList
.Adds an element to the beginning of this
NonEmptyList
.Note that :-ending operators are right associative. A mnemonic for
+:
vs.:+
is: the COLon goes on the COLlection side.- element
the element to prepend to this
NonEmptyList
- returns
a
NonEmptyList
that containselement
as first element and that continues with thisNonEmptyList
.
-
def
:::[U >: T](other: GenTraversableOnce[U]): NonEmptyList[U]
Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedGenTraversableOnce
.Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedGenTraversableOnce
. The element type of the resultingNonEmptyList
is the most specific superclass encompassing the element types of thisNonEmptyList
and the passedGenTraversableOnce
.- U
the element type of the returned
NonEmptyList
- other
the
GenTraversableOnce
to append- returns
a new
NonEmptyList
that contains all the elements of thisNonEmptyList
followed by all elements ofother
.
-
def
:::[U >: T](other: Every[U]): NonEmptyList[U]
Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedEvery
.Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedEvery
. The element type of the resultingNonEmptyList
is the most specific superclass encompassing the element types of this and the passedEvery
.- U
the element type of the returned
NonEmptyList
- other
the
Every
to append- returns
a new
NonEmptyList
that contains all the elements of thisNonEmptyList
followed by all elements ofother
.
-
def
:::[U >: T](other: NonEmptyList[U]): NonEmptyList[U]
Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedNonEmptyList
.Returns a new
NonEmptyList
containing the elements of thisNonEmptyList
followed by the elements of the passedNonEmptyList
. The element type of the resultingNonEmptyList
is the most specific superclass encompassing the element types of this and the passedNonEmptyList
.- U
the element type of the returned
NonEmptyList
- other
the
NonEmptyList
to append- returns
a new
NonEmptyList
that contains all the elements of thisNonEmptyList
followed by all elements ofother
.
-
final
def
:\[B](z: B)(op: (T, B) ⇒ B): B
Fold right: applies a binary operator to all elements of this
NonEmptyList
and a start value, going right to left.Fold right: applies a binary operator to all elements of this
NonEmptyList
and a start value, going right to left.Note:
:\
is alternate syntax for thefoldRight
method;non-empty list
:\
z
is the same asnon-empty list
foldRight
z
.- B
the result of the binary operator
- z
the start value
- op
the binary operator
- returns
the result of inserting
op
between consecutive elements of thisNonEmptyList
, going right to left, with the start value,z
, on the right:op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn are the elements of thisNonEmptyList
.
-
final
def
==(arg0: Any): Boolean
- Definition Classes
- Any
-
final
def
addString(sb: StringBuilder, start: String, sep: String, end: String): StringBuilder
Appends all elements of this
NonEmptyList
to a string builder using start, end, and separator strings.Appends all elements of this
NonEmptyList
to a string builder using start, end, and separator strings. The written text will consist of a concatenation of the stringstart
; the result of invokingtoString
on all elements of thisNonEmptyList
, separated by the stringsep
; and the stringend
- sb
the string builder to which elements will be appended
- start
the ending string
- sep
the separator string
- returns
the string builder,
sb
, to which elements were appended.
-
final
def
addString(sb: StringBuilder, sep: String): StringBuilder
Appends all elements of this
NonEmptyList
to a string builder using a separator string.Appends all elements of this
NonEmptyList
to a string builder using a separator string. The written text will consist of a concatenation of the result of invokingtoString
on of every element of thisNonEmptyList
, separated by the stringsep
.- sb
the string builder to which elements will be appended
- sep
the separator string
- returns
the string builder,
sb
, to which elements were appended.
-
final
def
addString(sb: StringBuilder): StringBuilder
Appends all elements of this
NonEmptyList
to a string builder.Appends all elements of this
NonEmptyList
to a string builder. The written text will consist of a concatenation of the result of invokingtoString
on of every element of thisNonEmptyList
, without any separator string.- sb
the string builder to which elements will be appended
- returns
the string builder,
sb
, to which elements were appended.
-
final
def
apply(idx: Int): T
Selects an element by its index in the
NonEmptyList
.Selects an element by its index in the
NonEmptyList
.- returns
the element of this
NonEmptyList
at indexidx
, where 0 indicates the first element.
-
final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
final
def
collectFirst[U](pf: PartialFunction[T, U]): Option[U]
Finds the first element of this
NonEmptyList
for which the given partial function is defined, if any, and applies the partial function to it.Finds the first element of this
NonEmptyList
for which the given partial function is defined, if any, and applies the partial function to it.- pf
the partial function
- returns
an
Option
containingpf
applied to the first element for which it is defined, orNone
if the partial function was not defined for any element.
-
final
def
contains(elem: Any): Boolean
Indicates whether this
NonEmptyList
contains a given value as an element.Indicates whether this
NonEmptyList
contains a given value as an element.- elem
the element to look for
- returns
true if this
NonEmptyList
has an element that is equal (as determined by==)
toelem
, false otherwise.
-
final
def
containsSlice[B](that: NonEmptyList[B]): Boolean
Indicates whether this
NonEmptyList
contains a givenNonEmptyList
as a slice.Indicates whether this
NonEmptyList
contains a givenNonEmptyList
as a slice.- that
the
NonEmptyList
slice to look for- returns
true if this
NonEmptyList
contains a slice with the same elements asthat
, otherwisefalse
.
-
final
def
containsSlice[B](that: Every[B]): Boolean
Indicates whether this
NonEmptyList
contains a givenEvery
as a slice.Indicates whether this
NonEmptyList
contains a givenEvery
as a slice.- that
the
Every
slice to look for- returns
true if this
NonEmptyList
contains a slice with the same elements asthat
, otherwisefalse
.
-
final
def
containsSlice[B](that: GenSeq[B]): Boolean
Indicates whether this
NonEmptyList
contains a givenGenSeq
as a slice.Indicates whether this
NonEmptyList
contains a givenGenSeq
as a slice.- that
the
GenSeq
slice to look for- returns
true if this
NonEmptyList
contains a slice with the same elements asthat
, otherwisefalse
.
-
final
def
copyToArray[U >: T](arr: Array[U], start: Int, len: Int): Unit
Copies values of this
NonEmptyList
to an array.Copies values of this
NonEmptyList
to an array. Fills the given arrayarr
with at mostlen
elements of thisNonEmptyList
, beginning at indexstart
. Copying will stop once either the end of the currentNonEmptyList
is reached, the end of the array is reached, orlen
elements have been copied.- arr
the array to fill
- start
the starting index
- len
the maximum number of elements to copy
-
final
def
copyToArray[U >: T](arr: Array[U], start: Int): Unit
Copies values of this
NonEmptyList
to an array.Copies values of this
NonEmptyList
to an array. Fills the given arrayarr
with values of thisNonEmptyList
, beginning at indexstart
. Copying will stop once either the end of the currentNonEmptyList
is reached, or the end of the array is reached.- arr
the array to fill
- start
the starting index
-
final
def
copyToArray[U >: T](arr: Array[U]): Unit
Copies values of this
NonEmptyList
to an array.Copies values of this
NonEmptyList
to an array. Fills the given arrayarr
with values of thisNonEmptyList
. Copying will stop once either the end of the currentNonEmptyList
is reached, or the end of the array is reached.- arr
the array to fill
-
final
def
copyToBuffer[U >: T](buf: Buffer[U]): Unit
Copies all elements of this
NonEmptyList
to a buffer.Copies all elements of this
NonEmptyList
to a buffer.- buf
the buffer to which elements are copied
-
final
def
corresponds[B](that: NonEmptyList[B])(p: (T, B) ⇒ Boolean): Boolean
Indicates whether every element of this
NonEmptyList
relates to the corresponding element of a givenNonEmptyList
by satisfying a given predicate.Indicates whether every element of this
NonEmptyList
relates to the corresponding element of a givenNonEmptyList
by satisfying a given predicate.- B
the type of the elements of
that
- that
the
NonEmptyList
to compare for correspondence- p
the predicate, which relates elements from this and the passed
NonEmptyList
- returns
true if this and the passed
NonEmptyList
have the same length andp(x, y)
istrue
for all corresponding elementsx
of thisNonEmptyList
andy
of that, otherwisefalse
.
-
final
def
corresponds[B](that: Every[B])(p: (T, B) ⇒ Boolean): Boolean
Indicates whether every element of this
NonEmptyList
relates to the corresponding element of a givenEvery
by satisfying a given predicate.Indicates whether every element of this
NonEmptyList
relates to the corresponding element of a givenEvery
by satisfying a given predicate.- B
the type of the elements of
that
- that
the
Every
to compare for correspondence- p
the predicate, which relates elements from this
NonEmptyList
and the passedEvery
- returns
true if this
NonEmptyList
and the passedEvery
have the same length andp(x, y)
istrue
for all corresponding elementsx
of thisNonEmptyList
andy
of that, otherwisefalse
.
-
final
def
corresponds[B](that: GenSeq[B])(p: (T, B) ⇒ Boolean): Boolean
Indicates whether every element of this
NonEmptyList
relates to the corresponding element of a givenGenSeq
by satisfying a given predicate.Indicates whether every element of this
NonEmptyList
relates to the corresponding element of a givenGenSeq
by satisfying a given predicate.- B
the type of the elements of
that
- that
the
GenSeq
to compare for correspondence- p
the predicate, which relates elements from this
NonEmptyList
and the passedGenSeq
- returns
true if this
NonEmptyList
and the passedGenSeq
have the same length andp(x, y)
istrue
for all corresponding elementsx
of thisNonEmptyList
andy
of that, otherwisefalse
.
-
final
def
count(p: (T) ⇒ Boolean): Int
Counts the number of elements in this
NonEmptyList
that satisfy a predicate.Counts the number of elements in this
NonEmptyList
that satisfy a predicate.- p
the predicate used to test elements.
- returns
the number of elements satisfying the predicate
p
.
-
final
def
distinct: NonEmptyList[T]
Builds a new
NonEmptyList
from thisNonEmptyList
without any duplicate elements.Builds a new
NonEmptyList
from thisNonEmptyList
without any duplicate elements.- returns
A new
NonEmptyList
that contains the first occurrence of every element of thisNonEmptyList
.
-
final
def
endsWith[B](that: NonEmptyList[B]): Boolean
Indicates whether this
NonEmptyList
ends with the givenNonEmptyList
.Indicates whether this
NonEmptyList
ends with the givenNonEmptyList
.- that
the
NonEmptyList
to test- returns
true
if thisNonEmptyList
hasthat
as a suffix,false
otherwise.
-
final
def
endsWith[B](that: Every[B]): Boolean
Indicates whether this
NonEmptyList
ends with the givenEvery
.Indicates whether this
NonEmptyList
ends with the givenEvery
.- that
the
Every
to test- returns
true
if thisNonEmptyList
hasthat
as a suffix,false
otherwise.
-
final
def
endsWith[B](that: GenSeq[B]): Boolean
Indicates whether this
NonEmptyList
ends with the givenGenSeq
.Indicates whether this
NonEmptyList
ends with the givenGenSeq
.- that
the sequence to test
- returns
true
if thisNonEmptyList
hasthat
as a suffix,false
otherwise.
-
final
def
exists(p: (T) ⇒ Boolean): Boolean
Indicates whether a predicate holds for at least one of the elements of this
NonEmptyList
.Indicates whether a predicate holds for at least one of the elements of this
NonEmptyList
.- returns
true
if the given predicatep
holds for some of the elements of thisNonEmptyList
, otherwisefalse
.
-
final
def
find(p: (T) ⇒ Boolean): Option[T]
Finds the first element of this
NonEmptyList
that satisfies the given predicate, if any.Finds the first element of this
NonEmptyList
that satisfies the given predicate, if any.- p
the predicate used to test elements
- returns
an
Some
containing the first element in thisNonEmptyList
that satisfiesp
, orNone
if none exists.
-
final
def
flatMap[U](f: (T) ⇒ NonEmptyList[U]): NonEmptyList[U]
Builds a new
NonEmptyList
by applying a function to all elements of thisNonEmptyList
and using the elements of the resultingNonEmptyList
s.Builds a new
NonEmptyList
by applying a function to all elements of thisNonEmptyList
and using the elements of the resultingNonEmptyList
s.- U
the element type of the returned
NonEmptyList
- f
the function to apply to each element.
- returns
a new
NonEmptyList
containing elements obtained by applying the given functionf
to each element of thisNonEmptyList
and concatenating the elements of resultingNonEmptyList
s.
-
final
def
flatten[B](implicit ev: <:<[T, NonEmptyList[B]]): NonEmptyList[B]
Converts this
NonEmptyList
ofNonEmptyList
s into aNonEmptyList
formed by the elements of the nestedNonEmptyList
s.Converts this
NonEmptyList
ofNonEmptyList
s into aNonEmptyList
formed by the elements of the nestedNonEmptyList
s.Note: You cannot use this
flatten
method on aNonEmptyList
that contains aGenTraversableOnce
s, because if all the nestedGenTraversableOnce
s were empty, you'd end up with an emptyNonEmptyList
.- returns
a new
NonEmptyList
resulting from concatenating all nestedNonEmptyList
s.
-
final
def
fold[U >: T](z: U)(op: (U, U) ⇒ U): U
Folds the elements of this
NonEmptyList
using the specified associative binary operator.Folds the elements of this
NonEmptyList
using the specified associative binary operator.The order in which operations are performed on elements is unspecified and may be nondeterministic.
- U
a type parameter for the binary operator, a supertype of T.
- z
a neutral element for the fold operation; may be added to the result an arbitrary number of times, and must not change the result (e.g.,
Nil
for list concatenation, 0 for addition, or 1 for multiplication.)- op
a binary operator that must be associative
- returns
the result of applying fold operator
op
between all the elements andz
-
final
def
foldLeft[B](z: B)(op: (B, T) ⇒ B): B
Applies a binary operator to a start value and all elements of this
NonEmptyList
, going left to right.Applies a binary operator to a start value and all elements of this
NonEmptyList
, going left to right.- B
the result type of the binary operator.
- z
the start value.
- op
the binary operator.
- returns
the result of inserting
op
between consecutive elements of thisNonEmptyList
, going left to right, with the start value,z
, on the left:op(...op(op(z, x_1), x_2), ..., x_n)
where x1, ..., xn are the elements of thisNonEmptyList
.
-
final
def
foldRight[B](z: B)(op: (T, B) ⇒ B): B
Applies a binary operator to all elements of this
NonEmptyList
and a start value, going right to left.Applies a binary operator to all elements of this
NonEmptyList
and a start value, going right to left.- B
the result of the binary operator
- z
the start value
- op
the binary operator
- returns
the result of inserting
op
between consecutive elements of thisNonEmptyList
, going right to left, with the start value,z
, on the right:op(x_1, op(x_2, ... op(x_n, z)...))
where x1, ..., xn are the elements of thisNonEmptyList
.
-
final
def
forall(p: (T) ⇒ Boolean): Boolean
Indicates whether a predicate holds for all elements of this
NonEmptyList
.Indicates whether a predicate holds for all elements of this
NonEmptyList
.- p
the predicate used to test elements.
- returns
true
if the given predicatep
holds for all elements of thisNonEmptyList
, otherwisefalse
.
-
final
def
foreach(f: (T) ⇒ Unit): Unit
Applies a function
f
to all elements of thisNonEmptyList
.Applies a function
f
to all elements of thisNonEmptyList
.- f
the function that is applied for its side-effect to every element. The result of function
f
is discarded.
-
def
getClass(): Class[_ <: AnyVal]
- Definition Classes
- AnyVal → Any
-
final
def
groupBy[K](f: (T) ⇒ K): Map[K, NonEmptyList[T]]
Partitions this
NonEmptyList
into a map ofNonEmptyList
s according to some discriminator function.Partitions this
NonEmptyList
into a map ofNonEmptyList
s according to some discriminator function.- K
the type of keys returned by the discriminator function.
- f
the discriminator function.
- returns
A map from keys to
NonEmptyList
s such that the following invariant holds:(nonEmptyList.toList partition f)(k) = xs filter (x => f(x) == k)
That is, every keyk
is bound to aNonEmptyList
of those elementsx
for whichf(x)
equalsk
.
-
final
def
grouped(size: Int): Iterator[NonEmptyList[T]]
Partitions elements into fixed size
NonEmptyList
s.Partitions elements into fixed size
NonEmptyList
s.- size
the number of elements per group
- returns
An iterator producing
NonEmptyList
s of sizesize
, except the last will be truncated if the elements don't divide evenly.
-
final
def
hasDefiniteSize: Boolean
Returns
true
to indicate thisNonEmptyList
has a definite size, since allNonEmptyList
s are strict collections. -
final
def
head: T
Selects the first element of this
NonEmptyList
.Selects the first element of this
NonEmptyList
.- returns
the first element of this
NonEmptyList
.
-
final
def
headOption: Option[T]
Selects the first element of this
NonEmptyList
and returns it wrapped in aSome
.Selects the first element of this
NonEmptyList
and returns it wrapped in aSome
.- returns
the first element of this
NonEmptyList
, wrapped in aSome
.
-
final
def
indexOf[U >: T](elem: U, from: Int): Int
Finds index of first occurrence of some value in this
NonEmptyList
after or at some start index.Finds index of first occurrence of some value in this
NonEmptyList
after or at some start index.- elem
the element value to search for.
- from
the start index
- returns
the index
>=
from
of the first element of thisNonEmptyList
that is equal (as determined by==
) toelem
, or-1
, if none exists.
-
final
def
indexOf[U >: T](elem: U): Int
Finds index of first occurrence of some value in this
NonEmptyList
.Finds index of first occurrence of some value in this
NonEmptyList
.- elem
the element value to search for.
- returns
the index of the first element of this
NonEmptyList
that is equal (as determined by==
) toelem
, or-1
, if none exists.
-
final
def
indexOfSlice[U >: T](that: NonEmptyList[U], from: Int): Int
Finds first index after or at a start index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.Finds first index after or at a start index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.- that
the
NonEmptyList
defining the slice to look for- from
the start index
- returns
the first index
>=
from
such that the elements of thisNonEmptyList
starting at this index match the elements ofNonEmptyList
that
, or-1
of no such subsequence exists.
-
final
def
indexOfSlice[U >: T](that: Every[U], from: Int): Int
Finds first index after or at a start index where this
NonEmptyList
contains a givenEvery
as a slice.Finds first index after or at a start index where this
NonEmptyList
contains a givenEvery
as a slice.- that
the
Every
defining the slice to look for- from
the start index
- returns
the first index
>=
from
such that the elements of thisNonEmptyList
starting at this index match the elements ofEvery
that
, or-1
of no such subsequence exists.
-
final
def
indexOfSlice[U >: T](that: NonEmptyList[U]): Int
Finds first index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.Finds first index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.- that
the
NonEmptyList
defining the slice to look for- returns
the first index such that the elements of this
NonEmptyList
starting at this index match the elements ofNonEmptyList
that
, or-1
of no such subsequence exists.
-
final
def
indexOfSlice[U >: T](that: Every[U]): Int
Finds first index where this
NonEmptyList
contains a givenEvery
as a slice.Finds first index where this
NonEmptyList
contains a givenEvery
as a slice.- that
the
Every
defining the slice to look for- returns
the first index such that the elements of this
NonEmptyList
starting at this index match the elements ofEvery
that
, or-1
of no such subsequence exists.
-
final
def
indexOfSlice[U >: T](that: GenSeq[U], from: Int): Int
Finds first index after or at a start index where this
NonEmptyList
contains a givenGenSeq
as a slice.Finds first index after or at a start index where this
NonEmptyList
contains a givenGenSeq
as a slice.- that
the
GenSeq
defining the slice to look for- from
the start index
- returns
the first index
>=
from
at which the elements of thisNonEmptyList
starting at that index match the elements ofGenSeq
that
, or-1
of no such subsequence exists.
-
final
def
indexOfSlice[U >: T](that: GenSeq[U]): Int
Finds first index where this
NonEmptyList
contains a givenGenSeq
as a slice.Finds first index where this
NonEmptyList
contains a givenGenSeq
as a slice.- that
the
GenSeq
defining the slice to look for- returns
the first index at which the elements of this
NonEmptyList
starting at that index match the elements ofGenSeq
that
, or-1
of no such subsequence exists.
-
final
def
indexWhere(p: (T) ⇒ 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.
- p
the predicate used to test elements.
- from
the start index
- returns
the index
>=
from
of the first element of thisNonEmptyList
that satisfies the predicatep
, or-1
, if none exists.
-
final
def
indexWhere(p: (T) ⇒ Boolean): Int
Finds index of the first element satisfying some predicate.
Finds index of the first element satisfying some predicate.
- p
the predicate used to test elements.
- returns
the index of the first element of this
NonEmptyList
that satisfies the predicatep
, or-1
, if none exists.
-
final
def
indices: Range
Produces the range of all indices of this
NonEmptyList
.Produces the range of all indices of this
NonEmptyList
.- returns
a
Range
value from0
to one less than the length of thisNonEmptyList
.
-
final
def
isDefinedAt(idx: Int): Boolean
Tests whether this
NonEmptyList
contains given index.Tests whether this
NonEmptyList
contains given index.- idx
the index to test
- returns
true if this
NonEmptyList
contains an element at positionidx
,false
otherwise.
-
final
def
isEmpty: Boolean
Returns
false
to indicate thisNonEmptyList
, like allNonEmptyList
s, is non-empty.
Returns
false
to indicate thisNonEmptyList
, like allNonEmptyList
s, is non-empty.
- returns
false
-
final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
final
def
isTraversableAgain: Boolean
Returns
true
to indicate thisNonEmptyList
, like allNonEmptyList
s, can be traversed repeatedly.Returns
true
to indicate thisNonEmptyList
, like allNonEmptyList
s, can be traversed repeatedly.- returns
true
-
final
def
iterator: Iterator[T]
Creates and returns a new iterator over all elements contained in this
NonEmptyList
.Creates and returns a new iterator over all elements contained in this
NonEmptyList
.- returns
the new iterator
-
final
def
last: T
Selects the last element of this
NonEmptyList
.Selects the last element of this
NonEmptyList
.- returns
the last element of this
NonEmptyList
.
-
final
def
lastIndexOf[U >: T](elem: U, end: Int): Int
Finds the index of the last occurrence of some value in this
NonEmptyList
before or at a givenend
index.Finds the index of the last occurrence of some value in this
NonEmptyList
before or at a givenend
index.- elem
the element value to search for.
- end
the end index.
- returns
the index
>=
end
of the last element of thisNonEmptyList
that is equal (as determined by==
) toelem
, or-1
, if none exists.
-
final
def
lastIndexOf[U >: T](elem: U): Int
Finds the index of the last occurrence of some value in this
NonEmptyList
.Finds the index of the last occurrence of some value in this
NonEmptyList
.- elem
the element value to search for.
- returns
the index of the last element of this
NonEmptyList
that is equal (as determined by==
) toelem
, or-1
, if none exists.
-
final
def
lastIndexOfSlice[U >: T](that: NonEmptyList[U], end: Int): Int
Finds the last index before or at a given end index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.Finds the last index before or at a given end index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.- that
the
NonEmptyList
defining the slice to look for- end
the end index
- returns
the last index
>=
end
at which the elements of thisNonEmptyList
starting at that index match the elements ofNonEmptyList
that
, or-1
of no such subsequence exists.
-
final
def
lastIndexOfSlice[U >: T](that: Every[U], end: Int): Int
Finds the last index before or at a given end index where this
NonEmptyList
contains a givenEvery
as a slice.Finds the last index before or at a given end index where this
NonEmptyList
contains a givenEvery
as a slice.- that
the
Every
defining the slice to look for- end
the end index
- returns
the last index
>=
end
at which the elements of thisNonEmptyList
starting at that index match the elements ofEvery
that
, or-1
of no such subsequence exists.
-
final
def
lastIndexOfSlice[U >: T](that: NonEmptyList[U]): Int
Finds the last index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.Finds the last index where this
NonEmptyList
contains a givenNonEmptyList
as a slice.- that
the
NonEmptyList
defining the slice to look for- returns
the last index at which the elements of this
NonEmptyList
starting at that index match the elements ofNonEmptyList
that
, or-1
of no such subsequence exists.
-
final
def
lastIndexOfSlice[U >: T](that: Every[U]): Int
Finds the last index where this
NonEmptyList
contains a givenEvery
as a slice.Finds the last index where this
NonEmptyList
contains a givenEvery
as a slice.- that
the
Every
defining the slice to look for- returns
the last index at which the elements of this
NonEmptyList
starting at that index match the elements ofEvery
that
, or-1
of no such subsequence exists.
-
final
def
lastIndexOfSlice[U >: T](that: GenSeq[U], end: Int): Int
Finds the last index before or at a given end index where this
NonEmptyList
contains a givenGenSeq
as a slice.Finds the last index before or at a given end index where this
NonEmptyList
contains a givenGenSeq
as a slice.- that
the
GenSeq
defining the slice to look for- end
the end index
- returns
the last index
>=
end
at which the elements of thisNonEmptyList
starting at that index match the elements ofGenSeq
that
, or-1
of no such subsequence exists.
-
final
def
lastIndexOfSlice[U >: T](that: GenSeq[U]): Int
Finds the last index where this
NonEmptyList
contains a givenGenSeq
as a slice.Finds the last index where this
NonEmptyList
contains a givenGenSeq
as a slice.- that
the
GenSeq
defining the slice to look for- returns
the last index at which the elements of this
NonEmptyList
starting at that index match the elements ofGenSeq
that
, or-1
of no such subsequence exists.
-
final
def
lastIndexWhere(p: (T) ⇒ 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.
- p
the predicate used to test elements.
- end
the end index
- returns
the index
>=
end
of the last element of thisNonEmptyList
that satisfies the predicatep
, or-1
, if none exists.
-
final
def
lastIndexWhere(p: (T) ⇒ Boolean): Int
Finds index of last element satisfying some predicate.
Finds index of last element satisfying some predicate.
- p
the predicate used to test elements.
- returns
the index of the last element of this
NonEmptyList
that satisfies the predicatep
, or-1
, if none exists.
-
final
def
lastOption: Option[T]
Returns the last element of this
NonEmptyList
, wrapped in aSome
.Returns the last element of this
NonEmptyList
, wrapped in aSome
.- returns
the last element, wrapped in a
Some
.
-
final
def
length: Int
The length of this
NonEmptyList
.The length of this
NonEmptyList
.Note:
length
andsize
yield the same result, which will be>
= 1.- returns
the number of elements in this
NonEmptyList
.
-
final
def
lengthCompare(len: Int): Int
Compares the length of this
NonEmptyList
to a test value.Compares the length of this
NonEmptyList
to a test value.- len
the test value that gets compared with the length.
- returns
a value
x
wherex < 0 if this.length < len x == 0 if this.length == len x > 0 if this.length > len
-
final
def
map[U](f: (T) ⇒ U): NonEmptyList[U]
Builds a new
NonEmptyList
by applying a function to all elements of thisNonEmptyList
.Builds a new
NonEmptyList
by applying a function to all elements of thisNonEmptyList
.- U
the element type of the returned
NonEmptyList
.- f
the function to apply to each element.
- returns
a new
NonEmptyList
resulting from applying the given functionf
to each element of thisNonEmptyList
and collecting the results.
-
final
def
max[U >: T](implicit cmp: Ordering[U]): T
Finds the largest element.
Finds the largest element.
- returns
the largest element of this
NonEmptyList
.
-
final
def
maxBy[U](f: (T) ⇒ U)(implicit cmp: Ordering[U]): T
Finds the largest result after applying the given function to every element.
Finds the largest result after applying the given function to every element.
- returns
the largest result of applying the given function to every element of this
NonEmptyList
.
-
final
def
min[U >: T](implicit cmp: Ordering[U]): T
Finds the smallest element.
Finds the smallest element.
- returns
the smallest element of this
NonEmptyList
.
-
final
def
minBy[U](f: (T) ⇒ U)(implicit cmp: Ordering[U]): T
Finds the smallest result after applying the given function to every element.
Finds the smallest result after applying the given function to every element.
- returns
the smallest result of applying the given function to every element of this
NonEmptyList
.
-
final
def
mkString(start: String, sep: String, end: String): String
Displays all elements of this
NonEmptyList
in a string using start, end, and separator strings.Displays all elements of this
NonEmptyList
in a string using start, end, and separator strings.- start
the starting string.
- sep
the separator string.
- end
the ending string.
- returns
a string representation of this
NonEmptyList
. The resulting string begins with the stringstart
and ends with the stringend
. Inside, In the resulting string, the result of invokingtoString
on all elements of thisNonEmptyList
are separated by the stringsep
.
-
final
def
mkString(sep: String): String
Displays all elements of this
NonEmptyList
in a string using a separator string.Displays all elements of this
NonEmptyList
in a string using a separator string.- sep
the separator string
- returns
a string representation of this
NonEmptyList
. In the resulting string, the result of invokingtoString
on all elements of thisNonEmptyList
are separated by the stringsep
.
-
final
def
mkString: String
Displays all elements of this
NonEmptyList
in a string.Displays all elements of this
NonEmptyList
in a string.- returns
a string representation of this
NonEmptyList
. In the resulting string, the result of invokingtoString
on all elements of thisNonEmptyList
follow each other without any separator string.
-
final
def
nonEmpty: Boolean
Returns
true
to indicate thisNonEmptyList
, like allNonEmptyList
s, is non-empty.Returns
true
to indicate thisNonEmptyList
, like allNonEmptyList
s, is non-empty.- returns
true
-
final
def
padTo[U >: T](len: Int, elem: U): NonEmptyList[U]
A copy of this
NonEmptyList
with an element value appended until a given target length is reached.A copy of this
NonEmptyList
with an element value appended until a given target length is reached.- len
the target length
- elem
he padding value
- returns
a new
NonEmptyList
consisting of all elements of thisNonEmptyList
followed by the minimal number of occurrences ofelem
so that the resultingNonEmptyList
has a length of at leastlen
.
-
final
def
patch[U >: T](from: Int, that: NonEmptyList[U], replaced: Int): NonEmptyList[U]
Produces a new
NonEmptyList
where a slice of elements in thisNonEmptyList
is replaced by anotherNonEmptyList
Produces a new
NonEmptyList
where a slice of elements in thisNonEmptyList
is replaced by anotherNonEmptyList
- from
the index of the first replaced element
- that
the
NonEmptyList
whose elements should replace a slice in thisNonEmptyList
- replaced
the number of elements to drop in the original
NonEmptyList
-
final
def
permutations: Iterator[NonEmptyList[T]]
Iterates over distinct permutations.
Iterates over distinct permutations.
Here's an example:
NonEmptyList('a', 'b', 'b').permutations.toList = List(NonEmptyList(a, b, b), NonEmptyList(b, a, b), NonEmptyList(b, b, a))
- returns
an iterator that traverses the distinct permutations of this
NonEmptyList
.
-
final
def
prefixLength(p: (T) ⇒ 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.
- p
the predicate used to test elements.
- returns
the length of the longest prefix of this
NonEmptyList
such that every element of the segment satisfies the predicatep
.
-
final
def
product[U >: T](implicit num: Numeric[U]): U
The result of multiplying all the elements of this
NonEmptyList
.The result of multiplying all the elements of this
NonEmptyList
.This method can be invoked for any
NonEmptyList[T]
for which an implicitNumeric[T]
exists.- returns
the product of all elements
-
final
def
reduce[U >: T](op: (U, U) ⇒ U): U
Reduces the elements of this
NonEmptyList
using the specified associative binary operator.Reduces the elements of this
NonEmptyList
using the specified associative binary operator.The order in which operations are performed on elements is unspecified and may be nondeterministic.
- U
a type parameter for the binary operator, a supertype of T.
- op
a binary operator that must be associative.
- returns
the result of applying reduce operator
op
between all the elements of thisNonEmptyList
.
-
final
def
reduceLeft[U >: T](op: (U, T) ⇒ U): U
Applies a binary operator to all elements of this
NonEmptyList
, going left to right.Applies a binary operator to all elements of this
NonEmptyList
, going left to right.- U
the result type of the binary operator.
- op
the binary operator.
- returns
the result of inserting
op
between consecutive elements of thisNonEmptyList
, going left to right:op(...op(op(x_1, x_2), x_3), ..., x_n)
where x1, ..., xn are the elements of thisNonEmptyList
.
-
final
def
reduceLeftOption[U >: T](op: (U, T) ⇒ U): Option[U]
Applies a binary operator to all elements of this
NonEmptyList
, going left to right, returning the result in aSome
.Applies a binary operator to all elements of this
NonEmptyList
, going left to right, returning the result in aSome
.- U
the result type of the binary operator.
- op
the binary operator.
- returns
a
Some
containing the result ofreduceLeft(op)
- final def reduceOption[U >: T](op: (U, U) ⇒ U): Option[U]
-
final
def
reduceRight[U >: T](op: (T, U) ⇒ U): U
Applies a binary operator to all elements of this
NonEmptyList
, going right to left.Applies a binary operator to all elements of this
NonEmptyList
, going right to left.- U
the result of the binary operator
- op
the binary operator
- returns
the result of inserting
op
between consecutive elements of thisNonEmptyList
, going right to left:op(x_1, op(x_2, ... op(x_{n-1}, x_n)...))
where x1, ..., xn are the elements of thisNonEmptyList
.
-
final
def
reduceRightOption[U >: T](op: (T, U) ⇒ U): Option[U]
Applies a binary operator to all elements of this
NonEmptyList
, going right to left, returning the result in aSome
.Applies a binary operator to all elements of this
NonEmptyList
, going right to left, returning the result in aSome
.- U
the result of the binary operator
- op
the binary operator
- returns
a
Some
containing the result ofreduceRight(op)
-
final
def
reverse: NonEmptyList[T]
Returns new
NonEmptyList
with elements in reverse order.Returns new
NonEmptyList
with elements in reverse order.- returns
a new
NonEmptyList
with all elements of thisNonEmptyList
in reversed order.
-
final
def
reverseIterator: Iterator[T]
An iterator yielding elements in reverse order.
An iterator yielding elements in reverse order.
Note:
nonEmptyList.reverseIterator
is the same asnonEmptyList.reverse.iterator
, but might be more efficient.- returns
an iterator yielding the elements of this
NonEmptyList
in reversed order
-
final
def
reverseMap[U](f: (T) ⇒ U): NonEmptyList[U]
Builds a new
NonEmptyList
by applying a function to all elements of thisNonEmptyList
and collecting the results in reverse order.Builds a new
NonEmptyList
by applying a function to all elements of thisNonEmptyList
and collecting the results in reverse order.Note:
nonEmptyList.reverseMap(f)
is the same asnonEmptyList.reverse.map(f)
, but might be more efficient.- U
the element type of the returned
NonEmptyList
.- f
the function to apply to each element.
- returns
a new
NonEmptyList
resulting from applying the given functionf
to each element of thisNonEmptyList
and collecting the results in reverse order.
-
final
def
sameElements[U >: T](that: NonEmptyList[U]): Boolean
Checks if the given
NonEmptyList
contains the same elements in the same order as thisNonEmptyList
.Checks if the given
NonEmptyList
contains the same elements in the same order as thisNonEmptyList
.- that
the
NonEmptyList
with which to compare- returns
true
, if both this and the givenNonEmptyList
contain the same elements in the same order,false
otherwise.
-
final
def
sameElements[U >: T](that: Every[U]): Boolean
Checks if the given
Every
contains the same elements in the same order as thisNonEmptyList
.Checks if the given
Every
contains the same elements in the same order as thisNonEmptyList
.- that
the
Every
with which to compare- returns
true
, if both this and the givenEvery
contain the same elements in the same order,false
otherwise.
-
final
def
sameElements[U >: T](that: GenIterable[U]): Boolean
Checks if the given
GenIterable
contains the same elements in the same order as thisNonEmptyList
.Checks if the given
GenIterable
contains the same elements in the same order as thisNonEmptyList
.- that
the
GenIterable
with which to compare- returns
true
, if both thisNonEmptyList
and the givenGenIterable
contain the same elements in the same order,false
otherwise.
-
final
def
scan[U >: T](z: U)(op: (U, U) ⇒ U): NonEmptyList[U]
Computes a prefix scan of the elements of this
NonEmptyList
.Computes a prefix scan of the elements of this
NonEmptyList
.Note: The neutral element z may be applied more than once.
Here are some examples:
NonEmptyList(1, 2, 3).scan(0)(_ + _) == NonEmptyList(0, 1, 3, 6) NonEmptyList(1, 2, 3).scan("z")(_ + _.toString) == NonEmptyList("z", "z1", "z12", "z123")
- U
a type parameter for the binary operator, a supertype of T, and the type of the resulting
NonEmptyList
.- z
a neutral element for the scan operation; may be added to the result an arbitrary number of times, and must not change the result (e.g.,
Nil
for list concatenation, 0 for addition, or 1 for multiplication.)- op
a binary operator that must be associative
- returns
a new
NonEmptyList
containing the prefix scan of the elements in thisNonEmptyList
-
final
def
scanLeft[B](z: B)(op: (B, T) ⇒ B): NonEmptyList[B]
Produces a
NonEmptyList
containing cumulative results of applying the operator going left to right.Produces a
NonEmptyList
containing cumulative results of applying the operator going left to right.Here are some examples:
NonEmptyList(1, 2, 3).scanLeft(0)(_ + _) == NonEmptyList(0, 1, 3, 6) NonEmptyList(1, 2, 3).scanLeft("z")(_ + _) == NonEmptyList("z", "z1", "z12", "z123")
- B
the result type of the binary operator and type of the resulting
NonEmptyList
- z
the start value.
- op
the binary operator.
- returns
a new
NonEmptyList
containing the intermediate results of insertingop
between consecutive elements of thisNonEmptyList
, going left to right, with the start value,z
, on the left.
-
final
def
scanRight[B](z: B)(op: (T, B) ⇒ B): NonEmptyList[B]
Produces a
NonEmptyList
containing cumulative results of applying the operator going right to left.Produces a
NonEmptyList
containing cumulative results of applying the operator going right to left.Here are some examples:
NonEmptyList(1, 2, 3).scanRight(0)(_ + _) == NonEmptyList(6, 5, 3, 0) NonEmptyList(1, 2, 3).scanRight("z")(_ + _) == NonEmptyList("123z", "23z", "3z", "z")
- B
the result of the binary operator and type of the resulting
NonEmptyList
- z
the start value
- op
the binary operator
- returns
a new
NonEmptyList
containing the intermediate results of insertingop
between consecutive elements of thisNonEmptyList
, going right to left, with the start value,z
, on the right.
-
final
def
segmentLength(p: (T) ⇒ Boolean, from: Int): Int
Computes length of longest segment whose elements all satisfy some predicate.
Computes length of longest segment whose elements all satisfy some predicate.
- p
the predicate used to test elements.
- from
the index where the search starts.
-
final
def
size: Int
The size of this
NonEmptyList
.The size of this
NonEmptyList
.Note:
length
andsize
yield the same result, which will be>
= 1.- returns
the number of elements in this
NonEmptyList
.
-
final
def
sliding(size: Int, step: Int): Iterator[NonEmptyList[T]]
Groups elements in fixed size blocks by passing a “sliding window” over them (as opposed to partitioning them, as is done in grouped.), moving the sliding window by a given
step
each time.Groups elements in fixed size blocks by passing a “sliding window” over them (as opposed to partitioning them, as is done in grouped.), moving the sliding window by a given
step
each time.- size
the number of elements per group
- step
the distance between the first elements of successive groups
- returns
an iterator producing
NonEmptyList
s of sizesize
, except the last and the only element will be truncated if there are fewer elements thansize
.
-
final
def
sliding(size: Int): Iterator[NonEmptyList[T]]
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.)
- size
the number of elements per group
- returns
an iterator producing
NonEmptyList
s of sizesize
, except the last and the only element will be truncated if there are fewer elements thansize
.
-
final
def
sortBy[U](f: (T) ⇒ U)(implicit ord: Ordering[U]): NonEmptyList[T]
Sorts this
NonEmptyList
according to theOrdering
of the result of applying the given function to every element.Sorts this
NonEmptyList
according to theOrdering
of the result of applying the given function to every element.- U
the target type of the transformation
f
, and the type where theOrdering
ord
is defined.- f
the transformation function mapping elements to some other domain
U
.- ord
the ordering assumed on domain
U
.- returns
a
NonEmptyList
consisting of the elements of thisNonEmptyList
sorted according to theOrdering
wherex < y if ord.lt(f(x), f(y))
.
-
final
def
sortWith(lt: (T, T) ⇒ Boolean): NonEmptyList[T]
Sorts this
NonEmptyList
according to a comparison function.Sorts this
NonEmptyList
according to a comparison function.The sort is stable. That is, elements that are equal (as determined by
lt
) appear in the same order in the sortedNonEmptyList
as in the original.- returns
a
NonEmptyList
consisting of the elements of thisNonEmptyList
sorted according to the comparison functionlt
.
-
final
def
sorted[U >: T](implicit ord: Ordering[U]): NonEmptyList[U]
Sorts this
NonEmptyList
according to anOrdering
.Sorts this
NonEmptyList
according to anOrdering
.The sort is stable. That is, elements that are equal (as determined by
lt
) appear in the same order in the sortedNonEmptyList
as in the original.- ord
the
Ordering
to be used to compare elements.- returns
a
NonEmptyList
consisting of the elements of thisNonEmptyList
sorted according to the comparison functionlt
.
-
final
def
startsWith[B](that: NonEmptyList[B], offset: Int): Boolean
Indicates whether this
NonEmptyList
starts with the givenNonEmptyList
at the given index.Indicates whether this
NonEmptyList
starts with the givenNonEmptyList
at the given index.- that
the
NonEmptyList
slice to look for in thisNonEmptyList
- offset
the index at which this
NonEmptyList
is searched.- returns
true
if thisNonEmptyList
hasthat
as a slice at the indexoffset
,false
otherwise.
-
final
def
startsWith[B](that: Every[B], offset: Int): Boolean
Indicates whether this
NonEmptyList
starts with the givenEvery
at the given index.Indicates whether this
NonEmptyList
starts with the givenEvery
at the given index.- that
the
Every
slice to look for in thisNonEmptyList
- offset
the index at which this
NonEmptyList
is searched.- returns
true
if thisNonEmptyList
hasthat
as a slice at the indexoffset
,false
otherwise.
-
final
def
startsWith[B](that: NonEmptyList[B]): Boolean
Indicates whether this
NonEmptyList
starts with the givenNonEmptyList
.Indicates whether this
NonEmptyList
starts with the givenNonEmptyList
.- that
the
NonEmptyList
to test- returns
true
if this collection hasthat
as a prefix,false
otherwise.
-
final
def
startsWith[B](that: Every[B]): Boolean
Indicates whether this
NonEmptyList
starts with the givenEvery
.Indicates whether this
NonEmptyList
starts with the givenEvery
.- that
the
Every
to test- returns
true
if this collection hasthat
as a prefix,false
otherwise.
-
final
def
startsWith[B](that: GenSeq[B], offset: Int): Boolean
Indicates whether this
NonEmptyList
starts with the givenGenSeq
at the given index.Indicates whether this
NonEmptyList
starts with the givenGenSeq
at the given index.- that
the
GenSeq
slice to look for in thisNonEmptyList
- offset
the index at which this
NonEmptyList
is searched.- returns
true
if thisNonEmptyList
hasthat
as a slice at the indexoffset
,false
otherwise.
-
final
def
startsWith[B](that: GenSeq[B]): Boolean
Indicates whether this
NonEmptyList
starts with the givenGenSeq
.Indicates whether this
NonEmptyList
starts with the givenGenSeq
.- that
the
GenSeq
slice to look for in thisNonEmptyList
- returns
true
if thisNonEmptyList
hasthat
as a prefix,false
otherwise.
-
def
stringPrefix: String
Returns
"NonEmptyList"
, the prefix of this object'stoString
representation.Returns
"NonEmptyList"
, the prefix of this object'stoString
representation.- returns
the string
"NonEmptyList"
-
final
def
sum[U >: T](implicit num: Numeric[U]): U
The result of summing all the elements of this
NonEmptyList
.The result of summing all the elements of this
NonEmptyList
.This method can be invoked for any
NonEmptyList[T]
for which an implicitNumeric[T]
exists.- returns
the sum of all elements
-
final
def
to[Col[_]](implicit cbf: CanBuildFrom[Nothing, T, Col[T]]): Col[T]
Converts this
NonEmptyList
into a collection of typeCol
by copying all elements.Converts this
NonEmptyList
into a collection of typeCol
by copying all elements.- Col
the collection type to build.
- returns
a new collection containing all elements of this
NonEmptyList
.
-
final
def
toArray[U >: T](implicit classTag: ClassTag[U]): Array[U]
Converts this
NonEmptyList
to an array.Converts this
NonEmptyList
to an array.- returns
an array containing all elements of this
NonEmptyList
. AClassTag
must be available for the element type of thisNonEmptyList
.
-
final
def
toBuffer[U >: T]: Buffer[U]
Converts this
NonEmptyList
to a mutable buffer.Converts this
NonEmptyList
to a mutable buffer.- returns
a buffer containing all elements of this
NonEmptyList
.
-
final
def
toIndexedSeq: IndexedSeq[T]
Converts this
NonEmptyList
to an immutableIndexedSeq
.Converts this
NonEmptyList
to an immutableIndexedSeq
.- returns
an immutable
IndexedSeq
containing all elements of thisNonEmptyList
.
-
final
def
toIterable: Iterable[T]
Converts this
NonEmptyList
to an iterable collection.Converts this
NonEmptyList
to an iterable collection.- returns
an
Iterable
containing all elements of thisNonEmptyList
.
-
final
def
toIterator: Iterator[T]
Returns an
Iterator
over the elements in thisNonEmptyList
.Returns an
Iterator
over the elements in thisNonEmptyList
.- returns
an
Iterator
containing all elements of thisNonEmptyList
.
- val toList: List[T]
-
final
def
toMap[K, V](implicit ev: <:<[T, (K, V)]): Map[K, V]
Converts this
NonEmptyList
to a map.Converts this
NonEmptyList
to a map.This method is unavailable unless the elements are members of
Tuple2
, each((K, V))
becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys.- returns
a map of type
immutable.Map[K, V]
containing all key/value pairs of type(K, V)
of thisNonEmptyList
.
-
final
def
toSeq: Seq[T]
Converts this
NonEmptyList
to an immutableIndexedSeq
.Converts this
NonEmptyList
to an immutableIndexedSeq
.- returns
an immutable
IndexedSeq
containing all elements of thisNonEmptyList
.
-
final
def
toSet[U >: T]: Set[U]
Converts this
NonEmptyList
to a set.Converts this
NonEmptyList
to a set.- returns
a set containing all elements of this
NonEmptyList
.
-
final
def
toStream: Stream[T]
Converts this
NonEmptyList
to a stream.Converts this
NonEmptyList
to a stream.- returns
a stream containing all elements of this
NonEmptyList
.
-
def
toString(): String
Returns a string representation of this
NonEmptyList
.Returns a string representation of this
NonEmptyList
.- returns
the string
"NonEmptyList"
followed by the result of invokingtoString
on thisNonEmptyList
's elements, surrounded by parentheses.
- Definition Classes
- NonEmptyList → Any
-
final
def
toTraversable: Traversable[T]
Converts this
NonEmptyList
to an unspecified Traversable.Converts this
NonEmptyList
to an unspecified Traversable.- returns
a
Traversable
containing all elements of thisNonEmptyList
.
-
final
def
toVector: Vector[T]
Converts this
NonEmptyList
to aVector
.Converts this
NonEmptyList
to aVector
.- returns
a
Vector
containing all elements of thisNonEmptyList
.
- final def transpose[U](implicit ev: <:<[T, NonEmptyList[U]]): NonEmptyList[NonEmptyList[U]]
-
final
def
union[U >: T](that: GenSeq[U])(implicit cbf: CanBuildFrom[List[T], U, List[U]]): NonEmptyList[U]
Produces a new
NonEmptyList
that contains all elements of thisNonEmptyList
and also all elements of a givenGenSeq
.Produces a new
NonEmptyList
that contains all elements of thisNonEmptyList
and also all elements of a givenGenSeq
.nonEmptyListX
union
ys
is equivalent tononEmptyListX
++
ys
.Another way to express this is that
nonEmptyListX
union
ys
computes the order-presevring multi-set union ofnonEmptyListX
andys
. Thisunion
method is hence a counter-part ofdiff
andintersect
that also work on multi-sets.- that
the
GenSeq
to add.- returns
a new
NonEmptyList
that contains all elements of thisNonEmptyList
followed by all elements ofthat
GenSeq
.
-
final
def
union[U >: T](that: NonEmptyList[U]): NonEmptyList[U]
Produces a new
NonEmptyList
that contains all elements of thisNonEmptyList
and also all elements of a givenNonEmptyList
.Produces a new
NonEmptyList
that contains all elements of thisNonEmptyList
and also all elements of a givenNonEmptyList
.nonEmptyListX
union
nonEmptyListY
is equivalent tononEmptyListX
++
nonEmptyListY
.Another way to express this is that
nonEmptyListX
union
nonEmptyListY
computes the order-presevring multi-set union ofnonEmptyListX
andnonEmptyListY
. Thisunion
method is hence a counter-part ofdiff
andintersect
that also work on multi-sets.- that
the
NonEmptyList
to add.- returns
a new
NonEmptyList
that contains all elements of thisNonEmptyList
followed by all elements ofthat
.
-
final
def
union[U >: T](that: Every[U]): NonEmptyList[U]
Produces a new
NonEmptyList
that contains all elements of thisNonEmptyList
and also all elements of a givenEvery
.Produces a new
NonEmptyList
that contains all elements of thisNonEmptyList
and also all elements of a givenEvery
.nonEmptyListX
union
everyY
is equivalent tononEmptyListX
++
everyY
.Another way to express this is that
nonEmptyListX
union
everyY
computes the order-presevring multi-set union ofnonEmptyListX
andeveryY
. Thisunion
method is hence a counter-part ofdiff
andintersect
that also work on multi-sets.- that
the
Every
to add.- returns
a new
NonEmptyList
that contains all elements of thisNonEmptyList
followed by all elements ofthat
Every
.
-
final
def
unzip[L, R](implicit asPair: (T) ⇒ (L, R)): (NonEmptyList[L], NonEmptyList[R])
Converts this
NonEmptyList
of pairs into twoNonEmptyList
s of the first and second half of each pair.Converts this
NonEmptyList
of pairs into twoNonEmptyList
s of the first and second half of each pair.- L
the type of the first half of the element pairs
- R
the type of the second half of the element pairs
- asPair
an implicit conversion that asserts that the element type of this
NonEmptyList
is a pair.- returns
a pair of
NonEmptyList
s, containing the first and second half, respectively, of each element pair of thisNonEmptyList
.
-
final
def
unzip3[L, M, R](implicit asTriple: (T) ⇒ (L, M, R)): (NonEmptyList[L], NonEmptyList[M], NonEmptyList[R])
Converts this
NonEmptyList
of triples into threeNonEmptyList
s of the first, second, and and third element of each triple.Converts this
NonEmptyList
of triples into threeNonEmptyList
s of the first, second, and and third element of each triple.- L
the type of the first member of the element triples
- R
the type of the third member of the element triples
- asTriple
an implicit conversion that asserts that the element type of this
NonEmptyList
is a triple.- returns
a triple of
NonEmptyList
s, containing the first, second, and third member, respectively, of each element triple of thisNonEmptyList
.
-
final
def
updated[U >: T](idx: Int, elem: U): NonEmptyList[U]
A copy of this
NonEmptyList
with one single replaced element.A copy of this
NonEmptyList
with one single replaced element.- idx
the position of the replacement
- elem
the replacing element
- returns
a copy of this
NonEmptyList
with the element at positionidx
replaced byelem
.
- Exceptions thrown
IndexOutOfBoundsException
if the passed index is greater than or equal to the length of thisNonEmptyList
-
final
def
zipAll[O, U >: T](other: Iterable[O], thisElem: U, otherElem: O): NonEmptyList[(U, O)]
Returns a
NonEmptyList
formed from thisNonEmptyList
and an iterable collection by combining corresponding elements in pairs.Returns a
NonEmptyList
formed from thisNonEmptyList
and an iterable collection by combining corresponding elements in pairs. If one of the two collections is shorter than the other, placeholder elements will be used to extend the shorter collection to the length of the longer.- other
the
Iterable
providing the second half of each result pair- thisElem
the element to be used to fill up the result if this
NonEmptyList
is shorter thanthat
Iterable
.- returns
a new
NonEmptyList
containing pairs consisting of corresponding elements of thisNonEmptyList
andthat
. The length of the returned collection is the maximum of the lengths of thisNonEmptyList
andthat
. If thisNonEmptyList
is shorter thanthat
,thisElem
values are used to pad the result. Ifthat
is shorter than thisNonEmptyList
,thatElem
values are used to pad the result.
-
final
def
zipWithIndex: NonEmptyList[(T, Int)]
Zips this
NonEmptyList
with its indices.Zips this
NonEmptyList
with its indices.- returns
A new
NonEmptyList
containing pairs consisting of all elements of thisNonEmptyList
paired with their index. Indices start at 0.