the first element of the list
the list containing the remaining elements of this list after the first one.
The type implementing this traversable
The type implementing this traversable
A class supporting filtered operations.
Test two objects for inequality.
Test two objects for inequality.
true
if !(this == that), false otherwise.
Equivalent to x.hashCode
except for boxed numeric types.
Equivalent to x.hashCode
except for boxed numeric types.
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.
a hash value consistent with ==
[use case] Concatenates this list with the elements of a traversable collection.
Concatenates this list with the elements of a traversable collection.
the element type of the returned collection.
the traversable to append.
a new collection of type That
which contains all elements
of this list followed by all elements of that
.
Concatenates this list with the elements of a traversable collection.
Concatenates this list with the elements of a traversable collection.
the element type of the returned collection.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the traversable to append.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
which contains all elements
of this list followed by all elements of that
.
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions.
This overload exists because: for the implementation of ++: we should reuse that of ++ because many collections override it with more efficient versions. Since TraversableOnce has no '++' method, we have to implement that directly, but Traversable and down can use the overload.
[use case] Concatenates this list with the elements of a traversable collection.
Concatenates this list with the elements of a traversable collection. It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one.
the element type of the returned collection.
the traversable to append.
a new collection of type That
which contains all elements
of this list followed by all elements of that
.
Concatenates this list with the elements of a traversable collection.
Concatenates this list with the elements of a traversable collection. It differs from ++ in that the right operand determines the type of the resulting collection rather than the left one.
the element type of the returned collection.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the traversable to append.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
which contains all elements
of this list followed by all elements of that
.
[use case] Prepends an element to this list
Prepends an element to this list
the prepended element
a new collection of type That
consisting of elem
followed
by all elements of this list.
Prepends an element to this list
Prepends an element to this list
the element type of the returned list.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the prepended element
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
consisting of elem
followed
by all elements of this list.
Applies a binary operator to a start value and all elements of this list, going left to right.
Applies a binary operator to a start value and all elements of this list, going left to right.
Note: /:
is alternate syntax for foldLeft
; z /: xs
is the same as
xs foldLeft z
.
the result type of the binary operator.
the start value.
the binary operator.
the result of inserting op
between consecutive elements of this list,
going left to right with the start value z
on the left:
op(...op(op(z, x,,1,,), x,,2,,), ..., x,,n,,)
where x,,1,,, ..., x,,n,,
are the elements of this list.
A syntactic sugar for out of order folding.
A syntactic sugar for out of order folding. See fold
.
[use case] Appends an element to this list
Appends an element to this list
the appended element
a new collection of type That
consisting of
all elements of this list followed by elem
.
Appends an element to this list
Appends an element to this list
the element type of the returned list.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the appended element
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
consisting of
all elements of this list followed by elem
.
[use case] Adds an element at the beginning of this list.
Adds an element at the beginning of this list.
the element to prepend.
a list which contains x
as first element and
which continues with this list.
Adds an element at the beginning of this list.
Adds an element at the beginning of this list.
the element to prepend.
a list which contains x
as first element and
which continues with this list.
1 :: List(2, 3) = List(2, 3).::(1) = List(1, 2, 3)
[use case] Adds the elements of a given list in front of this list.
Adds the elements of a given list in front of this list.
The list elements to prepend.
a list resulting from the concatenation of the given
list prefix
and this list.
Adds the elements of a given list in front of this list.
Adds the elements of a given list in front of this list.
The list elements to prepend.
a list resulting from the concatenation of the given
list prefix
and this list.
List(1, 2) ::: List(3, 4) = List(3, 4).:::(List(1, 2)) = List(1, 2, 3, 4)
Applies a binary operator to all elements of this list and a start value, going right to left.
Applies a binary operator to all elements of this list and a start value, going right to left.
Note: :\
is alternate syntax for foldRight
; xs :\ z
is the same as
xs foldRight z
.
the result type of the binary operator.
the start value
the binary operator
the result of inserting op
between consecutive elements of this list,
going right to left with the start value z
on the right:
op(x,,1,,, op(x,,2,,, ... op(x,,n,,, z)...))
where x,,1,,, ..., x,,n,,
are the elements of this list.
Test two objects for equality.
Test two objects for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
Appends all elements of this list to a string builder.
Appends all elements of this list to a string builder.
The written text consists of the string representations (w.r.t. the method
toString
) of all elements of this list without any separator string.
the string builder to which elements are appended.
the string builder b
to which elements were appended.
Appends all elements of this list to a string builder using a separator string.
Appends all elements of this 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 list, separated by the
string sep
.
the string builder to which elements are appended.
the separator string.
the string builder b
to which elements were appended.
Appends all elements of this list to a string builder using start, end, and separator strings.
Appends all elements of this 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 list are separated by the string sep
.
the string builder to which elements are appended.
the starting string.
the separator string.
the ending string.
the string builder b
to which elements were appended.
Aggregates the results of applying an operator to subsequent elements.
Aggregates the results of applying an operator to subsequent elements.
This is a more general form of fold
and reduce
. It has similar semantics, but does
not require the result to be a supertype of the element type. It traverses the elements in
different partitions sequentially, using seqop
to update the result, and then
applies combop
to results from different partitions. The implementation of this
operation may operate on an arbitrary number of collection partitions, so combop
may be invoked arbitrary number of times.
For example, one might want to process some elements and then produce a Set
. In this
case, seqop
would process an element and append it to the list, while combop
would concatenate two lists from different partitions together. The initial value
z
would be an empty set.
pc.aggregate(Set[Int]())(_ += process(_), _ ++ _)
Another example is calculating geometric mean from a collection of doubles (one would typically require big doubles for this).
the initial value for the accumulated result of the partition - this
will typically be the neutral element for the seqop
operator (e.g.
Nil
for list concatenation or 0
for summation)
an operator used to accumulate results within a partition
an associative operator used to combine results from different partitions
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.
the result type of the transformation function.
the transformation function
a partial function with the same domain as this partial function, which maps
arguments x
to k(this(x))
.
Selects an element by its index in the list.
Selects an element by its index in the list.
Note: the execution of apply
may take time proportial to the index value.
the element of this list at index idx
, where 0
indicates the first element.
Cast the receiver object to be of type T0
.
Cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics.
Therefore the expression 1.asInstanceOf[String]
will throw a ClassCastException
at
runtime, while the expression List(1).asInstanceOf[List[String]]
will not.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the requested type.
the receiver object.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
Method called from equality methods, so that user-defined subclasses can refuse to be equal to other collections of the same kind.
The object with which this list should be compared
true
, if this list can possibly equal that
, false
otherwise. The test
takes into consideration only the run-time types of objects but ignores their elements.
Create a copy of the receiver object.
[use case] Builds a new collection by applying a partial function to all elements of this list on which the function is defined.
Builds a new collection by applying a partial function to all elements of this list on which the function is defined.
the element type of the returned collection.
the partial function which filters and maps the list.
a new collection of type That
resulting from applying the partial function
pf
to each element on which it is defined and collecting the results.
The order of the elements is preserved.
Builds a new collection by applying a partial function to all elements of this list on which the function is defined.
Builds a new collection by applying a partial function to all elements of this list on which the function is defined.
the element type of the returned collection.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the partial function which filters and maps the list.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
resulting from applying the partial function
pf
to each element on which it is defined and collecting the results.
The order of the elements is preserved.
Finds the first element of the list for which the given partial function is defined, and applies the partial function to it.
Finds the first element of the list for which the given partial function is defined, and applies the partial function to it.
the partial function
an option value containing pf applied to the first
value for which it is defined, or None
if none exists.
Seq("a", 1, 5L).collectFirst({ case x: Int => x*10 }) = Some(10)
Iterates over combinations.
Iterates over combinations.
An Iterator which traverses the possible n-element combinations of this list.
"abbbc".combinations(2) = Iterator(ab, ac, bb, bc)
The factory companion object that builds instances of class List.
The factory companion object that builds instances of class List.
(or its Iterable
superclass where class List is not a Seq
.)
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.
the type to which function g
can be applied
a function A => T1
a new function f
such that f(x) == apply(g(x))
Tests whether this list contains a given value as an element.
Tests whether this list contains a given value as an element.
the element to test.
true
if this list has an element that is
is equal (wrt ==
) to elem
, false
otherwise.
Tests whether this list contains a given sequence as a slice.
Tests whether this list contains a given sequence as a slice.
the sequence to test
true
if this list contains a slice with the same elements
as that
, otherwise false
.
[use case] Copies elements of this list to an array.
Copies elements of this list to an array.
Fills the given array xs
with at most len
elements of
this list, starting at position start
.
Copying will stop once either the end of the current list is reached,
or the end of the array is reached, or len
elements have been copied.
the array to fill.
the starting index.
the maximal number of elements to copy.
Copies elements of this list to an array.
Copies elements of this list to an array.
Fills the given array xs
with at most len
elements of
this list, starting at position start
.
Copying will stop once either the end of the current list is reached,
or the end of the array is reached, or len
elements have been copied.
the type of the elements of the array.
the array to fill.
the starting index.
the maximal number of elements to copy.
[use case] Copies values of this list to an array.
Copies values of this list to an array.
Fills the given array xs
with values of this list.
Copying will stop once either the end of the current list is reached,
or the end of the array is reached.
the array to fill.
Copies values of this list to an array.
Copies values of this list to an array.
Fills the given array xs
with values of this list.
Copying will stop once either the end of the current list is reached,
or the end of the array is reached.
the type of the elements of the array.
the array to fill.
[use case] Copies values of this list to an array.
Copies values of this list to an array.
Fills the given array xs
with values of this list, beginning at index start
.
Copying will stop once either the end of the current list is reached,
or the end of the array is reached.
the array to fill.
the starting index.
Copies values of this list to an array.
Copies values of this list to an array.
Fills the given array xs
with values of this list, beginning at index start
.
Copying will stop once either the end of the current list is reached,
or the end of the array is reached.
the type of the elements of the array.
the array to fill.
the starting index.
Copies all elements of this list to a buffer.
Copies all elements of this list to a buffer.
The buffer to which elements are copied.
Tests whether every element of this list relates to the corresponding element of another sequence by satisfying a test predicate.
Tests whether every element of this list relates to the corresponding element of another sequence by satisfying a test predicate.
the type of the elements of that
the other sequence
the test predicate, which relates elements from both sequences
true
if both sequences have the same length and
p(x, y)
is true
for all corresponding elements x
of this list
and y
of that
, otherwise false
.
Counts the number of elements in the list which satisfy a predicate.
Counts the number of elements in the list which satisfy a predicate.
the predicate used to test elements.
the number of elements satisfying the predicate p
.
[use case] Computes the multiset difference between this list and another sequence.
Computes the multiset difference between this list and another sequence.
the sequence of elements to remove
a new collection of type That
which contains all elements of this 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.
Computes the multiset difference between this list and another sequence.
Computes the multiset difference between this list and another sequence.
the element type of the returned list.
the sequence of elements to remove
a new collection of type That
which contains all elements of this 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.
Builds a new list from this list without any duplicate elements.
Builds a new list from this list without any duplicate elements.
A new list which contains the first occurrence of every element of this list.
Selects all elements except first n ones.
Selects all elements except first n ones.
the number of elements to drop from this list.
a list consisting of all elements of this list except the first n
ones, or else the
empty list, if this list has less than n
elements.
Selects all elements except last n ones.
Selects all elements except last n ones.
The number of elements to take
a list consisting of all elements of this list except the last n
ones, or else the
empty list, if this list has less than n
elements.
Drops longest prefix of elements that satisfy a predicate.
Drops longest prefix of elements that satisfy a predicate.
The predicate used to test elements.
the longest suffix of this list whose first element
does not satisfy the predicate p
.
Tests whether this list ends with the given sequence.
Tests whether this list ends with the given sequence.
the sequence to test
true
if this list has that
as a suffix, false
otherwise.
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
Tests whether the argument (arg0
) is a reference to the receiver object (this
).
The eq
method implements an equivalence relation on
non-null instances of AnyRef
, and has three additional properties:
x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.null.eq(null)
returns true
. When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
true
if the argument is a reference to the receiver object; false
otherwise.
The equals method for arbitrary sequences.
Tests whether a predicate holds for some of the elements of this list.
Tests whether a predicate holds for some of the elements of this list.
the predicate used to test elements.
true
if the given predicate p
holds for some of the
elements of this list, otherwise false
.
Selects all elements of this list which satisfy a predicate.
Selects all elements of this list which satisfy a predicate.
the predicate used to test elements.
a new list consisting of all elements of this list that satisfy the given
predicate p
. The order of the elements is preserved.
Selects all elements of this list which do not satisfy a predicate.
Selects all elements of this list which do not satisfy a predicate.
the predicate used to test elements.
a new list consisting of all elements of this list that do not satisfy the given
predicate p
. The order of the elements is preserved.
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.
Finds the first element of the list satisfying a predicate, if any.
Finds the first element of the list satisfying a predicate, if any.
the predicate used to test elements.
an option value containing the first element in the list
that satisfies p
, or None
if none exists.
[use case] Builds a new collection by applying a function to all elements of this list and concatenating the results.
Builds a new collection by applying a function to all elements of this list and concatenating the results.
the element type of the returned collection.
the function to apply to each element.
a new collection of type That
resulting from applying the given collection-valued function
f
to each element of this list and concatenating the results.
Builds a new collection by applying a function to all elements of this list and concatenating the results.
Builds a new collection by applying a function to all elements of this list and concatenating the results.
the element type of the returned collection.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the function to apply to each element.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
resulting from applying the given collection-valued function
f
to each element of this list and concatenating the results.
[use case] Converts this list of traversable collections into a list in which all element collections are concatenated.
Converts this list of traversable collections into a list in which all element collections are concatenated.
the type of the elements of each traversable collection.
a new list resulting from concatenating all element lists.
Converts this list of traversable collections into a list in which all element collections are concatenated.
Converts this list of traversable collections into a list in which all element collections are concatenated.
the type of the elements of each traversable collection.
an implicit conversion which asserts that the element
type of this list is a Traversable
.
a new list resulting from concatenating all element lists.
Folds the elements of this sequence using the specified associative binary operator.
Folds the elements of this sequence using the specified associative binary operator. The order in which the elements are reduced is unspecified and may be nondeterministic.
Note this method has a different signature than the foldLeft
and foldRight
methods of the trait Traversable
.
The result of folding may only be a supertype of this parallel collection's
type parameter T
.
a neutral element for the fold operation, it may be added to the result
an arbitrary number of times, not changing the result (e.g. Nil
for list concatenation,
0 for addition, or 1 for multiplication)
a binary operator that must be associative
the result of applying fold operator op
between all the elements and z
Applies a binary operator to a start value and all elements of this list, going left to right.
Applies a binary operator to a start value and all elements of this list, going left to right.
the result type of the binary operator.
the start value.
the result of inserting op
between consecutive elements of this list,
going left to right with the start value z
on the left:
op(...op(z, x,,1,,), x,,2,,, ..., x,,n,,)
where x,,1,,, ..., x,,n,,
are the elements of this list.
Applies a binary operator to all elements of this list and a start value, going right to left.
Applies a binary operator to all elements of this list and a start value, going right to left.
the result type of the binary operator.
the start value.
the result of inserting op
between consecutive elements of this list,
going right to left with the start value z
on the right:
op(x,,1,,, op(x,,2,,, ... op(x,,n,,, z)...))
where x,,1,,, ..., x,,n,,
are the elements of this list.
Tests whether a predicate holds for all elements of this list.
Tests whether a predicate holds for all elements of this list.
the predicate used to test elements.
true
if the given predicate p
holds for all elements
of this list, otherwise false
.
[use case] Applies a function f
to all elements of this list.
Applies a function f
to all elements of this list.
the function that is applied for its side-effect to every element.
The result of function f
is discarded.
Applies a function f
to all elements of this list.
Applies a function f
to all elements of this list.
Note: this method underlies the implementation of most other bulk operations. Subclasses should re-implement this method if a more efficient implementation exists.
the function that is applied for its side-effect to every element.
The result of function f
is discarded.
The generic builder that builds instances of List at arbitrary element types.
The generic builder that builds instances of List at arbitrary element types.
A representation that corresponds to the dynamic class of the receiver object.
A representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
Partitions this list into a map of lists according to some discriminator function.
Partitions this list into a map of lists according to some discriminator function.
Note: this method is not re-implemented by views. This means when applied to a view it will always force the view and return a new list.
the type of keys returned by the discriminator function.
the discriminator function.
A map from keys to lists such that the following invariant holds:
(xs partition f)(k) = xs filter (x => f(x) == k)
That is, every key k
is bound to a list of those elements x
for which f(x)
equals k
.
Partitions elements in fixed size lists.
Partitions elements in fixed size lists.
the number of elements per group
An iterator producing lists of size size
, except the
last will be truncated if the elements don't divide evenly.
Iterator#grouped
Tests whether this list is known to have a finite size.
Tests whether this 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.
Note: many collection methods will not work on collections of infinite sizes.
true
if this collection is known to have finite size, false
otherwise.
Hashcodes for List produce a value from the hashcodes of all the elements of the list.
Hashcodes for List produce a value from the hashcodes of all the elements of the list.
the hash code value for this object.
Selects the first element of this list.
Selects the first element of this list.
the first element of this list.
Optionally selects the first element.
Optionally selects the first element.
the first element of this list if it is nonempty, None
if it is empty.
[use case] Finds index of first occurrence of some value in this list after or at some start index.
Finds index of first occurrence of some value in this list after or at some start index.
the element value to search for.
the start index
the index >= from
of the first element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
Finds index of first occurrence of some value in this list after or at some start index.
Finds index of first occurrence of some value in this list after or at some start index.
the type of the element elem
.
the element value to search for.
the start index
the index >= from
of the first element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
[use case] Finds index of first occurrence of some value in this list.
Finds index of first occurrence of some value in this list.
the element value to search for.
the index of the first element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
Finds index of first occurrence of some value in this list.
Finds index of first occurrence of some value in this list.
the type of the element elem
.
the element value to search for.
the index of the first element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
Finds first index after or at a start index where this list contains a given sequence as a slice.
Finds first index after or at a start index where this list contains a given sequence as a slice.
the sequence to test
the start index
the first index >= from
such that the elements of this list starting at this index
match the elements of sequence that
, or -1
of no such subsequence exists.
Finds first index where this list contains a given sequence as a slice.
Finds first index where this list contains a given sequence as a slice.
the sequence to test
the first index such that the elements of this list starting at this index
match the elements of sequence that
, or -1
of no such subsequence exists.
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.
the predicate used to test elements.
the start index
the index >= from
of the first element of this list that satisfies the predicate p
,
or -1
, if none exists.
Finds index of first element satisfying some predicate.
Finds index of first element satisfying some predicate.
the predicate used to test elements.
the index of the first element of this list that satisfies the predicate p
,
or -1
, if none exists.
Produces the range of all indices of this sequence.
Produces the range of all indices of this sequence.
a Range
value from 0
to one less than the length of this list.
Selects all elements except the last.
Selects all elements except the last.
a list consisting of all elements of this list except the last one.
Iterates over the inits of this list.
Iterates over the inits of this list. The first value will be this
list and the final one will be an empty list, with the intervening
values the results of successive applications of init
.
an iterator over all the inits of this list
List(1,2,3).inits = Iterator(List(1,2,3), List(1,2), List(1), Nil)
[use case] Computes the multiset intersection between this list and another sequence.
Computes the multiset intersection between this list and another sequence.
the sequence of elements to intersect with.
a new collection of type That
which contains all elements of this 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.
Computes the multiset intersection between this list and another sequence.
Computes the multiset intersection between this list and another sequence.
the element type of the returned list.
the sequence of elements to intersect with.
a new collection of type That
which contains all elements of this 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.
Tests whether this list contains given index.
Tests whether this list contains given index.
The implementations of methods apply
and isDefinedAt
turn a Seq[A]
into
a PartialFunction[Int, A]
.
true
if this list contains an element at position idx
, false
otherwise.
Tests whether the list is empty.
Tests whether the list is empty.
true
if the list contains no elements, false
otherwise.
Test whether the dynamic type of the receiver object is T0
.
Test whether the dynamic type of the receiver object is T0
.
Note that the result of the test is modulo Scala's erasure semantics.
Therefore the expression 1.isInstanceOf[String]
will return false
, while the
expression List(1).isInstanceOf[List[String]]
will return true
.
In the latter example, because the type argument is erased as part of compilation it is
not possible to check whether the contents of the list are of the specified type.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
Tests whether this list can be repeatedly traversed.
Tests whether this list can be repeatedly traversed.
true
Creates a new iterator over all elements contained in this iterable object.
Creates a new iterator over all elements contained in this iterable object.
the new iterator
Selects the last element.
Selects the last element.
The last element of this list.
[use case] Finds index of last occurrence of some value in this list before or at a given end index.
Finds index of last occurrence of some value in this list before or at a given end index.
the element value to search for.
the end index.
the index <= end
of the last element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
Finds index of last occurrence of some value in this list before or at a given end index.
Finds index of last occurrence of some value in this list before or at a given end index.
the type of the element elem
.
the element value to search for.
the end index.
the index <= end
of the last element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
[use case] Finds index of last occurrence of some value in this list.
Finds index of last occurrence of some value in this list.
the element value to search for.
the index of the last element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
Finds index of last occurrence of some value in this list.
Finds index of last occurrence of some value in this list.
the type of the element elem
.
the element value to search for.
the index of the last element of this list that is equal (wrt ==
)
to elem
, or -1
, if none exists.
Finds last index before or at a given end index where this list contains a given sequence as a slice.
Finds last index before or at a given end index where this list contains a given sequence as a slice.
the sequence to test
the end index
the last index <= end
such that the elements of this list starting at this index
match the elements of sequence that
, or -1
of no such subsequence exists.
Finds last index where this list contains a given sequence as a slice.
Finds last index where this list contains a given sequence as a slice.
the sequence to test
the last index such that the elements of this list starting a this index
match the elements of sequence that
, or -1
of no such subsequence exists.
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.
the predicate used to test elements.
the index <= end
of the last element of this list that satisfies the predicate p
,
or -1
, if none exists.
Finds index of last element satisfying some predicate.
Finds index of last element satisfying some predicate.
the predicate used to test elements.
the index of the last element of this list that satisfies the predicate p
,
or -1
, if none exists.
Optionally selects the last element.
Optionally selects the last element.
the last element of this list$ if it is nonempty, None
if it is empty.
The length of the list.
The length of the list.
Note: the execution of length
may take time proportial to the length of the sequence.
the number of elements in this list.
Compares the length of this list to a test value.
Compares the length of this list to a test value.
the test value that gets compared with the length.
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 overwritten
if computing length
is cheap.
Turns this partial function into an plain function returning an Option
result.
Turns this partial function into an plain function returning an Option
result.
a function that takes an argument x
to Some(this(x))
if this
is defined for x
, and to None
otherwise.
Function.unlift
[use case] Builds a new collection by applying a function to all elements of this list.
Builds a new collection by applying a function to all elements of this list.
the element type of the returned collection.
the function to apply to each element.
a new collection of type That
resulting from applying the given function
f
to each element of this list and collecting the results.
Builds a new collection by applying a function to all elements of this list.
Builds a new collection by applying a function to all elements of this list.
the element type of the returned collection.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the function to apply to each element.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
resulting from applying the given function
f
to each element of this list and collecting the results.
[use case] Builds a new list by applying a function to all elements of this list.
Builds a new list by applying a function to all elements of this list.
Like xs map f
, but returns xs
unchanged if function
f
maps all elements to themselves (wrt eq).
the function to apply to each element.
a list resulting from applying the given function
f
to each element of this list and collecting the results.
Builds a new list by applying a function to all elements of this list.
Builds a new list by applying a function to all elements of this list.
Like xs map f
, but returns xs
unchanged if function
f
maps all elements to themselves (wrt eq).
the element type of the returned collection.
the function to apply to each element.
a list resulting from applying the given function
f
to each element of this list and collecting the results.
[use case] Finds the largest element.
Finds the largest element.
the largest element of this list with respect to the ordering cmp
.
Finds the largest element.
Finds the largest element.
The type over which the ordering is defined.
An ordering to be used for comparing elements.
the largest element of this list with respect to the ordering cmp
.
[use case] Finds the smallest element.
Finds the smallest element.
the smallest element of this list with respect to the ordering cmp
.
Finds the smallest element.
Finds the smallest element.
The type over which the ordering is defined.
An ordering to be used for comparing elements.
the smallest element of this list with respect to the ordering cmp
.
Displays all elements of this list in a string.
Displays all elements of this list in a string.
a string representation of this list. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this list follow each other without any
separator string.
Displays all elements of this list in a string using a separator string.
Displays all elements of this list in a string using a separator string.
the separator string.
a string representation of this list. In the resulting string
the string representations (w.r.t. the method toString
)
of all elements of this list are separated by the string sep
.
List(1, 2, 3).mkString("|") = "1|2|3"
Displays all elements of this list in a string using start, end, and separator strings.
Displays all elements of this list in a string using start, end, and separator strings.
the starting string.
the separator string.
the ending string.
a string representation of this 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 list are separated by
the string sep
.
List(1, 2, 3).mkString("(", "; ", ")") = "(1; 2; 3)"
Equivalent to !(this eq that)
.
Equivalent to !(this eq that)
.
true
if the argument is not a reference to the receiver object; false
otherwise.
The builder that builds instances of type List[A]
The builder that builds instances of type List[A]
Tests whether the list is not empty.
Tests whether the list is not empty.
true
if the list contains at least one element, false
otherwise.
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.
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.
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.
the argument type of the fallback function
the result type of the fallback function
the fallback function
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.
[use case] Appends an element value to this list until a given target length is reached.
Appends an element value to this list until a given target length is reached.
the target length
the padding value
a new collection of type That
consisting of
all elements of this list followed by the minimal number of occurrences of elem
so
that the resulting collection has a length of at least len
.
Appends an element value to this list until a given target length is reached.
Appends an element value to this list until a given target length is reached.
the element type of the returned list.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the target length
the padding value
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
consisting of
all elements of this list followed by the minimal number of occurrences of elem
so
that the resulting collection has a length of at least len
.
Returns a parallel implementation of this collection.
Returns a parallel implementation of this collection.
For most collection types, this method creates a new parallel collection by copying
all the elements. For these collection, par
takes linear time. Mutable collections
in this category do not produce a mutable parallel collection that has the same
underlying dataset, so changes in one collection will not be reflected in the other one.
Specific collections (e.g. ParArray
or mutable.ParHashMap
) override this default
behaviour by creating a parallel collection which shares the same underlying dataset.
For these collections, par
takes constant or sublinear time.
All parallel collections return a reference to themselves.
a parallel implementation of this collection
The default par
implementation uses the combiner provided by this method
to create a new parallel collection.
The default par
implementation uses the combiner provided by this method
to create a new parallel collection.
a combiner for the parallel collection of type ParRepr
Partitions this list in two lists according to a predicate.
Partitions this list in two lists according to a predicate.
the predicate on which to partition.
a pair of lists: the first list consists of all elements that
satisfy the predicate p
and the second list consists of all elements
that don't. The relative order of the elements in the resulting lists
is the same as in the original list.
[use case] Produces a new list where a slice of elements in this list is replaced by another sequence.
Produces a new list where a slice of elements in this list is replaced by another sequence.
the index of the first replaced element
the number of elements to drop in the original list
a new list consisting of all elements of this list
except that replaced
elements starting from from
are replaced
by patch
.
Produces a new list where a slice of elements in this list is replaced by another sequence.
Produces a new list where a slice of elements in this list is replaced by another sequence.
the element type of the returned list.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the index of the first replaced element
the replacement sequence
the number of elements to drop in the original list
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new list consisting of all elements of this list
except that replaced
elements starting from from
are replaced
by patch
.
Iterates over distinct permutations.
Iterates over distinct permutations.
An Iterator which traverses the distinct permutations of this list.
"abb".permutations = Iterator(abb, bab, bba)
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.
the predicate used to test elements.
the length of the longest prefix of this list
such that every element of the segment satisfies the predicate p
.
[use case] Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the product of all elements of this list with respect to the *
operator in num
.
Multiplies up the elements of this collection.
Multiplies up the elements of this collection.
the result type of the *
operator.
an implicit parameter defining a set of numeric operations
which includes the *
operator to be used in forming the product.
the product of all elements of this list with respect to the *
operator in num
.
The size of this product.
The nth element of this product, 0-based.
An iterator over all the elements of this product.
An iterator over all the elements of this product.
in the default implementation, an Iterator[Any]
A string used in the toString
methods of derived classes.
Reduces the elements of this sequence using the specified associative binary operator.
Reduces the elements of this sequence using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
Note this method has a different signature than the reduceLeft
and reduceRight
methods of the trait Traversable
.
The result of reducing may only be a supertype of this parallel collection's
type parameter T
.
A binary operator that must be associative.
The result of applying reduce operator op
between all the elements if the collection is nonempty.
Optionally applies a binary operator to all elements of this list, going left to right.
Optionally applies a binary operator to all elements of this list, going left to right.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceLeft(op)
is this list is nonempty,
None
otherwise.
Optionally reduces the elements of this sequence using the specified associative binary operator.
Optionally reduces the elements of this sequence using the specified associative binary operator.
The order in which operations are performed on elements is unspecified and may be nondeterministic.
Note this method has a different signature than the reduceLeftOption
and reduceRightOption
methods of the trait Traversable
.
The result of reducing may only be a supertype of this parallel collection's
type parameter T
.
A binary operator that must be associative.
An option value containing result of applying reduce operator op
between all
the elements if the collection is nonempty, and None
otherwise.
Applies a binary operator to all elements of this list, going right to left.
Applies a binary operator to all elements of this list, going right to left.
the result type of the binary operator.
the binary operator.
the result of inserting op
between consecutive elements of this list,
going right to left:
op(x,,1,,, op(x,,2,,, ..., op(x,,n-1,,, x,,n,,)...))
where x,,1,,, ..., x,,n,,
are the elements of this list.
Optionally applies a binary operator to all elements of this list, going right to left.
Optionally applies a binary operator to all elements of this list, going right to left.
the result type of the binary operator.
the binary operator.
an option value containing the result of reduceRight(op)
is this list is nonempty,
None
otherwise.
The collection of type list underlying this TraversableLike
object.
The collection of type list underlying this TraversableLike
object.
By default this is implemented as the TraversableLike
object itself,
but this can be overridden.
Returns new list wih elements in reversed order.
An iterator yielding elements in reversed order.
An iterator yielding elements in reversed order.
Note: xs.reverseIterator
is the same as xs.reverse.iterator
but might be more efficient.
an iterator yielding the elements of this list in reversed order
[use case] Builds a new collection by applying a function to all elements of this list and collecting the results in reversed order.
Builds a new collection by applying a function to all elements of this list and collecting the results in reversed order.
the element type of the returned collection.
the function to apply to each element.
a new collection of type That
resulting from applying the given function
f
to each element of this list and collecting the results in reversed order.
Note: xs.reverseMap(f)
is the same as xs.reverse.map(f)
but might be more efficient.
Builds a new collection by applying a function to all elements of this list and collecting the results in reversed order.
Builds a new collection by applying a function to all elements of this list and collecting the results in reversed order.
Note: xs.reverseMap(f)
is the same as xs.reverse.map(f)
but might be more efficient.
the element type of the returned collection.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the function to apply to each element.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
resulting from applying the given function
f
to each element of this list and collecting the results in reversed order.
[use case] Adds the elements of a given list in reverse order in front of this list.
Adds the elements of a given list in reverse order in front of this list.
xs reverse_::: ys
is equivalent to
xs.reverse ::: ys
but is more efficient.
the prefix to reverse and then prepend
the concatenation of the reversed prefix and the current list.
Adds the elements of a given list in reverse order in front of this list.
Adds the elements of a given list in reverse order in front of this list.
xs reverse_::: ys
is equivalent to
xs.reverse ::: ys
but is more efficient.
the prefix to reverse and then prepend
the concatenation of the reversed prefix and the current list.
[use case] Checks if the other iterable collection contains the same elements in the same order as this list.
Checks if the other iterable collection contains the same elements in the same order as this list.
the collection to compare with.
true
, if both collections contain the same elements in the same order, false
otherwise.
Checks if the other iterable collection contains the same elements in the same order as this list.
Checks if the other iterable collection contains the same elements in the same order as this list.
the type of the elements of collection that
.
the collection to compare with.
true
, if both collections contain the same elements in the same order, false
otherwise.
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.
element type of the resulting collection
type of the resulting collection
neutral element for the operator op
the associative operator for the scan
combiner factory which provides a combiner
a new list containing the prefix scan of the elements in this list
Produces a collection containing cummulative results of applying the operator going left to right.
Produces a collection containing cummulative results of applying the operator going left to right.
the type of the elements in the resulting collection
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
collection with intermediate results
Produces a collection containing cummulative results of applying the operator going right to left.
Produces a collection containing cummulative results of applying the operator going right to left. The head of the collection is the last cummulative result.
Example:
List(1, 2, 3, 4).scanRight(0)(_ + _) == List(10, 9, 7, 4, 0)
the type of the elements in the resulting collection
the actual type of the resulting collection
the initial value
the binary operator applied to the intermediate result and the element
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
collection with intermediate results
"This scanRight definition has changed in 2.9.\n" + "The previous behavior can be reproduced with scanRight.reverse."
Computes length of longest segment whose elements all satisfy some predicate.
Computes length of longest segment whose elements all satisfy some predicate.
the predicate used to test elements.
the index where the search starts.
the length of the longest segment of this list starting from index from
such that every element of the segment satisfies the predicate p
.
A version of this collection with all of the operations implemented sequentially (i.
A version of this collection with all of the operations implemented sequentially (i.e. in a single-threaded manner).
This method returns a reference to this collection. In parallel collections, it is redefined to return a sequential implementation of this collection. In both cases, it has O(1) complexity.
a sequential view of the collection.
The size of this list, equivalent to length
.
The size of this list, equivalent to length
.
the number of elements in this list.
Selects an interval of elements.
Selects an interval of elements. The returned collection is made up
of all elements x
which satisfy the invariant:
from <= indexOf(x) < until
the lowest index to include from this list.
the highest index to EXCLUDE from this list.
a list containing the elements greater than or equal to
index from
extending up to (but not including) index until
of this list.
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 number of elements per group
An iterator producing lists of size size
, except the
last and the only element will be truncated if there are
fewer elements than size.
Iterator#sliding
Sorts this List according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
Sorts this List according to the Ordering which results from transforming an implicitly given Ordering with a transformation function.
the target type of the transformation f
, and the type where
the ordering ord
is defined.
the transformation function mapping elements
to some other domain B
.
the ordering assumed on domain B
.
a list consisting of the elements of this list
sorted according to the ordering where x < y
if
ord.lt(f(x), f(y))
.
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]] words.sortBy(x => (x.length, x.head)) res0: Array[String] = Array(The, dog, fox, the, lazy, over, brown, quick, jumped)
scala.math.Ordering
Sorts this list according to a comparison function.
Sorts this list according to a comparison function.
The sort is stable. That is, elements that are equal wrt lt
appear in the
same order in the sorted sequence as in the original.
the comparison function which tests whether its first argument precedes its second argument in the desired ordering.
a list consisting of the elements of this list
sorted according to the comparison function lt
.
List("Steve", "Tom", "John", "Bob").sortWith(_.compareTo(_) < 0) = List("Bob", "John", "Steve", "Tom")
Sorts this list according to an Ordering.
Sorts this list according to an Ordering.
The sort is stable. That is, elements that are equal wrt lt
appear in the
same order in the sorted sequence as in the original.
the ordering to be used to compare elements.
a list consisting of the elements of this list
sorted according to the ordering ord
.
scala.math.Ordering
Splits this list into a prefix/suffix pair according to a predicate.
Splits this 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.
the test predicate
a pair consisting of the longest prefix of this list whose
elements all satisfy p
, and the rest of this list.
Splits this list into two at a given position.
Splits this list into two at a given position.
Note: c splitAt n
is equivalent to (but possibly more efficient than)
(c take n, c drop n)
.
the position at which to split.
a pair of lists consisting of the first n
elements of this list, and the other elements.
Tests whether this list contains the given sequence at a given index.
Tests whether this list contains the given sequence at a given index.
If the both the receiver object, this
and
the argument, that
are infinite sequences
this method may not terminate.
the sequence to test
the index where the sequence is searched.
true
if the sequence that
is contained in this list at index offset
,
otherwise false
.
Tests whether this list starts with the given sequence.
Tests whether this list starts with the given sequence.
the sequence to test
true
if this collection has that
as a prefix, false
otherwise.
Defines the prefix of this object's toString
representation.
Defines the prefix of this object's toString
representation.
a string representation which starts the result of toString
applied to this list. By default the string prefix is the
simple name of the collection class list.
[use case] Sums up the elements of this collection.
Sums up the elements of this collection.
the sum of all elements of this list with respect to the +
operator in num
.
Sums up the elements of this collection.
Sums up the elements of this collection.
the result type of the +
operator.
an implicit parameter defining a set of numeric operations
which includes the +
operator to be used in forming the sum.
the sum of all elements of this list with respect to the +
operator in num
.
Selects all elements except the first.
Selects all elements except the first.
a list consisting of all elements of this list except the first one.
Iterates over the tails of this list.
Iterates over the tails of this list. The first value will be this
list and the final one will be an empty list, with the intervening
values the results of successive applications of tail
.
an iterator over all the tails of this list
List(1,2,3).tails = Iterator(List(1,2,3), List(2,3), List(3), Nil)
Selects first n elements.
Selects first n elements.
Tt number of elements to take from this list.
a list consisting only of the first n
elements of this list,
or else the whole list, if it has less than n
elements.
Selects last n elements.
Selects last n elements.
the number of elements to take
a list consisting only of the last n
elements of this list, or else the
whole list, if it has less than n
elements.
Takes longest prefix of elements that satisfy a predicate.
Takes longest prefix of elements that satisfy a predicate.
The predicate used to test elements.
the longest prefix of this list whose elements all satisfy
the predicate p
.
The underlying collection seen as an instance of List
.
The underlying collection seen as an instance of List
.
By default this is implemented as the current collection object itself,
but this can be overridden.
[use case] Converts this list to an array.
Converts this list to an array.
an array containing all elements of this list.
Converts this list to an array.
Converts this list to an array.
the type of the elements of the array. A ClassManifest
for
this type must be available.
an array containing all elements of this list.
Converts this list to a mutable buffer.
Converts this list to a mutable buffer.
a buffer containing all elements of this list.
A conversion from collections of type Repr
to List
objects.
A conversion from collections of type Repr
to List
objects.
By default this is implemented as just a cast, but this can be overridden.
Converts this list to an indexed sequence.
Converts this list to an indexed sequence.
an indexed sequence containing all elements of this list.
Converts this list to an iterable collection.
Converts this list to an iterable collection. Note that
the choice of target Iterable
is lazy in this default implementation
as this TraversableOnce
may be lazy and unevaluated (i.e. it may
be an iterator which is only traversable once).
an Iterable
containing all elements of this list.
Returns an Iterator over the elements in this list.
Returns an Iterator over the elements in this list. Will return the same Iterator if this instance is already an Iterator.
an Iterator containing all elements of this list.
Converts this list to a list.
Converts this list to a list.
a list containing all elements of this list.
[use case] Converts this list to a map.
Converts this list to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.
a map containing all elements of this list.
Converts this list to a map.
Converts this list to a map. This method is unavailable unless the elements are members of Tuple2, each ((T, U)) becoming a key-value pair in the map. Duplicate keys will be overwritten by later keys: if this is an unordered collection, which key is in the resulting map is undefined.
a map containing all elements of this list.
Converts this list to a sequence.
Converts this list to a sequence.
Overridden for efficiency.
a sequence containing all elements of this list.
Converts this list to a set.
Converts this list to a set.
a set containing all elements of this list.
Converts this list to a stream.
Converts this list to a stream.
a stream containing all elements of this list.
Converts this list to a string.
Converts this list to a string.
a string representation of this collection. By default this
string consists of the stringPrefix
of this list,
followed by all elements separated by commas and enclosed in parentheses.
Converts this list to an unspecified Traversable.
Converts this list to an unspecified Traversable. Will return the same collection if this instance is already Traversable.
a Traversable containing all elements of this list.
Transposes this list of traversable collections into a list of lists.
Transposes this list of traversable collections into a list of lists.
the type of the elements of each traversable collection.
an implicit conversion which asserts that the
element type of this list is a Traversable
.
a two-dimensional list of lists which has as nth row the nth column of this list.
[use case] Produces a new sequence which contains all elements of this list and also all elements of a given sequence.
Produces a new sequence which contains all elements of this list and also all elements of
a given sequence. xs union ys
is equivalent to xs ++ ys
.
the sequence to add.
a new collection of type That
which contains all elements of this list
followed by all elements of that
.
Produces a new sequence which contains all elements of this list and also all elements of a given sequence.
Produces a new sequence which contains all elements of this list and also all elements of
a given sequence. xs union ys
is equivalent to xs ++ ys
.
Another way to express this
is that xs union ys
computes the order-presevring multi-set union of xs
and ys
.
union
is hence a counter-part of diff
and intersect
which also work on multi-sets.
the element type of the returned list.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the sequence to add.
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new collection of type That
which contains all elements of this list
followed by all elements of that
.
Converts this list of pairs into two collections of the first and second half of each pair.
Converts this list of pairs into two collections of the first and second half of each pair.
an implicit conversion which asserts that the element type of this list is a pair.
a pair lists, containing the first, respectively second half of each element pair of this list.
Converts this list of triples into three collections of the first, second, and third element of each triple.
Converts this list of triples into three collections of the first, second, and third element of each triple.
a triple lists, containing the first, second, respectively third member of each element triple of this list.
[use case] A copy of this list with one single replaced element.
A copy of this list with one single replaced element.
the position of the replacement
the replacing element
a new list which is a copy of this list with the element at position
index replaced by
elem.
A copy of this list with one single replaced element.
A copy of this list with one single replaced element.
the element type of the returned list.
the class of the returned collection. In the standard library configuration,
That
is always List[B]
because an implicit of type CanBuildFrom[List, B, That]
is defined in object List
.
the position of the replacement
the replacing element
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type B
. This is usually the canBuildFrom
value
defined in object List
.
a new list which is a copy of this list with the element at position
index replaced by
elem.
Creates a non-strict view of a slice of this list.
Creates a non-strict view of a slice of this list.
Note: the difference between view
and slice
is that view
produces
a view of the current list, whereas slice
produces a new list.
Note: view(from, to)
is equivalent to view.slice(from, to)
the index of the first element of the view
the index of the element following the view
a non-strict view of a slice of this list, starting at index from
and extending up to (but not including) index until
.
Creates a non-strict view of this list.
Creates a non-strict view of this list.
a non-strict view of this list.
Creates a non-strict filter of this list.
Creates a non-strict filter of this list.
Note: the difference between c filter p
and c withFilter p
is that
the former creates a new collection, whereas the latter only
restricts the domain of subsequent map
, flatMap
, foreach
,
and withFilter
operations.
the predicate used to test elements.
an object of class WithFilter
, which supports
map
, flatMap
, foreach
, and withFilter
operations.
All these operations apply to those elements of this list which
satisfy the predicate p
.
[use case] Returns a list formed from this list and another iterable collection by combining corresponding elements in pairs.
Returns a list formed from this 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.
the type of the second half of the returned pairs
The iterable providing the second half of each result pair
a new collection of type That
containing pairs consisting of
corresponding elements of this list and that
. The length
of the returned collection is the minimum of the lengths of this list and that
.
Returns a list formed from this list and another iterable collection by combining corresponding elements in pairs.
Returns a list formed from this 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.
the type of the first half of the returned pairs (this is always a supertype
of the collection's element type A
).
the type of the second half of the returned pairs
the class of the returned collection. Where possible, That
is
the same class as the current collection class Repr
, but this
depends on the element type (A1, B)
being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, (A1, B), That]
.
is found.
The iterable providing the second half of each result pair
an implicit value of class CanBuildFrom
which determines the
result class That
from the current representation type Repr
and the new element type (A1, B)
.
a new collection of type That
containing pairs consisting of
corresponding elements of this list and that
. The length
of the returned collection is the minimum of the lengths of this list and that
.
[use case] Returns a list formed from this list and another iterable collection by combining corresponding elements in pairs.
Returns a list formed from this 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.
the iterable providing the second half of each result pair
the element to be used to fill up the result if this list is shorter than that
.
the element to be used to fill up the result if that
is shorter than this list.
a new collection of type That
containing pairs consisting of
corresponding elements of this list and that
. The length
of the returned collection is the maximum of the lengths of this list and that
.
If this list is shorter than that
, thisElem
values are used to pad the result.
If that
is shorter than this list, thatElem
values are used to pad the result.
Returns a list formed from this list and another iterable collection by combining corresponding elements in pairs.
Returns a list formed from this 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.
the iterable providing the second half of each result pair
the element to be used to fill up the result if this list is shorter than that
.
the element to be used to fill up the result if that
is shorter than this list.
a new collection of type That
containing pairs consisting of
corresponding elements of this list and that
. The length
of the returned collection is the maximum of the lengths of this list and that
.
If this list is shorter than that
, thisElem
values are used to pad the result.
If that
is shorter than this list, thatElem
values are used to pad the result.
[use case] Zips this list with its indices.
Zips this list with its indices.
A new collection of type That
containing pairs consisting of all elements of this
list paired with their index. Indices start at 0
.
Zips this list with its indices.
Zips this list with its indices.
the type of the first half of the returned pairs (this is always a supertype
of the collection's element type A
).
the class of the returned collection. Where possible, That
is
the same class as the current collection class Repr
, but this
depends on the element type (A1, Int)
being admissible for that class,
which means that an implicit instance of type CanBuildFrom[Repr, (A1, Int), That]
.
is found.
A new collection of type That
containing pairs consisting of all elements of this
list paired with their index. Indices start at 0
.
Computes the difference between this list and the given object
x
.
Computes the difference between this list and the given object
x
.
the object to remove from this list.
this list without occurrences of the given object
x
.
use filterNot (_ == x)
instead
Computes the difference between this list and the given list
that
.
Computes the difference between this list and the given list
that
.
the list of elements to remove from this list.
this list without the elements of the given list
that
.
use list1 filterNot (list2 contains)
instead
Like span
but with the predicate inverted.
Like span
but with the predicate inverted.
use span { x => !p(x) }
instead
use iterator' instead
Tests whether every element of this list relates to the corresponding element of another sequence by satisfying a test predicate.
Tests whether every element of this list relates to the corresponding element of another sequence by satisfying a test predicate.
the type of the elements of that
the other sequence
true
if both sequences have the same length and
p(x, y)
is true
for all corresponding elements x
of this list
and y
of that
, otherwise false
.
use corresponds
instead
Returns index of the first element satisfying a predicate, or -1
.
Returns index of the first element satisfying a predicate, or -1
.
Use indexWhere(p) instead.
Returns index of the last element satisfying a predicate, or -1.
Returns index of the last element satisfying a predicate, or -1.
use lastIndexWhere
instead
use head' instead
None
if iterable is empty.
None
if iterable is empty.
use headOption' instead
use productIterator instead
returns a projection that can be used to call non-strict filter
,
map
, and flatMap
methods that build projections
of the collection.
returns a projection that can be used to call non-strict filter
,
map
, and flatMap
methods that build projections
of the collection.
use view' instead
use filterNot' instead
use distinct' instead
use reverseIterator' instead
use sortWith' instead
A non empty list characterized by a head and a tail.
the type of the list elements.
the first element of the list
the list containing the remaining elements of this list after the first one.
1.0, 15/07/2003
2.8