Scala Library Documentation


scala/Seq.scala
]
trait
Seq[+A]
extends
PartialFunction[Int, A] with
Collection[A]Seq[A]
represents finite sequences of elements
of type A
.Method Summary  
override def

++
[B >: A](that : Iterable[B]) : Seq[B]
Appends two iterable objects.

override def

concat
[B >: A](that : Iterable[B]) : Seq[B]
Appends two iterable objects.

def

contains
(elem : Any) : Boolean
Tests if the given value
elem is a member of this
sequence. 
def

containsSlice
[B](that : Seq[B]) : Boolean
Is
that a slice in this? 
override def

drop
(n : Int) : Seq[A]
Returns this sequence without its
n first elements
If this sequence has less than n elements, the empty
sequence is returned. (nonstrict) 
override def

dropWhile
(p : (A) => Boolean) : Seq[A]
Returns the longest suffix of this sequence whose first element
does not satisfy the predicate
p . 
def

endsWith [B](that : Seq[B]) : Boolean 
def

equalsWith [B](that : Seq[B])(f : (A, B) => Boolean) : Boolean 
override def

filter
(p : (A) => Boolean) : Seq[A]
Returns all the elements of this sequence that satisfy the
predicate
p . The order of the elements is preserved. 
override def

flatMap
[B](f : (A) => Iterable[B]) : Seq[B]
Applies the given function
f to each element of
this sequence, then concatenates the results. 
def

headOption
: Option[A]
Returns as an option the first element of this list or None if list is empty.

def

indexOf [B >: A](that : Seq[B]) : Int 
def

isDefinedAt
(x : Int) : Boolean
Is this partial function defined for the index
x ? 
override def

isEmpty
: Boolean
Returns true if length == 0

def

last
: A
Returns the last element of this list.

def

lastIndexOf
[B >: A](elem : B) : Int
Returns the index of the last occurence of the specified element
in this sequence, or 1 if the sequence does not contain this element.

def

lastOption
: Option[A]
Returns as an option the last element of this list or None if list is empty.

abstract def

length
: Int
Returns the length of the sequence.

def

lengthCompare
(l : Int) : Int
Returns length  l. This method is used by matching streams against rightignoring (...,_) patterns.
Lazy sequences should override this method if length forces evaluation of the stream.

override def

map
[B](f : (A) => B) : Seq[B]
Returns the sequence resulting from applying the given function
f to each element of this sequence. 
override def

projection
: Projection[A]
returns a projection that can be used to call nonstrict
filter ,
map , and flatMap methods that build projections
of the collection. 
def

reverse
: Seq[A]
A sequence consisting of all elements of this sequence in reverse order.

def

size
: Int
should always be
length 
def

slice
(from : Int, until : Int) : Seq[A]
A subsequence of
len elements
starting at index from (nonstrict) 
def

startsWith [B](that : Seq[B]) : Boolean 
def

subseq
(from : Int, end : Int) : Seq[A]
Returns a subsequence starting from index
from
consisting of len elements. 
override def

take
(n : Int) : Seq[A]
Returns a sequence consisting only over the first
n
elements of this sequence, or else the whole sequence, if it has less
than n elements. (nonstrict) 
override def

takeWhile
(p : (A) => Boolean) : Seq[A]
Returns the longest prefix of this sequence whose elements satisfy
the predicate
p . 
override def

toArray
[B >: A] : Array[B]
Converts this sequence to a fresh Array with
length elements. 
Methods inherited from Collection  
toString, stringPrefix 
Methods inherited from Iterable  
elements (abstract), partition, foreach, forall, exists, find, findIndexOf, indexOf, foldLeft, foldRight, /:, :\, reduceLeft, reduceRight, copyToBuffer, sameElements, toList, toStream, mkString, mkString, mkString, addString, addString, copyToArray, hasDefiniteSize 
Methods inherited from PartialFunction  
orElse, andThen 
Methods inherited from Function1  
apply (abstract), compose 
Methods inherited from AnyRef  
getClass, hashCode, equals, clone, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized 
Methods inherited from Any  
==, !=, isInstanceOf, asInstanceOf 
Method Details 
abstract
def
length : Int
def
size : Int
length
override
def
isEmpty : Boolean
++
instead
def
last : A
x
?x 
..true
, iff x
is a legal sequence index.elem 
element to search for.f
to each element of this sequence.f 
function to apply to each element.f(a_{0}), ..., f(a_{n})
if this sequence is a_{0}, ..., a_{n}
.f
to each element of
this sequence, then concatenates the results.f 
the function to apply on each element.f(a_{0}) ::: ... ::: f(a_{n})
if this sequence is a_{0}, ..., a_{n}
.p
. The order of the elements is preserved.p 
the predicate used to filter the list.p
.n
elements of this sequence, or else the whole sequence, if it has less
than n
elements. (nonstrict)n 
the number of elements to taken
first elements
If this sequence has less than n
elements, the empty
sequence is returned. (nonstrict)n 
the number of elements to droplen
elements
starting at index from
(nonstrict)from 
The index of the first element of the sliceuntil 
The index of the element following the sliceIndexOutOfBoundsException 
if from < 0
or length < from + len
 Returns the longest prefix of this sequence whose elements satisfy
the predicate
p
.

Parameters
p 
the test predicate.
Returns
 the longest prefix of this sequence whose elements satisfy the predicate
p
.
 Returns the longest suffix of this sequence whose first element
does not satisfy the predicate
p
.

Parameters
p 
the test predicate.
Returns
 the longest suffix of the sequence whose first element does not satisfy the predicate
p
.
 A sequence consisting of all elements of this sequence in reverse order.
 Tests if the given value
elem
is a member of this
sequence.

Parameters
elem 
element whose membership has to be tested.
Returns
true
iff there is an element of this sequence which is equal (w.r.t. ==
) to elem
.

@deprecated
def
subseq(from : Int, end : Int) : Seq[A]
 Returns a subsequence starting from index
from
consisting of len
elements.

Deprecated
 use
slice
instead
 Converts this sequence to a fresh Array with
length
elements.

Overrides

Collection.toArray

override
def
projection : Projection[A]
 returns a projection that can be used to call nonstrict
filter
,
map
, and flatMap
methods that build projections
of the collection.

Returns
 s true if this sequence start with that sequences

See Also
 String.startsWith

Returns
 s true if this sequence end with that sequence

See Also
 String.endsWith

Returns
 s 1 if
that
not contained in this, otherwise the index where that
is contained 
See Also
 String.indexOf
 Is
that
a slice in this?
Scala Library Documentation