Trait scala.collection.BuildFrom
Companion object BuildFrom
trait BuildFrom[-From, -A, +C] extends Any
Abstract Value Members
abstract def fromSpecific(from: From)(it: IterableOnce[A]): C
abstract def getClass(): Class[_ <: AnyRef]
Returns the runtime class representation of the object.
- returns
a class object corresponding to the runtime type of the receiver.
- Definition Classes
- Any
abstract def newBuilder(from: From): Builder[A, C]
Get a Builder for the collection. For non-strict collection types this will use an intermediate buffer. Building collections with fromSpecific
is preferred because it can be lazy for lazy collections.
Concrete Value Members
final def !=(arg0: Any): Boolean
Test two objects for inequality.
- returns
true
if !(this == that), false otherwise.
- Definition Classes
- Any
final def ##(): Int
Equivalent to x.hashCode
except for boxed numeric types and null
. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null
returns a hashcode where null.hashCode
throws a NullPointerException
.
- returns
a hash value consistent with ==
- Definition Classes
- Any
def +(other: String): String
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toany2stringadd[BuildFrom[From, A, C]] performed by method any2stringadd in scala.Predef.
- Definition Classes
- any2stringadd
def ->[B](y: B): (BuildFrom[From, A, C], B)
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toArrowAssoc[BuildFrom[From, A, C]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @inline()
final def ==(arg0: Any): Boolean
Test two objects for equality. The expression x == that
is equivalent to if (x eq null) that eq null else x.equals(that)
.
- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- Any
final def asInstanceOf[T0]: 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.
- returns
the receiver object.
- Definition Classes
- Any
- Exceptions thrown
ClassCastException
if the receiver object is not an instance of the erasure of typeT0
.
def ensuring(cond: (BuildFrom[From, A, C]) => Boolean, msg: => Any): BuildFrom[From, A, C]
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toEnsuring[BuildFrom[From, A, C]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: (BuildFrom[From, A, C]) => Boolean): BuildFrom[From, A, C]
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toEnsuring[BuildFrom[From, A, C]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean, msg: => Any): BuildFrom[From, A, C]
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toEnsuring[BuildFrom[From, A, C]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def ensuring(cond: Boolean): BuildFrom[From, A, C]
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toEnsuring[BuildFrom[From, A, C]] performed by method Ensuring in scala.Predef.
- Definition Classes
- Ensuring
def equals(arg0: Any): Boolean
Compares the receiver object (this
) with the argument object (that
) for equivalence.
Any implementation of this method should be an equivalence relation:
-
It is reflexive: for any instance
x
of type Any
, x.equals(x)
should return true
.It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and only if y.equals(x)
returns true
.It is transitive: for any instances x
, y
, and z
of type Any
if x.equals(y)
returns true
and y.equals(z)
returns true
, then x.equals(z)
should return true
. If you override this method, you should verify that your implementation remains an equivalence relation. Additionally, when overriding this method it is usually necessary to override hashCode
to ensure that objects which are "equal" (o1.equals(o2)
returns true
) hash to the same scala.Int. (o1.hashCode.equals(o2.hashCode)
).
- returns
true
if the receiver object is equivalent to the argument;false
otherwise.
- Definition Classes
- Any
def formatted(fmtstr: String): String
Returns string formatted according to given format
string. Format strings are as for String.format
(@see java.lang.String.format).
- Implicit
- This member is added by an implicit conversion from BuildFrom[From, A, C] toStringFormat[BuildFrom[From, A, C]] performed by method StringFormat in scala.Predef.
- Definition Classes
- StringFormat
- Annotations
- @inline()
def hashCode(): Int
Calculate a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
. However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure to verify that the behavior is consistent with the equals
method.
- returns
the hash code value for this object.
- Definition Classes
- Any
final def isInstanceOf[T0]: Boolean
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.
- returns
true
if the receiver object is an instance of erasure of typeT0
;false
otherwise.
- Definition Classes
- Any
def toFactory(from: From): Factory[A, C]
def toString(): String
Returns a string representation of the object.
The default representation is platform dependent.
- returns
a string representation of the object.
- Definition Classes
- Any
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/collection/BuildFrom.html
Builds a collection of type
C
from elements of typeA
when a source collection of typeFrom
is available. Implicit instances ofBuildFrom
are available for all collection types.Type of source collection
Type of elements (e.g.
Int
,Boolean
, etc.)Type of collection (e.g.
List[Int]
,TreeMap[Int, String]
, etc.)