trait
SeqEqualityConstraints
extends AnyRef
Value Members
-
def
!=
(arg0: AnyRef): Boolean
-
def
!=
(arg0: Any): Boolean
-
def
##
(): Int
-
def
==
(arg0: AnyRef): Boolean
-
def
==
(arg0: Any): Boolean
-
def
asInstanceOf
[T0]
: T0
-
def
clone
(): AnyRef
-
def
eq
(arg0: AnyRef): Boolean
-
def
equals
(arg0: Any): Boolean
-
def
finalize
(): Unit
-
def
getClass
(): java.lang.Class[_]
-
def
hashCode
(): Int
-
def
isInstanceOf
[T0]
: Boolean
-
def
ne
(arg0: AnyRef): Boolean
-
def
notify
(): Unit
-
def
notifyAll
(): Unit
-
implicit def
seqEqualityConstraint
[EA, CA[_] <: scala.collection.GenSeq[_], EB, CB[_] <: scala.collection.GenSeq[_]]
(implicit equalityOfA: Equality[CA[EA]], ev: EqualityConstraint[EA, EB]): EqualityConstraint[CA[EA], CB[EB]]
-
def
synchronized
[T0]
(arg0: ⇒ T0): T0
-
def
toString
(): String
-
def
wait
(): Unit
-
def
wait
(arg0: Long, arg1: Int): Unit
-
def
wait
(arg0: Long): Unit
Inherited from AnyRef
Inherited from Any
Provides an implicit method that loosens the equality constraint defined by
TypeCheckedTripleEquals
orConversionCheckedTripleEquals
for ScalaSeq
s to one that more closely matches Scala's approach toSeq
equality.Scala's approach to
Seq
equality is that if both objects being compared areSeq
s, the elements are compared to determine equality. This means you could compare an immutableVector
and a mutableListBuffer
for equality, for instance, and get true so long as the twoSeq
s contained the same elements in the same order. Here's an example:Such a comparison would not, however, compile if you used
===
under eitherTypeCheckedTripleEquals
orConversionCheckedTripleEquals
, becauseVector
andListBuffer
are not in a subtype/supertype relationship, nor does an implicit conversion by default exist between them:If you mix or import the implicit conversion provided by
SeqEqualityConstraint
, however, the comparison will be allowed:The equality constraint provided by this trait requires that both left and right sides are subclasses of
scala.collection.GenSeq
and that anEqualityConstraint
can be found for the element types. In the example above, both theVector
andListBuffer
are subclasses ofscala.collection.GenSeq
, and the regularTypeCheckedTripleEquals
provides equality constraints for the element types, both of which areInt
. By contrast, this trait would not allow aVector[Int]
to be compared against aListBuffer[java.util.Date]
, because no equality constraint will exist between the element typesInt
andDate
: