TraversableEqualityConstraints

Provides three implicit methods that loosen the equality constraint defined by TypeCheckedTripleEquals or ConversionCheckedTripleEquals for Scala Traversables to one that more closely matches Scala's approach to Traversable equality.

Scala's approach to Traversable equality is that if the objects being compared are ether both Seqs, both Sets, or both Maps, the elements are compared to determine equality. This means you could compare an immutable Vector and a mutable ListBuffer for equality, for instance, and get true so long as the two Seqs contained the same elements in the same order. Here's an example:

scala> import scala.collection.mutable.ListBuffer
import scala.collection.mutable.ListBuffer
scala> Vector(1, 2) == ListBuffer(1, 2)
res0: Boolean = true

Such a comparison would not, however, compile if you used === under either TypeCheckedTripleEquals or ConversionCheckedTripleEquals, because Vector and ListBuffer are not in a subtype/supertype relationship, nor does an implicit conversion by default exist between them:

scala> import org.scalactic._
import org.scalactic._
scala> import TypeCheckedTripleEquals._
import TypeCheckedTripleEquals._
scala> Vector(1, 2) === ListBuffer(1, 2)
<console>:16: error: types scala.collection.immutable.Vector[Int] and
  scala.collection.mutable.ListBuffer[Int] do not adhere to the equality constraint selected for
  the === and !== operators; the missing implicit parameter is of type
  org.scalactic.EqualityConstraint[scala.collection.immutable.Vector[Int],
  scala.collection.mutable.ListBuffer[Int]]
              Vector(1, 2) === ListBuffer(1, 2)
                           ^

If you mix or import the implicit conversion provided by TraversableEqualityConstraint, however, the comparison will be allowed:

scala> import TraversableEqualityConstraints._
import TraversableEqualityConstraints._
scala> Vector(1, 2) === ListBuffer(1, 2)
res2: Boolean = true

The equality constraints provided by this trait require that left and right sides are both subclasses of either scala.collection.GenSeq, scala.collection.GenSet, or scala.collection.GenMap, and that an EqualityConstraint can be found for the element types for Seq and Set, or the key and value types for Maps. In the example above, both the Vector and ListBuffer are subclasses of scala.collection.GenSeq, and the regular TypeCheckedTripleEquals provides equality constraints for the element types, both of which are Int. By contrast, this trait would not allow a Vector[Int] to be compared against a ListBuffer[java.util.Date], because no equality constraint will exist between the element types Int and Date:

scala> import java.util.Date
import java.util.Date
scala> Vector(1, 2) === ListBuffer(new Date, new Date)
<console>:20: error: types scala.collection.immutable.Vector[Int] and
  scala.collection.mutable.ListBuffer[java.util.Date] do not adhere to the equality constraint selected for
  the === and !== operators; the missing implicit parameter is of type
  org.scalactic.EqualityConstraint[scala.collection.immutable.Vector[Int],
  scala.collection.mutable.ListBuffer[java.util.Date]]
              Vector(1, 2) === ListBuffer(new Date, new Date)
                           ^

This trait simply mixes together SeqEqualityConstraints, SetEqualityConstraints, and MapEqualityConstraints.

Source: TraversableEqualityConstraints.scala

Linear Supertypes

MapEqualityConstraints, SetEqualityConstraints, SeqEqualityConstraints, AnyRef, Any

Known Subclasses

TraversableEqualityConstraints

Value Members

final def !=(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def !=(arg0: Any): Boolean

Definition Classes
Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def ==(arg0: Any): Boolean

Definition Classes
Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws()
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws()
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
implicit def mapEqualityConstraint[KA, VA, CA[ka, kb] <: GenMap[ka, kb], KB, VB, CB[kb, vb] <: GenMap[kb, vb]](implicit equalityOfA: Equality[CA[KA, VA]], evKey: Constraint[KA, KB], evValue: Constraint[VA, VB]): Constraint[CA[KA, VA], CB[KB, VB]]

Provides an equality constraint that allows two subtypes of scala.collection.GenMaps to be compared for equality with === so long as an EqualityConstraint is available for both key types and both value types.
Provides an equality constraint that allows two subtypes of scala.collection.GenMaps to be compared for equality with === so long as an EqualityConstraint is available for both key types and both value types.

Definition Classes
MapEqualityConstraints
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
implicit def seqEqualityConstraint[EA, CA[ea] <: GenSeq[ea], EB, CB[eb] <: GenSeq[eb]](implicit equalityOfA: Equality[CA[EA]], ev: Constraint[EA, EB]): Constraint[CA[EA], CB[EB]]

Provides an equality constraint that allows two subtypes of scala.collection.GenSeqs to be compared for equality with === so long as an EqualityConstraint is available for the element types.
Provides an equality constraint that allows two subtypes of scala.collection.GenSeqs to be compared for equality with === so long as an EqualityConstraint is available for the element types.

Definition Classes
SeqEqualityConstraints
implicit def setEqualityConstraint[EA, CA[ea] <: GenSet[ea], EB, CB[eb] <: GenSet[eb]](implicit equalityOfA: Equality[CA[EA]], ev: Constraint[EA, EB]): Constraint[CA[EA], CB[EB]]

Provides an equality constraint that allows two subtypes of scala.collection.GenSets to be compared for equality with === so long as an EqualityConstraint is available for the element types.
Provides an equality constraint that allows two subtypes of scala.collection.GenSets to be compared for equality with === so long as an EqualityConstraint is available for the element types.

Definition Classes
SetEqualityConstraints
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws()
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws()
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws()

trait TraversableEqualityConstraints extends SeqEqualityConstraints with SetEqualityConstraints with MapEqualityConstraints

Value Members

final def !=(arg0: AnyRef): Boolean

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: AnyRef): Boolean

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def clone(): AnyRef

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

implicit def mapEqualityConstraint[KA, VA, CA[ka, kb] <: GenMap[ka, kb], KB, VB, CB[kb, vb] <: GenMap[kb, vb]](implicit equalityOfA: Equality[CA[KA, VA]], evKey: Constraint[KA, KB], evValue: Constraint[VA, VB]): Constraint[CA[KA, VA], CB[KB, VB]]

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

implicit def seqEqualityConstraint[EA, CA[ea] <: GenSeq[ea], EB, CB[eb] <: GenSeq[eb]](implicit equalityOfA: Equality[CA[EA]], ev: Constraint[EA, EB]): Constraint[CA[EA], CB[EB]]

implicit def setEqualityConstraint[EA, CA[ea] <: GenSet[ea], EB, CB[eb] <: GenSet[eb]](implicit equalityOfA: Equality[CA[EA]], ev: Constraint[EA, EB]): Constraint[CA[EA], CB[EB]]

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from MapEqualityConstraints

Inherited from SetEqualityConstraints

Inherited from SeqEqualityConstraints

Inherited from AnyRef

Inherited from Any

Ungrouped