TripleEqualsSupport

Companion object TripleEqualsSupport

trait TripleEqualsSupport extends AnyRef

Trait that defines abstract methods used to enforce compile-time type constraints for equality comparisons, and defines === and !== operators used by matchers.

The abstract methods of this trait are selectively implemented as implicit by subclasses to enable a spectrum of type constraints for the === and !== operators. As an illustration, if in the expression, a === b, the type of a is A and b is B, the following three levels of compile-time checking can be obtained from TripleEqualsSupport subtraits:

Unchecked - A and B can be any two types. This constraint level is available from subtrait TripleEquals.

Statically-checked - A must be a subtype of B, or vice versa, or must cooperate such that the equality laws stated in the equals contract are preserved. This (intermediate) constraint level is available by using subtrait TripleEquals and installing the SuperSafe Community Edition Scala compiler plugin.

Type-checked - A must be a subtype of B, or vice versa. (Both A and B can be the same type, because a type is considered a subtype of itself.) This (strongest) constraint level is available from subtrait TypeCheckedTripleEquals.

This trait defines all methods that need to be defined implicitly by the subtraits so that if multiple subtraits are used together, the inner-most subtrait in scope can not only enable the implicits it needs by overriding or hiding those methods (currently-in-scope as regular, non-implicit methods) and making them implicit, it can also disable any implicits enabled by its sibling subtraits in enclosing scopes. For example, if your test class mixes in TypeCheckedTripleEquals, inside your test class the following methods will be implicit:

convertToCheckingEqualizer
typeCheckedConstraint
lowPriorityTypeCheckedConstraint
convertEquivalenceToAToBConstraint
convertEquivalenceToBToAConstraint

If in the body of a test you want to turn off the type checking, you can import the members of TripleEquals in the body of that test. This will not only hide non-implicit methods convertToEqualizer unconstrainedEquality of TypeCheckedTripleEquals, replacing those with implicit ones defined in TripleEquals, it will also hide the three methods made implicit in TypeCheckedTripleEquals (and listed above), replacing them by non-implicit ones.

In short, you should be able to select a primary constraint level via either a mixin or import, then change that in nested scopes however you want, again either through a mixin or import, without getting any implicit conversion ambiguity. The innermost constraint level in scope will always be in force.

Source: TripleEqualsSupport.scala

Linear Supertypes

AnyRef, Any

Known Subclasses

LowPriorityTypeCheckedConstraint, TripleEquals, TripleEquals, TypeCheckedTripleEquals, TypeCheckedTripleEquals

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Type Members

class CheckingEqualizer[L] extends AnyRef
Class used via an implicit conversion to enable two objects to be compared with === and !== with a Boolean result and an enforced type constraint between two object types.
Class used via an implicit conversion to enable two objects to be compared with === and !== with a Boolean result and an enforced type constraint between two object types. For example:
```
assert(a === b)
assert(c !== d)
```
You can also check numeric values against another with a tolerance. Here are some examples:
```
assert(a === (2.0 +- 0.1))
assert(c !== (2.0 +- 0.1))
```
class Equalizer[L] extends AnyRef
Class used via an implicit conversion to enable any two objects to be compared with === and !== with a Boolean result and no enforced type constraint between two object types.
Class used via an implicit conversion to enable any two objects to be compared with === and !== with a Boolean result and no enforced type constraint between two object types. For example:
```
assert(a === b)
assert(c !== d)
```
You can also check numeric values against another with a tolerance. Here are some examples:
```
assert(a === (2.0 +- 0.1))
assert(c !== (2.0 +- 0.1))
```

Abstract Value Members

abstract def convertEquivalenceToAToBConstraint[A, B](equivalenceOfB: Equivalence[B])(implicit ev: <:<[A, B]): CanEqual[A, B]
Provides a A CanEqual B for any two types A and B, enforcing the type constraint that A must be a subtype of B, given an explicit Equivalence[B].
Provides a A CanEqual B for any two types A and B, enforcing the type constraint that A must be a subtype of B, given an explicit Equivalence[B].
This method is used to enable the Explicitly DSL for TypeCheckedTripleEquals by requiring an explicit Equivalance[B], but taking an implicit function that provides evidence that A is a subtype of B.
The returned Constraint's areEqual method uses the implicitly passed Equivalence[B]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits LowPriorityTypeCheckedConstraint (extended by TypeCheckedTripleEquals), and overriden as non-implicit by the other subtraits in this package.
equivalenceOfB
an Equivalence[B] type class to which the Constraint.areEqual method will delegate to determine equality.
ev
evidence that A is a subype of B
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[B].
abstract def convertEquivalenceToBToAConstraint[A, B](equivalenceOfA: Equivalence[A])(implicit ev: <:<[B, A]): CanEqual[A, B]
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that B must be a subtype of A, given an explicit Equivalence[A].
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that B must be a subtype of A, given an explicit Equivalence[A].
This method is used to enable the Explicitly DSL for TypeCheckedTripleEquals by requiring an explicit Equivalance[B], but taking an implicit function that provides evidence that A is a subtype of B. For example, under TypeCheckedTripleEquals, this method (as an implicit method), would be used to compile this statement:
```
def closeEnoughTo1(num: Double): Boolean =
  (num === 1.0)(decided by forgivingEquality)
```
The returned Constraint's areEqual method uses the implicitly passed Equivalence[A]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits TypeCheckedTripleEquals) and overriden as non-implicit by the other subtraits in this package.
ev
evidence that B is a subype of A
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[A].
abstract def convertToCheckingEqualizer[T](left: T): CheckingEqualizer[T]
Converts to an CheckingEqualizer that provides === and !== operators that result in Boolean and enforce a type constraint.
Converts to an CheckingEqualizer that provides === and !== operators that result in Boolean and enforce a type constraint.
This method is overridden and made implicit by subtrait TypeCheckedTripleEquals, and overriden as non-implicit by the other subtraits in this package.
left
the object whose type to convert to CheckingEqualizer.
Exceptions thrown
NullPointerException if left is null.
abstract def convertToEqualizer[T](left: T): Equalizer[T]
Converts to an Equalizer that provides === and !== operators that result in Boolean and enforce no type constraint.
Converts to an Equalizer that provides === and !== operators that result in Boolean and enforce no type constraint.
This method is overridden and made implicit by subtrait TripleEquals and overriden as non-implicit by the other subtraits in this package.
left
the object whose type to convert to Equalizer.
Exceptions thrown
NullPointerException if left is null.
abstract def lowPriorityTypeCheckedConstraint[A, B](implicit equivalenceOfB: Equivalence[B], ev: <:<[A, B]): CanEqual[A, B]
Provides an A CanEqual B for any two types A and B, enforcing the type constraint that A must be a subtype of B, given an implicit Equivalence[B].
Provides an A CanEqual B for any two types A and B, enforcing the type constraint that A must be a subtype of B, given an implicit Equivalence[B].
The returned Constraint's areEqual method uses the implicitly passed Equivalence[A]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits LowPriorityTypeCheckedConstraint (extended by TypeCheckedTripleEquals), and overriden as non-implicit by the other subtraits in this package.
equivalenceOfB
an Equivalence[B] type class to which the Constraint.areEqual method will delegate to determine equality.
ev
evidence that A is a subype of B
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[B].
abstract def typeCheckedConstraint[A, B](implicit equivalenceOfA: Equivalence[A], ev: <:<[B, A]): CanEqual[A, B]
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that B must be a subtype of A, given an implicit Equivalence[A].
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that B must be a subtype of A, given an implicit Equivalence[A].
The returned Constraint's areEqual method uses the implicitly passed Equivalence[A]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits TypeCheckedTripleEquals) and overriden as non-implicit by the other subtraits in this package.
ev
evidence that B is a subype of A
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[A].
abstract def unconstrainedEquality[A, B](implicit equalityOfA: Equality[A]): CanEqual[A, B]
Provides an A CanEqual B instance for any two types A and B, with no type constraint enforced, given an implicit Equality[A].
Provides an A CanEqual B instance for any two types A and B, with no type constraint enforced, given an implicit Equality[A].
The returned Constraint's areEqual method uses the implicitly passed Equality[A]'s areEqual method to determine equality.
This method is overridden and made implicit by subtraits TripleEquals and overriden as non-implicit by the other subtraits in this package.
equalityOfA
an Equality[A] type class to which the Constraint.areEqual method will delegate to determine equality.
returns
an A CanEqual B instance whose areEqual method delegates to the areEqual method of the passed Equality[A].
abstract def conversionCheckedConstraint[A, B](implicit equivalenceOfA: Equivalence[A], cnv: (B) => A): CanEqual[A, B]
The conversionCheckedConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
The conversionCheckedConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that B is implicitly convertible to A, given an implicit Equivalence[A].
The returned Constraint's areEqual method uses the implicitly passed Equivalence[A]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits ConversionCheckedTripleEquals) and overriden as non-implicit by the other subtraits in this package.
equivalenceOfA
an Equivalence[A] type class to which the Constraint.areEqual method will delegate to determine equality.
cnv
an implicit conversion from B to A
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[A].
Annotations
@deprecated
Deprecated
(Since version 3.1.0) The conversionCheckedConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
abstract def convertEquivalenceToAToBConversionConstraint[A, B](equivalenceOfB: Equivalence[B])(implicit ev: (A) => B): CanEqual[A, B]
The convertEquivalenceToAToBConversionConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
The convertEquivalenceToAToBConversionConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that A is implicitly convertible to B, given an explicit Equivalence[B].
This method is used to enable the Explicitly DSL for ConversionCheckedTripleEquals by requiring an explicit Equivalance[B], but taking an implicit function that converts from A to B.
The returned Constraint's areEqual method uses the implicitly passed Equivalence[B]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits LowPriorityConversionCheckedConstraint (extended by ConversionCheckedTripleEquals), and overriden as non-implicit by the other subtraits in this package.
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[B].
Annotations
@deprecated
Deprecated
(Since version 3.1.0) The convertEquivalenceToAToBConversionConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
abstract def convertEquivalenceToBToAConversionConstraint[A, B](equivalenceOfA: Equivalence[A])(implicit ev: (B) => A): CanEqual[A, B]
The convertEquivalenceToBToAConversionConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
The convertEquivalenceToBToAConversionConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that B is implicitly convertible to A, given an explicit Equivalence[A].
This method is used to enable the Explicitly DSL for ConversionCheckedTripleEquals by requiring an explicit Equivalance[A], but taking an implicit function that converts from B to A. For example, under ConversionCheckedTripleEquals, this method (as an implicit method), would be used to compile this statement:
```
def closeEnoughTo1(num: Double): Boolean =
  (num === 1.0)(decided by forgivingEquality)
```
The returned Constraint's areEqual method uses the implicitly passed Equivalence[A]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits ConversionCheckedTripleEquals) and overriden as non-implicit by the other subtraits in this package.
equivalenceOfA
an Equivalence[A] type class to which the Constraint.areEqual method will delegate to determine equality.
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[A].
Annotations
@deprecated
Deprecated
(Since version 3.1.0) The convertEquivalenceToBToAConversionConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
abstract def lowPriorityConversionCheckedConstraint[A, B](implicit equivalenceOfB: Equivalence[B], cnv: (A) => B): CanEqual[A, B]
The lowPriorityConversionCheckedConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
The lowPriorityConversionCheckedConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.
Provides an A CanEqual B instance for any two types A and B, enforcing the type constraint that A is implicitly convertible to B, given an implicit Equivalence[B].
The returned Constraint's areEqual method uses the implicitly passed Equivalence[B]'s areEquivalent method to determine equality.
This method is overridden and made implicit by subtraits LowPriorityConversionCheckedConstraint (extended by ConversionCheckedTripleEquals), and overriden as non-implicit by the other subtraits in this package.
cnv
an implicit conversion from A to B
returns
an A CanEqual B instance whose areEqual method delegates to the areEquivalent method of the passed Equivalence[B].
Annotations
@deprecated
Deprecated
(Since version 3.1.0) The lowPriorityConversionCheckedConstraint method has been deprecated and will be removed in a future version of Scalactic. It is no longer needed now that the deprecation period of ConversionCheckedTripleEquals has expired. It will not be replaced.

Concrete Value Members

final def !=(arg0: Any): Boolean
Definition Classes
AnyRef → Any
def !==[T](right: Spread[T]): TripleEqualsInvocationOnSpread[T]
Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should !== (<pivot> +- <tolerance>)” syntax of Matchers.
Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should !== (<pivot> +- <tolerance>)” syntax of Matchers.
right
the Spread[T] against which to compare the left-hand value
returns
a TripleEqualsInvocationOnSpread wrapping the passed Spread[T] value, with expectingEqual set to false.
def !==(right: Null): TripleEqualsInvocation[Null]
Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should !== null” syntax of Matchers.
Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should !== null” syntax of Matchers.
right
a null reference
returns
a TripleEqualsInvocation wrapping the passed null value, with expectingEqual set to false.
def !==[T](right: T): TripleEqualsInvocation[T]
Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should !== <right>” syntax of Matchers.
Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should !== <right>” syntax of Matchers.
right
the right-hand side value for an equality assertion
returns
a TripleEqualsInvocation wrapping the passed right value, with expectingEqual set to false.
final def ##: Int
Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean
Definition Classes
AnyRef → Any
def ===[T](right: Spread[T]): TripleEqualsInvocationOnSpread[T]
Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should === (<pivot> +- <tolerance>)” syntax of Matchers.
Returns a TripleEqualsInvocationOnSpread[T], given an Spread[T], to facilitate the “<left> should === (<pivot> +- <tolerance>)” syntax of Matchers.
right
the Spread[T] against which to compare the left-hand value
returns
a TripleEqualsInvocationOnSpread wrapping the passed Spread[T] value, with expectingEqual set to true.
def ===(right: Null): TripleEqualsInvocation[Null]
Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should === null” syntax of Matchers.
Returns a TripleEqualsInvocation[Null], given a null reference, to facilitate the “<left> should === null” syntax of Matchers.
right
a null reference
returns
a TripleEqualsInvocation wrapping the passed null value, with expectingEqual set to true.
def ===[T](right: T): TripleEqualsInvocation[T]
Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should === <right>” syntax of Matchers.
Returns a TripleEqualsInvocation[T], given an object of type T, to facilitate the “<left> should === <right>” syntax of Matchers.
right
the right-hand side value for an equality assertion
returns
a TripleEqualsInvocation wrapping the passed right value, with expectingEqual set to true.
final def asInstanceOf[T0]: T0
Definition Classes
Any
def clone(): AnyRef
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.CloneNotSupportedException]) @native()
def defaultEquality[A]: Equality[A]
Returns an Equality[A] for any type A that determines equality by first calling .deep on any Array (on either the left or right side), then comparing the resulting objects with ==.
Returns an Equality[A] for any type A that determines equality by first calling .deep on any Array (on either the left or right side), then comparing the resulting objects with ==.
returns
a default Equality for type A
final def eq(arg0: AnyRef): Boolean
Definition Classes
AnyRef
def equals(arg0: AnyRef): Boolean
Definition Classes
AnyRef → Any
def finalize(): Unit
Attributes
protected[lang]
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.Throwable])
final def getClass(): Class[_ <: AnyRef]
Definition Classes
AnyRef → Any
Annotations
@native()
def hashCode(): Int
Definition Classes
AnyRef → Any
Annotations
@native()
final def isInstanceOf[T0]: Boolean
Definition Classes
Any
final def ne(arg0: AnyRef): Boolean
Definition Classes
AnyRef
final def notify(): Unit
Definition Classes
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@native()
final def notifyAll(): Unit
Definition Classes
AnyRef
Annotations
@native()
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(classOf[java.lang.InterruptedException])
final def wait(arg0: Long, arg1: Int): Unit
Definition Classes
AnyRef
Annotations
@throws(classOf[java.lang.InterruptedException])
final def wait(arg0: Long): Unit
Definition Classes
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Annotations
@throws(classOf[java.lang.InterruptedException]) @native()

Packages

TripleEqualsSupport

Companion object TripleEqualsSupport

trait TripleEqualsSupport extends AnyRef

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TripleEqualsSupport

Companion object TripleEqualsSupport

trait TripleEqualsSupport extends AnyRef

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TripleEqualsSupport