Uniformity

Indicates whether this Uniformity's normalized method can “handle” the passed object, if cast to the appropriate type A.

If this method returns true for a particular passed object, it means that if the object is passed to normalizedOrSame, that method will return the result of passing it to normalized. It does not mean that the object will necessarily be modified when passed to normalizedOrSame or normalized. For example, the lowerCased field of StringNormalizations is a Uniformity[String] that normalizes strings by forcing all characters to lower case:

scala> import org.scalactic._
import org.scalactic._

scala> import StringNormalizations._
import StringNormalizations._

scala> lowerCased
res0: org.scalactic.Uniformity[String] = lowerCased

scala> lowerCased.normalized("HALLOOO!")
res1: String = hallooo!

Now consider two strings held from variables of type AnyRef:

scala> val yell: AnyRef = "HOWDY"
yell: AnyRef = HOWDY

scala> val whisper: AnyRef = "howdy"
whisper: AnyRef = howdy

As you would expect, when yell is passed to normalizedCanHandle, it returns true, and when yell is passed to normalizedOrSame, it returns a lower-cased (normal) form:

scala> lowerCased.normalizedCanHandle(yell)
res2: Boolean = true

scala> lowerCased.normalizedOrSame(yell)
res3: Any = howdy

A similar thing happens, however, when whisper is passed to normalizedCanHandle and normalizedOrSame, even though in this case the string is already in normal form according to the lowerCased Uniformity:

scala> lowerCased.normalizedCanHandle(whisper)
res4: Boolean = true

scala> lowerCased.normalizedOrSame(whisper)
res5: Any = howdy

This illustrates that normalizedCanHandle does not indicate that the passed object is not in normalized form already, just that it can be be handled by the normalized method. This further means that the normalized method itself simply ensures that objects are returned in normal form. It need not necessarily change them: if a passed object is already in normal form, normalized can (and usually should) return the exact same object. That is in fact what happened when we normalized whisper. Since whisper's value of "hello" was already in normal form (all lower-cased), normalized ( invoked by the normalizedOrSame method) returned the exact same object passed:

scala> val whisperNormed = res5.asInstanceOf[AnyRef]
whisperNormed: AnyRef = howdy

scala> whisperNormed eq whisper
res8: Boolean = true

Returns either the result of passing this object to normalized, if appropriate, or the same object.

Implementations can decide what “appropriate” means, but the intent is that it will usually mean the value passed is of the type A. For example, if this is a Uniformity[String], appropriate means that the value (of type Any) passed is actually an instance of String. Because of erasure, however, a Uniformity[List[String]] will only be able to tell whether a value is a List[_], so it might declare any List[_] that contains only Strings (determined by invoking isInstanceOf[String] on each element) to be appropriate. This means a Uniformity[List[String]] might normalize a List[AnyRef] that happens to contain only Strings.

Returns a new Uniformity that combines this and the passed Uniformity.

The normalized and normalizedOrSame methods of the Uniformity returned by this method return a result obtained by forwarding the passed value first to this Uniformity's implementation of the method, then passing that result to the other Uniformity's implementation of the method, respectively. Essentially, the body of the composed normalized method is:

uniformityPassedToAnd.normalized(uniformityOnWhichAndWasInvoked.normalized(a))

And the body of the composed normalizedOrSame method is:

uniformityPassedToAnd.normalizedOrSame(uniformityOnWhichAndWasInvoked.normalizedOrSame(a))

The normalizeCanHandle method of the Uniformity returned by this method returns a result obtained by anding the result of forwarding the passed value to this Uniformity's implementation of the method with the result of forwarding it to the passed Uniformity's implementation. Essentially, the body of the composed normalizeCanHandle method is:

uniformityOnWhichAndWasInvoked.normalizeCanHandle(a) && uniformityPassedToAnd.normalizeCanHandle(a)

Converts this Uniformity to a NormalizingEquality[A] whose normalized, normalizedCanHandle, and normalizedOrSame methods delegate to this Uniformity[A] and whose afterNormalizationEquality field returns the implicitly passed Equality[A].

Returns a new Normalization that composes this and the passed Normalization.

The normalized method of the Normalization returned by this method returns a normalized form of the passed object obtained by forwarding the passed value first to this Normalization's normalized method, then passing that result to the other Normalization's normalized method. Essentially, the body of the composed normalized method is:

normalizationPassedToAnd.normalized(normalizationOnWhichAndWasInvoked.normalized(a))

Returns a normalized form of the passed object.

If the passed object is already in normal form, this method may return the same instance passed.

Converts this Normalization to a NormalizingEquivalence[A] whose normalized method delegates to this Normalization[A] and whose afterNormalizationEquivalence field returns the implicitly passed Equivalence[A].