/**
* Finds the index of a trait of a given type in this set.
*
* @param traitDef Sought trait definition
* @return index of trait, or -1 if not found
*/
private int findIndex(RelTraitDef traitDef) {
for (int i = 0; i < traits.length; i++) {
RelTrait trait = traits[i];
if ((trait != null) && (trait.getTraitDef() == traitDef)) {
return i;
}
}
return -1;
}
/**
* Returns a trait set consisting of the current set plus a new trait.
*
* <p>If the set does not contain a trait of the same {@link RelTraitDef}, the trait is ignored,
* and this trait set is returned.
*
* @param trait the new trait
* @return New set
* @see #plus(RelTrait)
*/
public RelTraitSet replace(RelTrait trait) {
final RelTraitDef traitDef = trait.getTraitDef();
int index = findIndex(traitDef);
if (index < 0) {
// Trait is not present. Ignore it.
return this;
}
return replace(index, trait);
}
/**
* Replaces an existing RelTrait in the set. Returns a different trait set; does not modify this
* trait set.
*
* @param index 0-based index into ordered RelTraitSet
* @param trait the new RelTrait
* @return the old RelTrait at the index
*/
public RelTraitSet replace(int index, RelTrait trait) {
assert traits[index].getTraitDef() == trait.getTraitDef()
: "RelTrait has different RelTraitDef than replacement";
RelTrait canonizedTrait = canonize(trait);
if (traits[index] == canonizedTrait) {
return this;
}
RelTrait[] newTraits = traits.clone();
newTraits[index] = canonizedTrait;
return cache.getOrAdd(new RelTraitSet(cache, newTraits));
}
/**
* Returns this trait set with a given trait added or overridden. Does not modify this trait set.
*
* @param trait Trait
* @return Trait set with given trait
*/
public RelTraitSet plus(RelTrait trait) {
if (contains(trait)) {
return this;
}
int i = findIndex(trait.getTraitDef());
if (i >= 0) {
return replace(i, trait);
}
final RelTrait canonizedTrait = canonize(trait);
RelTrait[] newTraits = Arrays.copyOf(traits, traits.length + 1);
newTraits[newTraits.length - 1] = canonizedTrait;
return cache.getOrAdd(new RelTraitSet(cache, newTraits));
}
/**
* Returns whether this trait set contains the given trait, or whether the trait is not present
* because its {@link RelTraitDef} is not enabled. Returns false if another trait of the same
* {@code RelTraitDef} is present.
*
* @param trait Trait
* @return Whether trait is present, or is absent because disabled
*/
public boolean containsIfApplicable(RelTrait trait) {
// Note that '==' is sufficient, because trait should be canonized.
final RelTrait trait1 = getTrait(trait.getTraitDef());
return trait1 == null || trait1 == trait;
}