mirror of https://github.com/DanilaFe/abacus
26 lines
954 B
Kotlin
26 lines
954 B
Kotlin
package org.nwapw.abacus.context
|
|
|
|
import kotlin.reflect.KProperty
|
|
|
|
/**
|
|
* A delegate to accumulate a collection of elements in a [ReductionContext] hierarchy.
|
|
*
|
|
* ChainAccumulateDelegate is similar to the [ChainSearchDelegate], however, it operates only on collections.
|
|
* Instead of returning the most recent collection, it merges them into a [Set].
|
|
*
|
|
* @param T the type of element in the collection.
|
|
* @property valueGetter the getter used to access the collection from the context.
|
|
*/
|
|
class ChainAccumulateDelegate<out T>(private val valueGetter: ReductionContext.() -> Collection<T>) {
|
|
|
|
operator fun getValue(selfRef: Any, property: KProperty<*>): Set<T> {
|
|
val set = mutableSetOf<T>()
|
|
var currentRef: ReductionContext = selfRef as? ReductionContext ?: return set
|
|
while(true) {
|
|
set.addAll(currentRef.valueGetter())
|
|
currentRef = currentRef.parent ?: break
|
|
}
|
|
return set
|
|
}
|
|
|
|
} |