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