/*
* Copyright 2010-2015 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jetbrains.kotlin.util.collectionUtils
import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
import java.util.*
/**
* Concatenates the contents of this collection with the given collection, avoiding allocations if possible.
* Can modify `this` if it is a mutable collection.
*/
fun <T> Collection<T>?.concat(collection: Collection<T>): Collection<T>? {
if (collection.isEmpty()) {
return this
}
if (this == null) {
return collection
}
if (this is LinkedHashSet) {
addAll(collection)
return this
}
val result = LinkedHashSet(this)
result.addAll(collection)
return result
}
fun <T> concatInOrder(c1: Collection<T>?, c2: Collection<T>?): Collection<T> {
val result = if (c1 == null || c1.isEmpty())
c2
else if (c2 == null || c2.isEmpty())
c1
else {
val result = LinkedHashSet<T>()
result.addAll(c1)
result.addAll(c2)
result
}
return result ?: emptySet()
}
inline fun <Scope, T> getFromAllScopes(scopes: List<Scope>, callback: (Scope) -> Collection<T>): Collection<T> {
if (scopes.isEmpty()) return emptySet()
var result: Collection<T>? = null
for (scope in scopes) {
result = result.concat(callback(scope))
}
return result ?: emptySet()
}
inline fun <Scope, T> getFromAllScopes(firstScope: Scope, restScopes: List<Scope>, callback: (Scope) -> Collection<T>): Collection<T> {
var result: Collection<T>? = callback(firstScope)
for (scope in restScopes) {
result = result.concat(callback(scope))
}
return result ?: emptySet()
}
inline fun <Scope, T : ClassifierDescriptor> getFirstClassifierDiscriminateHeaders(scopes: List<Scope>, callback: (Scope) -> T?): T? {
// NOTE: This is performance-sensitive; please don't replace with map().firstOrNull()
var result: T? = null
for (scope in scopes) {
val newResult = callback(scope)
if (newResult != null) {
if (newResult is ClassifierDescriptorWithTypeParameters && newResult.isExpect) {
if (result == null) result = newResult
}
// this class is Impl or usual class
else {
return newResult
}
}
}
return result
}