kotlin.reflect.full.KClasses.kt Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of kotlin-reflect Show documentation
Show all versions of kotlin-reflect Show documentation
Kotlin Full Reflection Library
/*
* Copyright 2010-2016 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.
*/
@file:JvmName("KClasses")
@file:Suppress("UNCHECKED_CAST")
package kotlin.reflect.full
import org.jetbrains.kotlin.descriptors.ConstructorDescriptor
import org.jetbrains.kotlin.types.TypeSubstitutor
import org.jetbrains.kotlin.types.Variance
import org.jetbrains.kotlin.utils.DFS
import kotlin.reflect.*
import kotlin.reflect.jvm.internal.KCallableImpl
import kotlin.reflect.jvm.internal.KClassImpl
import kotlin.reflect.jvm.internal.KFunctionImpl
import kotlin.reflect.jvm.internal.KTypeImpl
import kotlin.reflect.jvm.internal.KotlinReflectionInternalError
/**
* Returns the primary constructor of this class, or `null` if this class has no primary constructor.
* See the [Kotlin language documentation](http://kotlinlang.org/docs/reference/classes.html#constructors)
* for more information.
*/
@SinceKotlin("1.1")
val KClass.primaryConstructor: KFunction?
get() = (this as KClassImpl).constructors.firstOrNull {
((it as KFunctionImpl).descriptor as ConstructorDescriptor).isPrimary
}
/**
* Returns a [KClass] instance representing the companion object of a given class,
* or `null` if the class doesn't have a companion object.
*/
@SinceKotlin("1.1")
val KClass<*>.companionObject: KClass<*>?
get() = nestedClasses.firstOrNull {
(it as KClassImpl<*>).descriptor.isCompanionObject
}
/**
* Returns an instance of the companion object of a given class,
* or `null` if the class doesn't have a companion object.
*/
@SinceKotlin("1.1")
val KClass<*>.companionObjectInstance: Any?
get() = companionObject?.objectInstance
/**
* Returns a type corresponding to the given class with type parameters of that class substituted as the corresponding arguments.
* For example, for class `MyMap` [defaultType] would return the type `MyMap`.
*/
@Deprecated("This function creates a type which rarely makes sense for generic classes. " +
"For example, such type can only be used in signatures of members of that class. " +
"Use starProjectedType or createType() for clearer semantics.")
@SinceKotlin("1.1")
val KClass<*>.defaultType: KType
get() = KTypeImpl((this as KClassImpl<*>).descriptor.defaultType) { jClass }
/**
* Returns all functions and properties declared in this class.
* Does not include members declared in supertypes.
*/
@SinceKotlin("1.1")
val KClass<*>.declaredMembers: Collection>
get() = (this as KClassImpl).data().declaredMembers
/**
* Returns all functions declared in this class, including all non-static methods declared in the class
* and the superclasses, as well as static methods declared in the class.
*/
@SinceKotlin("1.1")
val KClass<*>.functions: Collection>
get() = members.filterIsInstance>()
/**
* Returns static functions declared in this class.
*/
@SinceKotlin("1.1")
val KClass<*>.staticFunctions: Collection>
get() = (this as KClassImpl).data().allStaticMembers.filterIsInstance>()
/**
* Returns non-extension non-static functions declared in this class and all of its superclasses.
*/
@SinceKotlin("1.1")
val KClass<*>.memberFunctions: Collection>
get() = (this as KClassImpl).data().allNonStaticMembers.filter { it.isNotExtension && it is KFunction<*> } as Collection>
/**
* Returns extension functions declared in this class and all of its superclasses.
*/
@SinceKotlin("1.1")
val KClass<*>.memberExtensionFunctions: Collection>
get() = (this as KClassImpl).data().allNonStaticMembers.filter { it.isExtension && it is KFunction<*> } as Collection>
/**
* Returns all functions declared in this class.
* If this is a Java class, it includes all non-static methods (both extensions and non-extensions)
* declared in the class and the superclasses, as well as static methods declared in the class.
*/
@SinceKotlin("1.1")
val KClass<*>.declaredFunctions: Collection>
get() = (this as KClassImpl).data().declaredMembers.filterIsInstance>()
/**
* Returns non-extension non-static functions declared in this class.
*/
@SinceKotlin("1.1")
val KClass<*>.declaredMemberFunctions: Collection>
get() = (this as KClassImpl).data().declaredNonStaticMembers.filter { it.isNotExtension && it is KFunction<*> } as Collection>
/**
* Returns extension functions declared in this class.
*/
@SinceKotlin("1.1")
val KClass<*>.declaredMemberExtensionFunctions: Collection>
get() = (this as KClassImpl).data().declaredNonStaticMembers.filter { it.isExtension && it is KFunction<*> } as Collection>
/**
* Returns static properties declared in this class.
* Only properties representing static fields of Java classes are considered static.
*/
@SinceKotlin("1.1")
val KClass<*>.staticProperties: Collection>
get() = (this as KClassImpl).data().allStaticMembers.filter { it.isNotExtension && it is KProperty0<*> } as Collection>
/**
* Returns non-extension properties declared in this class and all of its superclasses.
*/
@SinceKotlin("1.1")
val KClass.memberProperties: Collection>
get() = (this as KClassImpl).data().allNonStaticMembers.filter { it.isNotExtension && it is KProperty1<*, *> } as Collection>
/**
* Returns extension properties declared in this class and all of its superclasses.
*/
@SinceKotlin("1.1")
val KClass.memberExtensionProperties: Collection>
get() = (this as KClassImpl).data().allNonStaticMembers.filter { it.isExtension && it is KProperty2<*, *, *> } as Collection>
/**
* Returns non-extension properties declared in this class.
*/
@SinceKotlin("1.1")
val KClass.declaredMemberProperties: Collection>
get() = (this as KClassImpl).data().declaredNonStaticMembers.filter { it.isNotExtension && it is KProperty1<*, *> } as Collection>
/**
* Returns extension properties declared in this class.
*/
@SinceKotlin("1.1")
val KClass.declaredMemberExtensionProperties: Collection>
get() = (this as KClassImpl).data().declaredNonStaticMembers.filter { it.isExtension && it is KProperty2<*, *, *> } as Collection>
private val KCallableImpl<*>.isExtension: Boolean
get() = descriptor.extensionReceiverParameter != null
private val KCallableImpl<*>.isNotExtension: Boolean
get() = !isExtension
/**
* Immediate superclasses of this class, in the order they are listed in the source code.
* Includes superclasses and superinterfaces of the class, but does not include the class itself.
*/
@SinceKotlin("1.1")
val KClass<*>.superclasses: List>
get() = supertypes.mapNotNull { it.classifier as? KClass<*> }
/**
* All supertypes of this class, including indirect ones, in no particular order.
* There is not more than one type in the returned collection that has any given classifier.
*/
@SinceKotlin("1.1")
val KClass<*>.allSupertypes: Collection
get() = DFS.dfs(
supertypes,
DFS.Neighbors { current ->
val klass = current.classifier as? KClass<*> ?: throw KotlinReflectionInternalError("Supertype not a class: $current")
val supertypes = klass.supertypes
val typeArguments = current.arguments
if (typeArguments.isEmpty()) supertypes
else TypeSubstitutor.create((current as KTypeImpl).type).let { substitutor ->
supertypes.map { supertype ->
val substituted = substitutor.substitute((supertype as KTypeImpl).type, Variance.INVARIANT)
?: throw KotlinReflectionInternalError("Type substitution failed: $supertype ($current)")
KTypeImpl(substituted)
}
}
},
DFS.VisitedWithSet(),
object : DFS.NodeHandlerWithListResult() {
override fun beforeChildren(current: KType): Boolean {
result.add(current)
return true
}
}
)
/**
* All superclasses of this class, including indirect ones, in no particular order.
* Includes superclasses and superinterfaces of the class, but does not include the class itself.
* The returned collection does not contain more than one instance of any given class.
*/
@SinceKotlin("1.1")
val KClass<*>.allSuperclasses: Collection>
get() = allSupertypes.map { supertype ->
supertype.classifier as? KClass<*> ?: throw KotlinReflectionInternalError("Supertype not a class: $supertype")
}
/**
* Returns `true` if `this` class is the same or is a (possibly indirect) subclass of [base], `false` otherwise.
*/
@SinceKotlin("1.1")
fun KClass<*>.isSubclassOf(base: KClass<*>): Boolean =
this == base ||
DFS.ifAny(listOf(this), KClass<*>::superclasses) { it == base }
/**
* Returns `true` if `this` class is the same or is a (possibly indirect) superclass of [derived], `false` otherwise.
*/
@SinceKotlin("1.1")
fun KClass<*>.isSuperclassOf(derived: KClass<*>): Boolean =
derived.isSubclassOf(this)
/**
* Casts the given [value] to the class represented by this [KClass] object.
* Throws an exception if the value is `null` or if it is not an instance of this class.
*
* @see [KClass.isInstance]
* @see [KClass.safeCast]
*/
@SinceKotlin("1.1")
fun KClass.cast(value: Any?): T {
if (!isInstance(value)) throw TypeCastException("Value cannot be cast to $qualifiedName")
return value as T
}
/**
* Casts the given [value] to the class represented by this [KClass] object.
* Returns `null` if the value is `null` or if it is not an instance of this class.
*
* @see [KClass.isInstance]
* @see [KClass.cast]
*/
@SinceKotlin("1.1")
fun KClass.safeCast(value: Any?): T? {
return if (isInstance(value)) value as T else null
}
/**
* Creates a new instance of the class, calling a constructor which either has no parameters or all parameters of which are optional
* (see [KParameter.isOptional]). If there are no or many such constructors, an exception is thrown.
*/
@SinceKotlin("1.1")
fun KClass.createInstance(): T {
// TODO: throw a meaningful exception
val noArgsConstructor = constructors.singleOrNull { it.parameters.all(KParameter::isOptional) }
?: throw IllegalArgumentException("Class should have a single no-arg constructor: $this")
return noArgsConstructor.callBy(emptyMap())
}