org.jetbrains.kotlin.types.StarProjectionImpl.kt Maven / Gradle / Ivy
/*
* 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.types
import org.jetbrains.kotlin.builtins.KotlinBuiltIns
import org.jetbrains.kotlin.descriptors.ClassifierDescriptorWithTypeParameters
import org.jetbrains.kotlin.descriptors.FunctionDescriptor
import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
import org.jetbrains.kotlin.resolve.descriptorUtil.builtIns
import org.jetbrains.kotlin.types.checker.KotlinTypeRefiner
class StarProjectionImpl(
private val typeParameter: TypeParameterDescriptor
) : TypeProjectionBase() {
override fun isStarProjection() = true
override fun getProjectionKind() = Variance.OUT_VARIANCE
// No synchronization here: there's no problem in accidentally computing this twice
private val _type: KotlinType by lazy(LazyThreadSafetyMode.PUBLICATION) {
typeParameter.starProjectionType()
}
override fun getType() = _type
@TypeRefinement
override fun refine(kotlinTypeRefiner: KotlinTypeRefiner): TypeProjection = this
override fun replaceType(type: KotlinType): TypeProjection {
throw UnsupportedOperationException("Replacing type for star projection is unsupported")
}
}
private fun buildStarProjectionTypeByTypeParameters(
typeParameters: List,
upperBounds: List,
builtIns: KotlinBuiltIns
) = TypeSubstitutor.create(
object : TypeConstructorSubstitution() {
override fun get(key: TypeConstructor) =
if (key in typeParameters)
TypeUtils.makeStarProjection(key.declarationDescriptor as TypeParameterDescriptor)
else null
}
).substitute(upperBounds.first(), Variance.OUT_VARIANCE) ?: builtIns.defaultBound
fun TypeParameterDescriptor.starProjectionType(): KotlinType {
return when (val descriptor = this.containingDeclaration) {
is ClassifierDescriptorWithTypeParameters -> {
buildStarProjectionTypeByTypeParameters(
typeParameters = descriptor.typeConstructor.parameters.map { it.typeConstructor },
upperBounds,
builtIns
)
}
is FunctionDescriptor -> {
buildStarProjectionTypeByTypeParameters(
typeParameters = descriptor.typeParameters.map { it.typeConstructor },
upperBounds,
builtIns
)
}
else -> throw IllegalArgumentException("Unsupported descriptor type to build star projection type based on type parameters of it")
}
}
// It should only be used in rare cases when type parameter for the relevant argument is not available
class StarProjectionForAbsentTypeParameter(
kotlinBuiltIns: KotlinBuiltIns
) : TypeProjectionBase() {
private val nullableAnyType: KotlinType = kotlinBuiltIns.nullableAnyType
override fun isStarProjection() = true
override fun getProjectionKind() = Variance.OUT_VARIANCE
override fun getType() = nullableAnyType
@TypeRefinement
override fun refine(kotlinTypeRefiner: KotlinTypeRefiner): TypeProjection = this
override fun replaceType(type: KotlinType): TypeProjection {
throw UnsupportedOperationException("Replacing type for star projection is unsupported")
}
}