Analysis API: simplify scope hierarchy

analysis/analysis-api-impl-base/src/org/jetbrains/kotlin/analysis/api/impl/base/scopes/KtCompositeScope.kt

@@ -5,23 +5,17 @@
 
 package org.jetbrains.kotlin.analysis.api.impl.base.scopes
 
-import org.jetbrains.kotlin.analysis.api.ValidityTokenOwner
-import org.jetbrains.kotlin.analysis.api.scopes.KtCompositeScope
 import org.jetbrains.kotlin.analysis.api.scopes.KtScope
 import org.jetbrains.kotlin.analysis.api.scopes.KtScopeNameFilter
-import org.jetbrains.kotlin.analysis.api.symbols.KtCallableSymbol
-import org.jetbrains.kotlin.analysis.api.symbols.KtClassifierSymbol
-import org.jetbrains.kotlin.analysis.api.symbols.KtConstructorSymbol
-import org.jetbrains.kotlin.analysis.api.symbols.KtSymbol
+import org.jetbrains.kotlin.analysis.api.symbols.*
 import org.jetbrains.kotlin.analysis.api.tokens.ValidityToken
 import org.jetbrains.kotlin.analysis.api.withValidityAssertion
 import org.jetbrains.kotlin.name.Name
 
-@OptIn(ExperimentalStdlibApi::class)
-class SimpleKtCompositeScope(
-    override val subScopes: List<KtScope>,
+class KtCompositeScope(
+    private val subScopes: List<KtScope>,
     override val token: ValidityToken
-) : KtCompositeScope, ValidityTokenOwner {
+) : KtScope {
     override fun getAllPossibleNames(): Set<Name> = withValidityAssertion {
         buildSet {
             subScopes.flatMapTo(this) { it.getAllPossibleNames() }
@@ -64,6 +58,12 @@ class SimpleKtCompositeScope(
         }
     }
 
+    override fun getPackageSymbols(nameFilter: KtScopeNameFilter): Sequence<KtPackageSymbol> = withValidityAssertion {
+        sequence {
+            subScopes.forEach { yieldAll(it.getPackageSymbols(nameFilter)) }
+        }
+    }
+
     override fun mayContainName(name: Name): Boolean = withValidityAssertion {
         subScopes.any { it.mayContainName(name) }
     }

analysis/analysis-api-impl-base/src/org/jetbrains/kotlin/analysis/api/impl/base/scopes/KtEmptyScope.kt

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.analysis.api.impl.base.scopes
+
+import org.jetbrains.kotlin.analysis.api.scopes.KtScope
+import org.jetbrains.kotlin.analysis.api.scopes.KtScopeNameFilter
+import org.jetbrains.kotlin.analysis.api.symbols.*
+import org.jetbrains.kotlin.analysis.api.tokens.ValidityToken
+import org.jetbrains.kotlin.analysis.api.withValidityAssertion
+import org.jetbrains.kotlin.name.Name
+
+class KtEmptyScope(override val token: ValidityToken) : KtScope {
+    override fun getAllPossibleNames(): Set<Name> = withValidityAssertion {
+        return emptySet()
+    }
+
+    override fun getPossibleCallableNames(): Set<Name> = withValidityAssertion {
+        return emptySet()
+    }
+
+    override fun getPossibleClassifierNames(): Set<Name> = withValidityAssertion {
+        return emptySet()
+    }
+
+    override fun getAllSymbols(): Sequence<KtSymbol> = withValidityAssertion {
+        return emptySequence()
+    }
+
+    override fun getCallableSymbols(nameFilter: KtScopeNameFilter): Sequence<KtCallableSymbol> = withValidityAssertion {
+        return emptySequence()
+    }
+
+    override fun getClassifierSymbols(nameFilter: KtScopeNameFilter): Sequence<KtClassifierSymbol> = withValidityAssertion {
+        return emptySequence()
+    }
+
+    override fun getConstructors(): Sequence<KtConstructorSymbol> = withValidityAssertion {
+        return emptySequence()
+    }
+
+    override fun getPackageSymbols(nameFilter: KtScopeNameFilter): Sequence<KtPackageSymbol> = withValidityAssertion {
+        emptySequence()
+    }
+
+    override fun mayContainName(name: Name): Boolean = withValidityAssertion {
+        return false
+    }
+}