1 /* 2 * Copyright 2017 Google Inc. All Rights Reserved. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.turbine.binder.lookup; 18 19 import com.google.turbine.binder.sym.ClassSymbol; 20 import com.google.turbine.tree.Tree; 21 import org.jspecify.nullness.Nullable; 22 23 /** 24 * A scope for imports. Non-canonical imports depend on hierarchy analysis, so to break the cycle we 25 * defer non-canonical resolution to a {@link ResolveFunction} that is provided once hierarchy 26 * analysis is underway. 27 */ 28 public interface ImportScope { 29 30 /** 31 * A function that performs non-canonical resolution, see {@link 32 * com.google.turbine.binder.Resolve#resolve}. 33 */ 34 @FunctionalInterface 35 interface ResolveFunction { 36 @Nullable resolveOne(ClassSymbol base, Tree.Ident name)37 ClassSymbol resolveOne(ClassSymbol base, Tree.Ident name); 38 } 39 40 /** See {@link Scope#lookup(LookupKey)}. */ 41 @Nullable lookup(LookupKey lookupKey, ResolveFunction resolve)42 LookupResult lookup(LookupKey lookupKey, ResolveFunction resolve); 43 44 /** Adds a scope to the chain, in the manner of {@link CompoundScope#append(Scope)}. */ append(ImportScope next)45 default ImportScope append(ImportScope next) { 46 return new ImportScope() { 47 @Override 48 public @Nullable LookupResult lookup(LookupKey lookupKey, ResolveFunction resolve) { 49 LookupResult result = next.lookup(lookupKey, resolve); 50 if (result != null) { 51 return result; 52 } 53 return ImportScope.this.lookup(lookupKey, resolve); 54 } 55 }; 56 } 57 58 /** 59 * Creates a trivial {@link ImportScope} from a {@link Scope}, which ignores the provided {@link 60 * ResolveFunction} and calls the underlying scope's lookup method. Used to chain {@link Scope}s 61 * and {@link ImportScope}s together. 62 */ 63 static ImportScope fromScope(Scope scope) { 64 return new ImportScope() { 65 @Override 66 public @Nullable LookupResult lookup(LookupKey lookupKey, ResolveFunction resolve) { 67 return scope.lookup(lookupKey); 68 } 69 }; 70 } 71 72 /** Partially applies the given {@link ResolveFunction} to this {@link ImportScope}. */ 73 default CompoundScope toScope(ResolveFunction resolve) { 74 return CompoundScope.base( 75 new Scope() { 76 @Override 77 public @Nullable LookupResult lookup(LookupKey lookupKey) { 78 return ImportScope.this.lookup(lookupKey, resolve); 79 } 80 }); 81 } 82 } 83