001    /*
002     * Copyright 2010-2013 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.lang.types.checker;
018    
019    import com.google.common.collect.BiMap;
020    import com.google.common.collect.HashBiMap;
021    import org.jetbrains.annotations.NotNull;
022    import org.jetbrains.jet.lang.types.JetType;
023    import org.jetbrains.jet.lang.types.TypeConstructor;
024    
025    public class JetTypeChecker {
026    
027        public static final JetTypeChecker INSTANCE = new JetTypeChecker();
028        public static final HashBiMap<TypeConstructor, TypeConstructor> EMPTY_AXIOMS = HashBiMap.create();
029    
030        private JetTypeChecker() {
031        }
032    
033        public boolean isSubtypeOf(@NotNull JetType subtype, @NotNull JetType supertype) {
034    //        return new TypeCheckingProcedure().run(subtype, supertype);
035            return TYPE_CHECKER.isSubtypeOf(subtype, supertype);
036        }
037    
038        public boolean equalTypes(@NotNull JetType a, @NotNull JetType b) {
039            return TYPE_CHECKER.equalTypes(a, b);
040        }
041    
042        public boolean equalTypes(@NotNull JetType a, @NotNull JetType b, @NotNull final BiMap<TypeConstructor, TypeConstructor> equalityAxioms) {
043            return new TypeCheckingProcedure(new TypeCheckerTypingConstraints() {
044                @Override
045                public boolean assertEqualTypeConstructors(@NotNull TypeConstructor constructor1, @NotNull TypeConstructor constructor2) {
046                    if (!constructor1.equals(constructor2)) {
047                        TypeConstructor img1 = equalityAxioms.get(constructor1);
048                        TypeConstructor img2 = equalityAxioms.get(constructor2);
049                        if (!(img1 != null && img1.equals(constructor2)) &&
050                                !(img2 != null && img2.equals(constructor1))) {
051                            return false;
052                        }
053                    }
054                    return true;
055                }
056            }).equalTypes(a, b);
057        }
058    
059        private static final TypeCheckingProcedure TYPE_CHECKER = new TypeCheckingProcedure(new TypeCheckerTypingConstraints());
060    
061        private static class TypeCheckerTypingConstraints implements TypingConstraints {
062            @Override
063            public boolean assertEqualTypes(@NotNull JetType a, @NotNull JetType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
064                return typeCheckingProcedure.equalTypes(a, b);
065    //            return TypeUtils.equalTypes(a, b);
066            }
067    
068            @Override
069            public boolean assertEqualTypeConstructors(@NotNull TypeConstructor a, @NotNull TypeConstructor b) {
070                return a.equals(b);
071            }
072    
073            @Override
074            public boolean assertSubtype(@NotNull JetType subtype, @NotNull JetType supertype, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
075                return typeCheckingProcedure.isSubtypeOf(subtype, supertype);
076            }
077    
078            @Override
079            public boolean noCorrespondingSupertype(@NotNull JetType subtype, @NotNull JetType supertype) {
080                return false; // type checking fails
081            }
082        }
083    }