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
017package org.jetbrains.jet.lang.types.checker;
018
019import com.google.common.collect.BiMap;
020import com.google.common.collect.HashBiMap;
021import org.jetbrains.annotations.NotNull;
022import org.jetbrains.jet.lang.types.JetType;
023import org.jetbrains.jet.lang.types.TypeConstructor;
024
025public 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}