001    /*
002     * Copyright 2010-2015 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.kotlin.types.checker;
018    
019    import org.jetbrains.annotations.NotNull;
020    import org.jetbrains.kotlin.types.KotlinType;
021    import org.jetbrains.kotlin.types.TypeConstructor;
022    
023    public class KotlinTypeChecker {
024    
025        public interface TypeConstructorEquality {
026            boolean equals(@NotNull TypeConstructor a, @NotNull TypeConstructor b);
027        }
028    
029        public static final KotlinTypeChecker DEFAULT = new KotlinTypeChecker(new TypeCheckingProcedure(new TypeCheckerProcedureCallbacksImpl()));
030    
031        public static final KotlinTypeChecker ERROR_TYPES_ARE_EQUAL_TO_ANYTHING = new KotlinTypeChecker(new TypeCheckingProcedure(new TypeCheckerProcedureCallbacksImpl() {
032            @Override
033            public boolean assertEqualTypes(@NotNull KotlinType a, @NotNull KotlinType b, @NotNull TypeCheckingProcedure typeCheckingProcedure) {
034                return a.isError() || b.isError() || super.assertEqualTypes(a, b, typeCheckingProcedure);
035            }
036        }));
037    
038        public static final KotlinTypeChecker FLEXIBLE_UNEQUAL_TO_INFLEXIBLE = new KotlinTypeChecker(new TypeCheckingProcedure(new TypeCheckerProcedureCallbacksImpl()) {
039            @Override
040            protected boolean heterogeneousEquivalence(KotlinType inflexibleType, KotlinType flexibleType) {
041                return false;
042            }
043        });
044    
045        @NotNull
046        public static KotlinTypeChecker withAxioms(@NotNull final TypeConstructorEquality equalityAxioms) {
047            return new KotlinTypeChecker(new TypeCheckingProcedure(new TypeCheckerProcedureCallbacksImpl() {
048                @Override
049                public boolean assertEqualTypeConstructors(@NotNull TypeConstructor constructor1, @NotNull TypeConstructor constructor2) {
050                    return constructor1.equals(constructor2) || equalityAxioms.equals(constructor1, constructor2);
051                }
052            }));
053        }
054    
055        private final TypeCheckingProcedure procedure;
056    
057        private KotlinTypeChecker(@NotNull TypeCheckingProcedure procedure) {
058            this.procedure = procedure;
059        }
060    
061        public boolean isSubtypeOf(@NotNull KotlinType subtype, @NotNull KotlinType supertype) {
062            return procedure.isSubtypeOf(subtype, supertype);
063        }
064    
065        public boolean equalTypes(@NotNull KotlinType a, @NotNull KotlinType b) {
066            return procedure.equalTypes(a, b);
067        }
068    }