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 org.jetbrains.annotations.NotNull;
020    import org.jetbrains.jet.lang.types.JetType;
021    import org.jetbrains.jet.lang.types.TypeConstructor;
022    
023    public class JetTypeChecker {
024    
025        public interface TypeConstructorEquality {
026            boolean equals(@NotNull TypeConstructor a, @NotNull TypeConstructor b);
027        }
028    
029        public static final JetTypeChecker DEFAULT = new JetTypeChecker(new TypeCheckingProcedure(new TypeCheckerTypingConstraints()));
030    
031        public static final JetTypeChecker FLEXIBLE_UNEQUAL_TO_INFLEXIBLE = new JetTypeChecker(new TypeCheckingProcedure(new TypeCheckerTypingConstraints()) {
032            @Override
033            protected boolean heterogeneousEquivalence(JetType inflexibleType, JetType flexibleType) {
034                return false;
035            }
036        });
037    
038        @NotNull
039        public static JetTypeChecker withAxioms(@NotNull final TypeConstructorEquality equalityAxioms) {
040            return new JetTypeChecker(new TypeCheckingProcedure(new TypeCheckerTypingConstraints() {
041                @Override
042                public boolean assertEqualTypeConstructors(@NotNull TypeConstructor constructor1, @NotNull TypeConstructor constructor2) {
043                    return constructor1.equals(constructor2) || equalityAxioms.equals(constructor1, constructor2);
044                }
045            }));
046        }
047    
048        private final TypeCheckingProcedure procedure;
049    
050        private JetTypeChecker(@NotNull TypeCheckingProcedure procedure) {
051            this.procedure = procedure;
052        }
053    
054        public boolean isSubtypeOf(@NotNull JetType subtype, @NotNull JetType supertype) {
055            return procedure.isSubtypeOf(subtype, supertype);
056        }
057    
058        public boolean equalTypes(@NotNull JetType a, @NotNull JetType b) {
059            return procedure.equalTypes(a, b);
060        }
061    }