47 lines
1.3 KiB
Java
47 lines
1.3 KiB
Java
/*
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* Copyright 2014 JetBrains s.r.o.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package jetbrains.mps.unification;
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import java.util.Collection;
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/**
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* Represents a node in a term graph. The graph may contain cycles. A node in a term
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* graph can be of three kinds: a variable, a function (possibly constant) and a reference.
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* A reference must point to either a function term or a variable.
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*
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* A term must implement {@link java.lang.Comparable}, but this is only really used for
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* comparing the variables.
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*
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* @author Fedor Isakov
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*/
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public interface Term extends Comparable<Term> {
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Object symbol();
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Collection<? extends Term> arguments();
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Term get();
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boolean is(Kind kind);
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public enum Kind {
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FUN,
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VAR,
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REF
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}
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}
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