org.apache.calcite.tools.RuleSets.java Source code

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Here is the source code for org.apache.calcite.tools.RuleSets.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.calcite.tools;

import org.apache.calcite.plan.RelOptRule;

import com.google.common.collect.ImmutableList;

import java.util.Iterator;

/**
 * Utilities for creating and composing rule sets.
 *
 * @see org.apache.calcite.tools.RuleSet
 */
public class RuleSets {
    private RuleSets() {
    }

    /** Creates a rule set with a given array of rules. */
    public static RuleSet ofList(RelOptRule... rules) {
        return new ListRuleSet(ImmutableList.copyOf(rules));
    }

    /** Creates a rule set with a given collection of rules. */
    public static RuleSet ofList(Iterable<? extends RelOptRule> rules) {
        return new ListRuleSet(ImmutableList.copyOf(rules));
    }

    /** Rule set that consists of a list of rules. */
    private static class ListRuleSet implements RuleSet {
        private final ImmutableList<RelOptRule> rules;

        public ListRuleSet(ImmutableList<RelOptRule> rules) {
            this.rules = rules;
        }

        @Override
        public int hashCode() {
            return rules.hashCode();
        }

        @Override
        public boolean equals(Object obj) {
            return obj == this || obj instanceof ListRuleSet && rules.equals(((ListRuleSet) obj).rules);
        }

        public Iterator<RelOptRule> iterator() {
            return rules.iterator();
        }
    }
}

// End RuleSets.java