| /* |
| * 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.hyracks.algebricks.core.algebra.expressions; |
| |
| import java.util.Collection; |
| import java.util.List; |
| |
| import org.apache.commons.lang3.mutable.Mutable; |
| import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalExpressionTag; |
| import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable; |
| import org.apache.hyracks.algebricks.core.algebra.visitors.ILogicalExpressionVisitor; |
| |
| public final class ConstantExpression extends AbstractLogicalExpression { |
| private final IAlgebricksConstantValue value; |
| |
| public static final ConstantExpression TRUE = new ConstantExpression(new IAlgebricksConstantValue() { |
| |
| @Override |
| public boolean isTrue() { |
| return true; |
| } |
| |
| @Override |
| public boolean isMissing() { |
| return false; |
| } |
| |
| @Override |
| public boolean isNull() { |
| return false; |
| } |
| |
| @Override |
| public boolean isFalse() { |
| return false; |
| } |
| |
| @Override |
| public String toString() { |
| return "true"; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return (obj instanceof IAlgebricksConstantValue) && ((IAlgebricksConstantValue) obj).isTrue(); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Boolean.TRUE.hashCode(); |
| } |
| }); |
| public static final ConstantExpression FALSE = new ConstantExpression(new IAlgebricksConstantValue() { |
| |
| @Override |
| public boolean isTrue() { |
| return false; |
| } |
| |
| @Override |
| public boolean isMissing() { |
| return false; |
| } |
| |
| @Override |
| public boolean isNull() { |
| return false; |
| } |
| |
| @Override |
| public boolean isFalse() { |
| return true; |
| } |
| |
| @Override |
| public String toString() { |
| return "false"; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return (obj instanceof IAlgebricksConstantValue) && ((IAlgebricksConstantValue) obj).isFalse(); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Boolean.FALSE.hashCode(); |
| } |
| }); |
| public static final ConstantExpression NULL = new ConstantExpression(new IAlgebricksConstantValue() { |
| |
| @Override |
| public boolean isTrue() { |
| return false; |
| } |
| |
| @Override |
| public boolean isMissing() { |
| return false; |
| } |
| |
| @Override |
| public boolean isNull() { |
| return true; |
| } |
| |
| @Override |
| public boolean isFalse() { |
| return false; |
| } |
| |
| @Override |
| public String toString() { |
| return "NULL"; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return (obj instanceof IAlgebricksConstantValue) && ((IAlgebricksConstantValue) obj).isNull(); |
| } |
| |
| @Override |
| public int hashCode() { |
| return 0; |
| } |
| }); |
| public static final ConstantExpression MISSING = new ConstantExpression(new IAlgebricksConstantValue() { |
| |
| @Override |
| public boolean isTrue() { |
| return false; |
| } |
| |
| @Override |
| public boolean isMissing() { |
| return true; |
| } |
| |
| @Override |
| public boolean isNull() { |
| return false; |
| } |
| |
| @Override |
| public boolean isFalse() { |
| return false; |
| } |
| |
| @Override |
| public String toString() { |
| return "MISSING"; |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| return (obj instanceof IAlgebricksConstantValue) && ((IAlgebricksConstantValue) obj).isMissing(); |
| } |
| |
| @Override |
| public int hashCode() { |
| return 0; |
| } |
| }); |
| |
| public ConstantExpression(IAlgebricksConstantValue value) { |
| this.value = value; |
| } |
| |
| public IAlgebricksConstantValue getValue() { |
| return value; |
| } |
| |
| @Override |
| public LogicalExpressionTag getExpressionTag() { |
| return LogicalExpressionTag.CONSTANT; |
| } |
| |
| @Override |
| public String toString() { |
| return value.toString(); |
| } |
| |
| @Override |
| public void getUsedVariables(Collection<LogicalVariable> vars) { |
| // do nothing |
| } |
| |
| @Override |
| public void substituteVar(LogicalVariable v1, LogicalVariable v2) { |
| // do nothing |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (!(obj instanceof ConstantExpression)) { |
| return false; |
| } else { |
| return value.equals(((ConstantExpression) obj).getValue()); |
| } |
| } |
| |
| @Override |
| public int hashCode() { |
| return value.hashCode(); |
| } |
| |
| @Override |
| public <R, T> R accept(ILogicalExpressionVisitor<R, T> visitor, T arg) throws AlgebricksException { |
| return visitor.visitConstantExpression(this, arg); |
| } |
| |
| @Override |
| public AbstractLogicalExpression cloneExpression() { |
| ConstantExpression c = new ConstantExpression(value); |
| c.setSourceLocation(sourceLoc); |
| return c; |
| } |
| |
| @Override |
| public boolean splitIntoConjuncts(List<Mutable<ILogicalExpression>> conjs) { |
| return false; |
| } |
| } |