001/* 002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others. 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 * Contributors: 017 * Nuxeo - initial API and implementation 018 * 019 * $Id$ 020 */ 021 022package org.nuxeo.ecm.core.query.sql.model; 023 024import org.nuxeo.ecm.core.query.sql.NXQL; 025 026/** 027 * An infix expression. 028 * 029 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a> 030 */ 031public class Expression implements Operand { 032 033 private static final long serialVersionUID = 6007989243273673300L; 034 035 public final Operator operator; 036 037 public final Operand lvalue; 038 039 public final Operand rvalue; 040 041 /** Arbitrary info associated to the expression. */ 042 public Object info; 043 044 public Expression(Operand lvalue, Operator operator, Operand rvalue) { 045 this.lvalue = lvalue; 046 this.rvalue = rvalue; 047 this.operator = operator; 048 } 049 050 @Override 051 public void accept(IVisitor visitor) { 052 visitor.visitExpression(this); 053 } 054 055 /** 056 * Is the unary operator pretty-printed after the operand? 057 */ 058 public boolean isSuffix() { 059 return operator == Operator.ISNULL || operator == Operator.ISNOTNULL; 060 } 061 062 public void setInfo(Object info) { 063 this.info = info; 064 } 065 066 public Object getInfo() { 067 return info; 068 } 069 070 @Override 071 public String toString() { 072 if (rvalue == null) { 073 if (isSuffix()) { 074 return lvalue.toString() + ' ' + operator.toString(); 075 } else { 076 return operator.toString() + ' ' + lvalue.toString(); 077 } 078 } else { 079 return lvalue.toString() + ' ' + operator.toString() + ' ' + rvalue.toString(); 080 } 081 } 082 083 @Override 084 public boolean equals(Object obj) { 085 if (obj == this) { 086 return true; 087 } 088 if (obj instanceof Expression) { 089 Expression e = (Expression) obj; 090 if (operator.id != e.operator.id) { 091 return false; 092 } 093 if (!lvalue.equals(e.lvalue)) { 094 return false; 095 } 096 if (rvalue != null) { 097 if (!rvalue.equals(e.rvalue)) { 098 return false; 099 } 100 } else if (e.rvalue != null) { 101 return false; 102 } 103 return true; 104 } 105 return false; 106 } 107 108 @Override 109 public int hashCode() { 110 int result = 17; 111 result = 37 * result + operator.hashCode(); 112 result = 37 * result + (lvalue == null ? 0 : lvalue.hashCode()); 113 result = 37 * result + (rvalue == null ? 0 : rvalue.hashCode()); 114 return result; 115 } 116 117 public boolean isPathExpression() { 118 return (lvalue instanceof Reference) && NXQL.ECM_PATH.equals(((Reference) lvalue).name); 119 } 120 121}