| /* |
| * 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.asterix.lang.sqlpp.util; |
| |
| import org.apache.asterix.common.exceptions.CompilationException; |
| import org.apache.asterix.lang.common.base.Expression; |
| import org.apache.asterix.lang.common.base.Expression.Kind; |
| import org.apache.asterix.lang.common.expression.FieldAccessor; |
| import org.apache.asterix.lang.common.expression.VariableExpr; |
| import org.apache.asterix.lang.common.struct.VarIdentifier; |
| import org.apache.asterix.lang.sqlpp.parser.ParseException; |
| import org.apache.asterix.lang.sqlpp.parser.SqlppParseException; |
| import org.apache.hyracks.util.LogRedactionUtil; |
| import org.apache.logging.log4j.LogManager; |
| import org.apache.logging.log4j.Logger; |
| |
| public class ExpressionToVariableUtil { |
| |
| private static final Logger LOGGER = LogManager.getLogger(); |
| |
| private ExpressionToVariableUtil() { |
| } |
| |
| private static String getGeneratedIdentifier(Expression expr) throws ParseException { |
| if (expr.getKind() == Kind.VARIABLE_EXPRESSION) { |
| VariableExpr bindingVarExpr = (VariableExpr) expr; |
| VarIdentifier var = bindingVarExpr.getVar(); |
| return SqlppVariableUtil.isExternalVariableIdentifier(var) ? null : var.getValue(); |
| } else if (expr.getKind() == Kind.FIELD_ACCESSOR_EXPRESSION) { |
| FieldAccessor fa = (FieldAccessor) expr; |
| return SqlppVariableUtil.toInternalVariableName(fa.getIdent().getValue()); |
| } else { |
| String exprText; |
| try { |
| exprText = SqlppFormatPrintUtil.toString(expr); |
| } catch (CompilationException e) { |
| LOGGER.error(e.getLocalizedMessage(), e); |
| throw new SqlppParseException(expr.getSourceLocation(), e.getLocalizedMessage()); |
| } |
| throw new SqlppParseException(expr.getSourceLocation(), |
| "Need an alias for the enclosed expression:\n" + LogRedactionUtil.userData(exprText)); |
| } |
| } |
| |
| /** |
| * Generates an identifier according to an expression. |
| * |
| * @param expr |
| * the input expression. |
| * @param raiseError, |
| * if it is not possible to generate an identifier from the input expression, |
| * to raise the error if true, and to return a null if false. |
| * @return the generated identifier. |
| * @throws ParseException |
| */ |
| public static String getGeneratedIdentifier(Expression expr, boolean raiseError) throws ParseException { |
| try { |
| return getGeneratedIdentifier(expr); |
| } catch (ParseException e) { |
| if (raiseError) { |
| throw e; |
| } |
| return null; |
| } |
| } |
| |
| /** |
| * Generates a variable according to an expression. |
| * |
| * @param expr |
| * the input expression. |
| * @param raiseError, |
| * if it is not possible to generate a variable from the input expression, |
| * to raise the error if true, and to return a null if false. |
| * @return the generated variable. |
| * @throws ParseException |
| */ |
| public static VariableExpr getGeneratedVariable(Expression expr, boolean raiseError) throws ParseException { |
| try { |
| String varName = getGeneratedIdentifier(expr); |
| VarIdentifier var = new VarIdentifier(varName); |
| VariableExpr varExpr = new VariableExpr(var); |
| varExpr.setSourceLocation(expr.getSourceLocation()); |
| return varExpr; |
| } catch (ParseException e) { |
| if (raiseError) { |
| throw e; |
| } |
| return null; |
| } |
| } |
| |
| } |