| /* ==================================================================== |
| 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.poi.ss.formula.functions; |
| |
| import org.apache.poi.ss.formula.eval.BlankEval; |
| import org.apache.poi.ss.formula.eval.ErrorEval; |
| import org.apache.poi.ss.formula.eval.MissingArgEval; |
| import org.apache.poi.ss.formula.eval.ValueEval; |
| |
| /** |
| * Common interface for all implementations of Excel built-in functions. |
| * |
| * @author Amol S. Deshmukh < amolweb at ya hoo dot com > |
| */ |
| public interface Function { |
| |
| /** |
| * @param args the evaluated function arguments. Empty values are represented with |
| * {@link BlankEval} or {@link MissingArgEval}, never <code>null</code>. |
| * @param srcRowIndex row index of the cell containing the formula under evaluation |
| * @param srcColumnIndex column index of the cell containing the formula under evaluation |
| * @return The evaluated result, possibly an {@link ErrorEval}, never <code>null</code>. |
| * <b>Note</b> - Excel uses the error code <i>#NUM!</i> instead of IEEE <i>NaN</i>, so when |
| * numeric functions evaluate to {@link Double#NaN} be sure to translate the result to {@link |
| * ErrorEval#NUM_ERROR}. |
| */ |
| ValueEval evaluate(ValueEval[] args, int srcRowIndex, int srcColumnIndex); |
| } |