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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
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http://www.apache.org/licenses/LICENSE-2.0
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distributed under the License is distributed on an "AS IS" BASIS,
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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);
}