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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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package org.apache.poi.hssf.record.formula.functions;
import org.apache.poi.hssf.record.formula.eval.AreaEval;
import org.apache.poi.hssf.record.formula.eval.ErrorEval;
import org.apache.poi.hssf.record.formula.eval.Eval;
import org.apache.poi.hssf.record.formula.eval.EvaluationException;
import org.apache.poi.hssf.record.formula.eval.OperandResolver;
import org.apache.poi.hssf.record.formula.eval.ValueEval;
import org.apache.poi.hssf.record.formula.functions.LookupUtils.ValueVector;
/**
* Implementation of the VLOOKUP() function.<p/>
*
* VLOOKUP finds a row in a lookup table by the first column value and returns the value from another column.<br/>
*
* <b>Syntax</b>:<br/>
* <b>VLOOKUP</b>(<b>lookup_value</b>, <b>table_array</b>, <b>col_index_num</b>, range_lookup)<p/>
*
* <b>lookup_value</b> The value to be found in the first column of the table array.<br/>
* <b>table_array</b> An area reference for the lookup data. <br/>
* <b>col_index_num</b> a 1 based index specifying which column value of the lookup data will be returned.<br/>
* <b>range_lookup</b> If TRUE (default), VLOOKUP finds the largest value less than or equal to
* the lookup_value. If FALSE, only exact matches will be considered<br/>
*
* @author Josh Micich
*/
public final class Vlookup implements Function {
private static final class ColumnVector implements ValueVector {
private final AreaEval _tableArray;
private final int _size;
private final int _columnAbsoluteIndex;
private final int _firstRowAbsoluteIndex;
public ColumnVector(AreaEval tableArray, int columnIndex) {
_columnAbsoluteIndex = tableArray.getFirstColumn() + columnIndex;
if(!tableArray.containsColumn((short)_columnAbsoluteIndex)) {
int lastColIx = tableArray.getLastColumn() - tableArray.getFirstColumn();
throw new IllegalArgumentException("Specified column index (" + columnIndex
+ ") is outside the allowed range (0.." + lastColIx + ")");
}
_tableArray = tableArray;
_size = tableArray.getLastRow() - tableArray.getFirstRow() + 1;
if(_size < 1) {
throw new RuntimeException("bad table array size zero");
}
_firstRowAbsoluteIndex = tableArray.getFirstRow();
}
public ValueEval getItem(int index) {
if(index>_size) {
throw new ArrayIndexOutOfBoundsException("Specified index (" + index
+ ") is outside the allowed range (0.." + (_size-1) + ")");
}
return _tableArray.getValueAt(_firstRowAbsoluteIndex + index, (short)_columnAbsoluteIndex);
}
public int getSize() {
return _size;
}
}
public Eval evaluate(Eval[] args, int srcCellRow, short srcCellCol) {
Eval arg3 = null;
switch(args.length) {
case 4:
arg3 = args[3]; // important: assumed array element is never null
case 3:
break;
default:
// wrong number of arguments
return ErrorEval.VALUE_INVALID;
}
try {
// Evaluation order:
// arg0 lookup_value, arg1 table_array, arg3 range_lookup, find lookup value, arg2 col_index, fetch result
ValueEval lookupValue = OperandResolver.getSingleValue(args[0], srcCellRow, srcCellCol);
AreaEval tableArray = LookupUtils.resolveTableArrayArg(args[1]);
boolean isRangeLookup = LookupUtils.resolveRangeLookupArg(arg3, srcCellRow, srcCellCol);
int rowIndex = LookupUtils.lookupIndexOfValue(lookupValue, new ColumnVector(tableArray, 0), isRangeLookup);
ValueEval veColIndex = OperandResolver.getSingleValue(args[2], srcCellRow, srcCellCol);
int colIndex = LookupUtils.resolveRowOrColIndexArg(veColIndex);
ValueVector resultCol = createResultColumnVector(tableArray, colIndex);
return resultCol.getItem(rowIndex);
} catch (EvaluationException e) {
return e.getErrorEval();
}
}
/**
* Returns one column from an <tt>AreaEval</tt>
*
* @throws EvaluationException (#VALUE!) if colIndex is negative, (#REF!) if colIndex is too high
*/
private ValueVector createResultColumnVector(AreaEval tableArray, int colIndex) throws EvaluationException {
if(colIndex < 0) {
throw EvaluationException.invalidValue();
}
int nCols = tableArray.getLastColumn() - tableArray.getFirstColumn() + 1;
if(colIndex >= nCols) {
throw EvaluationException.invalidRef();
}
return new ColumnVector(tableArray, colIndex);
}
}