int cellType = cell.getCellType();
switch (cellType) {
case Cell.CELL_TYPE_NUMERIC:
return new NumberEval(cell.getNumericCellValue());
case Cell.CELL_TYPE_STRING:
return new StringEval(cell.getStringCellValue());
case Cell.CELL_TYPE_BOOLEAN:
return BoolEval.valueOf(cell.getBooleanCellValue());
case Cell.CELL_TYPE_BLANK:
return BlankEval.instance;
case Cell.CELL_TYPE_ERROR: