@Override
    public Object parse(SourceData sourceData, int rowIndex, Context context) {
        Object stringObject = stringParser.parse(sourceData, rowIndex, context);
        if (stringObject == null) {
            return false;
        }
        String string = OperatorTools.parseString(stringObject).toLowerCase();
        if (string.isEmpty()) {
            return false;
        }
        return string.matches("(\\s)*([+-])?(([0-9]*\\.)?([0-9]+)|([0-9]+)(\\.[0-9]*)?)([eE][\\+-]?[0-9]+)?(\\s)*");
    }
IsDecimalFunction  ->  is_decimal(string)
description:
- Return true if string can be parsed to a valid numeric.
- Return false otherwise (Including cases where string is null and '').
inlong-sdk/transform-sdk/src/main/java/org/apache/inlong/sdk/transform/process/function/string/IsDecimalFunction.java