public HashMap<String,String> getInputColumnNames() {
    return inputColumnNamesMap;
  }
return rows that meet a specified pattern. Use symbols to specify a list of expressions
to match.
Pattern is used to specify a Path. The results list can contain expressions based on
the input columns and also the matched Path.
<ol>
<li><b>pattern:</b> pattern for the Path. Path is 'dot' separated list of symbols.
Each element is treated as a symbol. Elements that end in '*' or '+' are interpreted with
the usual meaning of zero or more, one or more respectively. For e.g.
"LATE.EARLY*.ONTIMEOREARLY" implies a sequence of flights
where the first occurrence was LATE, followed by zero or more EARLY flights,
followed by a ONTIME or EARLY flight.
<li><b>symbols</b> specify a list of name, expression pairs. For e.g.
'LATE', arrival_delay &gt; 0, 'EARLY', arrival_delay &lt; 0 , 'ONTIME', arrival_delay == 0.
These symbols can be used in the Pattern defined above.
<li><b>resultSelectList</b> specified as a select list.
The expressions in the selectList are evaluated in the context where all the
input columns are available, plus the attribute
"tpath" is available. Path is a collection of rows that represents the matching Path.
</ol>
ql/src/java/org/apache/hadoop/hive/ql/udf/ptf/MatchPath.java