Matcher#namedGroups() returns only first matching subsequence

[wasiek]

given:

    Pattern pattern = Pattern.compile("(?<digit>\\d)(\\w)");
    Matcher matcher = pattern.matcher("2foo3bar4");

when

    matcher.namedGroups();

then
Only the first group is being found due to reseting of matcher.

[tony19]

Thanks for the report.

To me, the main issue is that the return type of namedGroups() can only hold one value per group. Even if the function looped through to collect matches, it would only hold the last value.

I think the fix would require changing the return type to support multiple values per group (e.g., Map<String, List<String>>).

[wasiek]

Actually in my case named groups hold information about one object so i need something like List<Map<String, String>>. I've already made a method returning List of Maps but couln't make a pull request.

[tony19]

I'm not sure I follow. I assume your list entry would be a map of group name to group value, which seems inefficient compared to a map of group name to multiple group values. Can you clarify how your solution is better?

[wasiek]

This is a small example for something that i need.

Pattern pattern = Pattern.compile("(?<dayOfYear>\\d+).(?<dayName>\\w+)");
Matcher matcher = pattern.matcher("1 Sunday foo bar 2 Monday foo bar 3 Tuesday foo bar 4 Wednesday foo bar 5 Thursday foo bar 6 Friday foo bar  7 Saturday foo bar 8 Sunday foo bar 9 Monday foo bar 10 Tuesday foo bar ");

In my pattern dayOfYear has to go in pair with dayName. What i want to get is:

[
    {"dayOfYear": "1", "dayName": "Sunday"},
    {"dayOfYear": "2", "dayName": "Monday"},
    ...
]

[tony19]

Ok, I see. Try the updated PR.

[tony19]

The fix is released in 0.2.5.