如何制作regexp我不需要匹配/可选匹配的Ruby？

Question

Im trying to create a regexp that matches parts of some strings. I doesnt have to match everypart, but at least one ( which it always will )

I want: Name and Year and / or Season/Episode.

Lets say I have these strings:

1. i.want.this.as.name.2014.s01e02
2. i still want a this 2010
3. i also want this
4. I still want this.S05E23.720p.HDTV.X264

I would like to get these matches:

1. 
name =  i.want.this.as.name.
year =  2014
seasonepisode =     s01e02
season =    01
episode =   02
2.
name = i still want a this
year = 2010
3.
name = i also want this
4.
name =  I still want this
seasonepisode =     s05e23
season =    05
episode =   23

Right now, i have this regexp:

(?<name>.*)(?<year>\d{4})(\s|\.|\z)*(?<seasonepisode>s(?<season>\d{1,2})e(?<episode>\d{1,2}))*

But I only get the desired result on the first string. I guess that is because there are no matches for the full regexp in the string 2, 3 or 4.

Here you can try the regexp: http://rubular.com/r/1ypseJ7c6I

So my question is, how do I tell the regexp that i dont require matches on everything, just something? :-) I have tried added asterix to the opitonal.

5€ donation to a project / charity of your choice for the correct answer :-)

Answer 1

This might work: http://rubular.com/r/4qYuzGGqaB . Using /ix options, the latter for readability.

^
(?<nm>.+?)        # Name: at least one character, non-greedy.
(?<yr>\d{4})?     # Year, optional.
(?:               # Post-year stuff, non-captured.
  [\s\.]
  s(?<se>\d\d?)   # Season.
  e(?<ep>\d\d?)   # Episode.
  (?<rest>.*)     # The rest, optional.
)?                # Post-year stuff is optional.
$                 # Must consume full line.

A couple of notes:

• The non-greediness of the name-group is important. Otherwise, it will happily consume the entire line (everything else is optional).

• Requiring a full line match is also important. Otherwise, the pattern will happily match only the first letter of the line (the name is non-greedy, everything else is optional).