Positive lookbehind followed by comma separated list

Question

I'm looking to see if there is a way to get a match group for each of a comma separated list after a positive lookbehind.

For example

#summertime swimming, running, tanning

Regex (so far)

(?<=#summertime\s)(.+)

Returns

["swimming, running, tanning"]

Desired Results

["swimming", "running", "tanning"]

Answer 1

In php you could do this through PCRE verbs (*SKIP)(*F),

(?:^(?:(?!#summertime).)*$|^.*?#summertime)(*SKIP)(*F)|\w+

DEMO

Answer 2

The classical way to solve this in PCRE/perl is to use \K escape sequence and the \G anchor:

(?:                 # non-capturing group
   \#summertime\b   # match #summertime
   |                # or
   \G(?<!^),        # a comma not at the beginning of string and match it only if it's after the last match
)                   # closing the non-capturing group
\s*                 # some optional whitespaces
\K                  # forget what we matched so far
[^\s,]+             # match anything that's not a whitespace nor a comma one or more times

Some notes on the regex:

• I used the x modifier for white spacing mode.
• You might need to use the g modifier to match all depending on the language. In php you will need to use preg_match_all().
• I escaped the hashtag in #summertime because the hashtag is meant for comments in white spacing mode.
• \G(?<!^) is a classical way of matching from the last point and not from the beginning of string/line. You might also see it in this form \G(?!^) or (?!^)\G. Remember, it's all zero-width.
• \K is awesome.
• I used [^\s,]+ but you might as well use \w+ or what ever suits your needs.
• A bit late but you might as well use your own solution and then split by \s*,\s*

Online demo