:sig
StringList regex_split(String pattern, String subject)
StringList regex_split(String pattern, String subject, String flags)

:params
pattern : PCRE2 regular expression pattern used as the separator
subject : string to split
flags : optional regex flags
return value : a list of string parts

:see
>regex
regex_match
regex_search
regex_search_all
regex_replace
split
join
StringList

:content
Splits `subject` wherever `pattern` matches.

Example:

```uce
StringList tags = regex_split("\\s*,\\s*", "uce, components, markdown");
print(join(tags, "\n"));
```

This is the pattern-aware companion to `split()`.

Behavior notes:

- Separators are removed from the returned list.
- Empty fields are preserved.
- If the pattern does not match, the result contains the original subject as a single item.
- Zero-length separators are handled safely to avoid infinite loops.