Returns the slice of source up to the first occurrence of delim,
and fast-forwards source to the point after delim.
If delim is not found, the behavior depends on orUntilEnd:
- If orUntilEnd is false (default), it returns null
and leaves source unchanged.
- If orUntilEnd is true, it returns source,
and then sets source to null.
Returns the slice of source up to the first occurrence of delim, and fast-forwards source to the point after delim. If delim is not found, the behavior depends on orUntilEnd: - If orUntilEnd is false (default), it returns null and leaves source unchanged. - If orUntilEnd is true, it returns source, and then sets source to null.