A line is simply a string, possibly empty, that does not contain a newline character. As the name suggests, usually such strings are obtained by reading a file line by line.

parse_string s splits s on newline characters, returning the resulting list of lines. If the final line ended with a newline, the last string of the list is empty.

rightmost s returns a pair whose right member is the longest suffix v of s that represents a line, while the possible remainder of s (minus the newline character) is represented in the left member. More formally, if v = s then the left member of the pair is None; otherwise it is Some u where s = u ^ "\n" ^ v.

Return the given string without checking that it is a line. Useful for efficiency reasons if you're certain the given string is a line.

• raises [Invalid_arg

  _] if sep = '\n'