(cffi:defcstruct css-location
  (bytes :size)
  (chars :size)
  (lines :size)
  (line-bytes :size)
  (line-chars :size))  

bytes

Number of bytes parsed since the beginning.

chars

Number of characters parsed since the beginning.

lines

Number of full lines that have been parsed. If you want to display this as a line number, you need to add 1 to this.

line-bytes

Number of bytes parsed since the last line break.

line-chars

Number of characters parsed since the last line break.

The gtk:css-location structure is used to present a location in a file or other source of data parsed by the CSS engine. The bytes and line-bytes offsets are meant to be used to programmatically match data. The lines and line-chars offsets can be used for printing the location in a file.

Note that the lines parameter starts from 0 and is increased whenever a CSS line break is encountered. CSS defines the C character sequences "\r\n", "\r", "\n" and "\f" as newlines. If your document uses different rules for line breaking, you might want run into problems here.