setLineOffset
Moves @iter within a line, to a new character (not byte) offset.
The given character offset must be less than or equal to the number of characters in the line; if equal, @iter moves to the start of the next line. See method@Gtk.TextIter.set_line_index if you have a byte index rather than a character offset.
Parameters
charOnLine
a character offset relative to the start of @iter’s current line