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
gtkTextIterSetLineIndex
if you have a byte index rather than
a character offset.gtkTextIterSetLineOffset(object, char.on.line)
object
char.on.line
iter
's current line