gtk:text-view-scroll-to-mark (view mark &key margin xalign yalign)

view -- a gtk:text-view widget
mark -- a gtk:text-mark object
margin -- a number coerced to a double float for the margin as a [0.0, 0.5) fraction of screen size
xalign -- a number coerced to a double float for the horizontal alignment of the mark within visible area
yalign -- a number coerced to a double float for the vertical alignment of the mark within visible area

Scrolls the text view so that the mark is on the screen in the position indicated by the xalign and yalign arguments. An alignment of 0.0 indicates left or top, 1.0 indicates right or bottom, 0.5 means center. If you do not pass a value for the xalign and yalign arguments, the text scrolls the minimal distance to get the mark onscreen, possibly not scrolling at all. The effective screen for purposes of this function is reduced by a margin of size margin.