Gtk.TextView.prototype.backward_display_line_start

function backward_display_line_start(iter:Gtk.TextIter):Boolean {
    // Gjs wrapper for gtk_text_view_backward_display_line_start()
}

Moves the given iter backward to the next display line start. A display line is different from a paragraph. Paragraphs are separated by newlines or other paragraph separator characters. Display lines are created by line-wrapping a paragraph. If wrapping is turned off, display lines and paragraphs will be the same. Display lines are divided differently for each view, since they depend on the view's width; paragraphs are the same in all views, since they depend on the contents of the Gtk.TextBuffer.