136   Line_ptr lp_new;  in line_ptr_decrement()  local
140       lp_new.i = lp->i;  in line_ptr_decrement()
141       lp_new.ptr = lp->ptr - 1;  in line_ptr_decrement()
146       lp_new.i = lp->i - 1;  in line_ptr_decrement()
147       lp_new.ptr = ONE_PAST_END (x, lp->i - 1) - 1;  in line_ptr_decrement()
149   return lp_new;  in line_ptr_decrement()
155   Line_ptr lp_new;  in line_ptr_increment()  local
160       lp_new.i = lp->i;  in line_ptr_increment()
161       lp_new.ptr = lp->ptr + 1;  in line_ptr_increment()
166       lp_new.i = lp->i + 1;  in line_ptr_increment()
167       lp_new.ptr = x->p[lp->i + 1].start;  in line_ptr_increment()
169   return lp_new;  in line_ptr_increment()