Method bkwd

Astronomy_/src/main/java/util/Stack_Sorter.java:351–363

()

    }

    void bkwd() {
        if (slice != numSlices) {
            if (stack instanceof VirtualStack virtualStack) {
                virtualStack.swapSlices(slice, slice + 1);
            } else {
                stack.addSlice(stack.getSliceLabel(slice), stack.getProcessor(slice), slice + 1);
                stack.deleteSlice(slice);
            }
            imp.setStack(null, stack);
            imp.setSlice(slice + 1);
            imp.updateAndDraw();
        }
    }

    void fwd() {
        if (slice != 1) {