+ if (!@add) {
+ # pure removal
+ print join '',
+ '<div class="chunk_block rem">',
+ '<div class="old">',
+ @rem,
+ '</div>',
+ '</div>';
+ } elsif (!@rem) {
+ # pure addition
+ print join '',
+ '<div class="chunk_block add">',
+ '<div class="new">',
+ @add,
+ '</div>',
+ '</div>';
+ } else {
+ # assume that it is change
+ print join '',
+ '<div class="chunk_block chg">',
+ '<div class="old">',
+ @rem,
+ '</div>',
+ '<div class="new">',
+ @add,
+ '</div>',
+ '</div>';
+ }