+sub print_sidebyside_diff_chunk {
+ my @chunk = @_;
+ my (@ctx, @rem, @add);
+
+ return unless @chunk;
+
+ # incomplete last line might be among removed or added lines,
+ # or both, or among context lines: find which
+ for (my $i = 1; $i < @chunk; $i++) {
+ if ($chunk[$i][0] eq 'incomplete') {
+ $chunk[$i][0] = $chunk[$i-1][0];
+ }
+ }
+
+ # guardian
+ push @chunk, ["", ""];
+
+ foreach my $line_info (@chunk) {
+ my ($class, $line) = @$line_info;
+
+ # print chunk headers
+ if ($class && $class eq 'chunk_header') {
+ print $line;
+ next;
+ }
+
+ ## print from accumulator when type of class of lines change
+ # empty contents block on start rem/add block, or end of chunk
+ if (@ctx && (!$class || $class eq 'rem' || $class eq 'add')) {
+ print join '',
+ '<div class="chunk_block">',
+ '<div class="old">',
+ @ctx,
+ '</div>',
+ '<div class="new">',
+ @ctx,
+ '</div>',
+ '</div>';
+ @ctx = ();
+ }
+ # empty add/rem block on start context block, or end of chunk
+ if ((@rem || @add) && (!$class || $class eq 'ctx')) {
+ print join '',
+ '<div class="chunk_block">',
+ '<div class="old">',
+ @rem,
+ '</div>',
+ '<div class="new">',
+ @add,
+ '</div>',
+ '</div>';
+ @rem = @add = ();
+ }
+
+ ## adding lines to accumulator
+ # guardian value
+ last unless $line;
+ # rem, add or change
+ if ($class eq 'rem') {
+ push @rem, $line;
+ } elsif ($class eq 'add') {
+ push @add, $line;
+ }
+ # context line
+ if ($class eq 'ctx') {
+ push @ctx, $line;
+ }
+ }
+}
+