fix a little problem
fix `each_slice` can't trigger
Merge pull request #116 from mygoare/patch-1

ruby: make each_with_index snippet consistent with the rest of the file.
Merge pull request #117 from mygoare/patch-2

ruby: fix `each_slice` can't trigger
Merge pull request #115 from heytrav/master

perl: use parent in place of base and uncuddle "else" as suggested by the Perl Best Practices book.