Try Ruby is a interactive shell that quickly and whimsically teaches the Ruby programming language. Originally _why's idea, it has been recreated from the ground up by Rubyists who have a passion for Ruby and for teaching their fellow (wo)man how to program.
There are some links to some methods for instance in level 8:
same goes for match, find_all etc.
I would open pull request, however I don't find the definitions of those texts. Thanks and kind regards.