Simple implementation of Apriori algorithm in R I am preparing a lecture on data mining algorithms in R and I want to demonstrate the famous Apriori algorithm in it.

My question
Could anybody point me to a simple implementation of this algorithm in R?

(I am not looking for a package, e.g. arules, but for comprehensible source code of an implementation from scratch. It also does not help to look at the source code of arules: It just calls a C implementation of the algorithm!)
I found an implementation here: Learning Data Mining with R by Bater Makhabel

The source code can be downloaded here: https://www.packtpub.com/big-data-and-business-intelligence/learning-data-mining-r