Hi. I was reading with interest the blog post on Traversal-enabled objects ( http://www.humane-assessment.com/blog/traversal-enabled-pharo-objects ) when I noticed the method #deepCollect: referenced. Interestingly, I have a method called #deepCollect: that is use (wtih related methods like #deepDo: and #deepSelect:). I suspect these uses may be compatible, with the traveral versions being more generic. My set of #deep methods allow arbitrary flattening of collections. The #flatCollect: suite in Pharo today flattens objects 1 level; the #deepCollect: flattens the collections as many levels deep as they are nested. I found this to be a really useful ability when I work with PetitParser parsings, which tend give back massively nested Arrays by default. If you are interested, it is published at: http://www.smalltalkhub.com/#!/~cbc/DeepCollection/ . -cbc