Hi, I recently asked about what interfaces to implement for a new data type. Following the rule that the last 10% of work take the second 90% of time, some other questions have come up. If anyone wants to look at the code in question: http://www.chr-breitkopf.de/comp/IntervalMap Some time ago, I was looking for a data structure to search in sets of possibly overlapping intervals, and found only Data.SegmentTree, which did not fit my needs (nice term for "I did not understand the type signatures"). So I started to roll my own IntervalMap implementation. But yesterday I used Hayoo instead of Hoogle for the first time, and found Data.IntervalMap.FingerTree. This has an Interface that I _do_ understand, and, while slightly different from my aims (depite the name, it seems more like a multi-map and does not offer lookup of specific keys), it raises some tasks/questions: Tasks: Benchmark against my implementation, and maybe scrap own if it performs worse. And questions: 1. Why doesn't Hoogle find this? 2. Module name space pollution I would have been so bold to name my module Data.IntervalMap. Now, since even Ross Patterson uses a submodule name instead, what is the accepted practice? If I decide to release my class after all, what should be the name? Data.IntervalMap.RedBlackTree ? Or even Data.IntervalMap.MyDomaindNameOrSomething. An I even have a module Data.IntervalMap.Interval, so if Ross had decided to put his Interval type into a separate module, even FingerTree vs RedBlackTree would not have prevented a name clash. 3. Are there more wothwile operations on this data structure? Data.IntervalMap.FingerTree has 'dominators', which I missed. A function to extract the interval with the largest endpoint might be useful, too. Any more ideas? TIA, Chris