Some utility stuff I copy paste between projects:

  - range, clamp, inIvl, enumerate, topK
  - groupBy (array to record), numeric / lexical array sorts
  - seeded rng
  - throttling
  - attachDragListener (like d3's mousedown -> mousemove -> mouseup)
  - Maps / Sets that accept non-primitive keys (ie custom hash)

So basically functions that every *dash variant includes.