Yeah

choice

, will treat each Arb passed as a Gen, and call generate on a random one - which always returns the edgecases first and joins to the rest of the arb values. The edgecases of the individual arbs are not available in the returned

Arb.edgecases

- you just get an empty list, so that why I thought it makes sense for it to return Gen<A>, but see the value in something like the above which preserves the individual edgecases and values, although its similarity to choice would be confusing.