Gen.list is not stack safe

[charleso]

We're only using a call-by-need Identity, which is lazy but not stack-safe. That means, among other things, that generating large lists will never work. We should use a stack-safe traverse instead.

https://github.com/scalaz/scalaz/blob/v7.1.5/core/src/main/scala/scalaz/Traverse.scala#L80

[steinybot]

This also means that it blows up for Gen.string with a length of around 2680 with a default stack size of 1M.

[charleso]

This also means that it blows up for Gen.string with a length of around 2680 with a default stack size of 1M.

Yeah I'm sorry. :( In theory it shouldn't be that hard to fix, but I was in a rush last time I tried and got lost in the types.

[pjan]

Running into this as well for Byte Arrays of some length

java.lang.StackOverflowError
  at hedgehog.core.GenT.$anonfun$mapTree$1(GenT.scala:20)
  at hedgehog.core.GenT.$anonfun$flatMap$1(GenT.scala:15)
  at hedgehog.core.GenImplicits2$$anon$2.$anonfun$ap$1(GenT.scala:146)
  at hedgehog.core.GenImplicits2$$anon$2.$anonfun$ap$1(GenT.scala:145)
  at hedgehog.core.GenImplicits2$$anon$2.$anonfun$ap$1(GenT.scala:146)
  at hedgehog.core.GenImplicits2$$anon$2.$anonfun$ap$1(GenT.scala:146)
  ...

Spent some time creating tailRecM's for the different Monads (still need PropertyT and Tree), but seems there's more work to do, and mine is limited. Happy to collaborate with others though, if people are keen.