问题
Since non tail recursive recursion calls use stack frames like Java does, I'd be weary to do any recursion that, let's say goes beyond 1,000 times. I would be thus weary to use it for most of things.
Do people actually use non tail recursive recursion in Scala? If so, what are the criteria I can use to determine if it can be non tail recursive?
Also, are there plans to remove this memory restriction in future versions of Scala?
回答1:
In the situation where you cannot use single tail recursion, for example because you need to alternative between two functions, a mechanism called trampolining has been described.
A more recent and thorough discussion of this topic can be found in Rúnar Bjarnason's paper Stackless Scala With Free Monads.
Personally, I would go the easy route and revert to imperative style if you really have this situation with >1K depths, e.g. use a mutable collection builder.
来源：https://stackoverflow.com/questions/24630692/how-usable-is-non-tail-recursive-recursion-in-scala