[Haskell-cafe] Is there a way to find out the type inferred for a local function inside another function? :)

[Evan Laforge]

>> I would not write large local functions at all. I would leave them
>> top-level but do not export them. This also allows to test them from GHCi.
>
> The downside to this is when you want to use the worker/wrapper transform in
> order to capture some local variables for a recursive function, instead of
> passing them through the recursion.

I do this a lot too, but it doesn't mean you have to have large
functions.  The type of the worker is usually pretty trivially derived
from the type of wrapper, e.g.

wrapper :: A -> B -> C -> D
wrapper a b = go 0
  where go n c = ....

I've had a couple of cases with large functions with large numbers of
parameters that have a complicated recursion pattern and those are
indeed hard to factor into top level functions because each internal
definition uses a random assortment of variables (not necessarily
worker/wrapper either).  I suppose a refactoring editor could pull
inner definitions up to the top level and push them back down, but
hopefully those hairball functions are not common.