Being able to loop over arrays that are the results of function calls

[Frizlab]

Is your feature request related to a problem? Please describe.
I tried to do this:

#for(status in entryStatuses()):
  some stuff
#endfor

Where entryStatuses is a custom leaf tag (which has been tested to work and return an array).

However I got an error: for loops expect single expression, 'name in names'

Describe the solution you'd like
It’d be great to have the array on which we want to loop be able to be any expression, not a simple variable.

Describe alternatives you've considered
I am currently sending the array via the context instead of the custom leaf tag I created.

Additional context
None.

[0xTim]

Closing in favour of vapor/leaf-kit#81