[New module system] Instantiate functor while importing

[rybla]

#1363 feature request

I would be extremely convenient to be able to instantiate a functor while importing it. The following example demonstrates how a module App can import a functor Lib by instantiating it with I_inst an instance of the interface I that Lib is parametrized by.

module interface I where
a : *
x : a

module I_inst = I where
a = [8]
x = 1

module Lib where
import interface I

module App where
import Lib { I = I_inst }

Additionally, the following example demonstrates how a module App can import a functor Lib that is parametrized by an anonymous module (encoded by the parameter syntax) by immediately instantiating its parameters right after the import statement using a where clause.

module Lib where
parameter
  a : *
  x : a

module App where
import Lib where
  a = [8]
  x = 1

[m-yac]

Fixed in #1363.