Is it possible to use Agda as a library?

Question

Instead of using Agda on a filesystem (with EMACS, terminal, etc.), is it possible to use it directly from Haskell, as a library? For example:

-- UsingAgda.hs
import Agda

-- Prints the type of a term on some Agda code
main :: IO ()
main = typeOf "true" agdaCode where

  agdaCode :: String
  agdaCode = unlines
    ["module Hello where   "
    ,"                     "
    ,"data Bool : Set where"
    ,"  true  : Bool       "
    ,"  false : Bool       "]

The code above would output Bool, because true : Bool on that Agda code.

Answer 1

Yes, it is possible. Agda was designed as a Haskell library plus a main module.

You can see a couple of small examples here. As a bigger example, I wrote Apia (shameless plug), which uses Agda as a library.

Please keep in mind that the current Agda description says:

Note that the Agda package does not follow the package versioning policy, because it is not intended to be used by third-party packages.

Of course, it could change.