{-# LANGUAGE OverloadedStrings #-}

module Funcons.Core.Abstractions.Thunk where

import Funcons.EDSL
import Funcons.Types

library = libFromList [
        ("thunk", NonStrictFuncon stepThunk) 
    ,   ("thunks", StrictFuncon stepThunks)
    ]

thunk_ :: [Funcons] -> Funcons
thunk_ fargs = applyFuncon "thunk" fargs
stepThunk [f] = rewriteTo $ FValue $ Thunk f
stepThunk fs = sortErr (applyFuncon "thunk" fs) "thunk not applied to a single funcon"

stepThunks [ComputationType ct] = rewriteTo $ type_ $ Thunks ct
stepThunks vs = sortErr (applyFuncon "thunks" (fvalues vs)) 
                    "thunks not applied to computation-type"