module Paraphrases (mkParaphrases) where

import Operations
import AbsGFC
import GFC
import Look
import CMacros ---- (mkApp, eqStrIdent)
import AbsCompute
import List (nub)

-- paraphrases of GF terms. AR 6/10/1998 -- 24/9/1999 -- 5/7/2000 -- 5/6/2002
-- Copyright (c) Aarne Ranta 1998--99, under GNU General Public License (see GPL)
-- thus inherited from the old GF. Incomplete and inefficient...

mkParaphrases :: CanonGrammar -> Exp -> [Exp]
mkParaphrases st t = [t]
---- mkParaphrases st = nub . map (beta []) . paraphrases (allDefs st)

{- ----
type Definition = (Fun,Trm)

paraphrases :: [Definition] -> Trm -> [Trm]
paraphrases th t =
  t :
  paraImmed th t ++
---  paraMatch th t ++
  case t of
    App c a -> [App d b | d <- paraphrases th c, b <- paraphrases th a]
    Abs x b -> [Abs x d | d <- paraphrases th b]
    c       -> []

paraImmed :: [Definition] -> Trm -> [Trm]
paraImmed defs t = 
  [Cn f | (f, u) <- defs, t == u] ++ --- eqTerm
  case t of
    Cn c -> [u | (f, u) <- defs, eqStrIdent f c]
    _    -> []
-}
{- ---
paraMatch :: [Definition] -> Trm -> [Trm]
paraMatch th@defs t = 
 [mkApp (Cn f) xx | (PC f zz, u) <- defs, 
                    let (fs,sn) = fullApp u, fs == h, length sn == length zz] ++
 case findAMatch defs t of
   Ok (g,b) -> [substTerm [] g b]
   _        -> []
  where 
    (h,xx)    = fullApp t
    fullApp c = case c of 
                  App f a -> (f', a' ++ [a]) where (f',a') = fullApp f
                  c       -> (c,[])

-}