{-# LANGUAGE QuasiQuotes #-}
import Typesafe
import Language.LBNF.Runtime(printTree) -- overloaded pretty-printing function
import Prelude hiding (exp)


-- All variables are meta-variables. 
-- Variables must be declared in the function parameters
-- Boolean and numeric variables are type checked by Haskell.
prg n tmp x = [prog|
f() {
  n = 0;
  x := True ;
  tmp = 0;
  while ( tmp < 10 ) {
    tmp++;
    n = n * n;
  }
}
|]

main = putStr $ printTree $ fresh vars prg where
  vars = (map return ['a'..'z']) ++ ['v' : show n  |n <- [0..]]



class Variable a where
  fromString :: String -> a

instance Variable NVar where
  fromString = NVar . Ident

instance Variable BVar where
  fromString = BVar . Ident


class Fresh a where
  fresh :: [String] -> a -> Prog
  
instance Fresh Prog where
  fresh _ e = e
  
instance (Variable a, Fresh b) => Fresh  (a -> b) where
  fresh (s:ss) g = fresh ss $ g (fromString s)