implementation module pprint

import Control.Applicative
import Control.Monad => qualified join
import Control.Monad.Reader
import Control.Monad.Identity
import Data.Func
import Data.Functor
import Data.List
import Text
import StdEnv

import test

:: DSL | PPrintVar String

pprint :: DSL -> String
pprint d = concat $ runReader (print d) ["x" +++ toString i\\i<-[0..]]

print :: DSL -> Reader [String] [String]
print (Lit i) = pure $ pure $ toString i
print (PPrintVar s) = pure $ pure s
print (Var def) = asks hd >>= \v->
	let (i In d) = def (PPrintVar v)
	in local tl $ ((++) ["var ",v,"=",toString i," in\n"]) <$> print d
print (a +. b) = liftA2 (\as bs->as++["+":bs]) (print a) (print b)