--
-- Examples for use with LambdaNu
--

imap f xs	    =  begin
                         (new 
			   (\t ->
			     assign t xs >>
			     let loop = deref t >>= \ys ->
			                case ys of 
				          (y:ys') -> out (f y :) >>
					             assign t ys' >>
						     loop
				          [] -> outConst []
                             in loop))

imap' f xs  = newvar      >>= \t ->
              assign t xs >>
              let loop = t ? \ys ->
                         case ys of (z:zs) -> out (f z :) >>
                                              assign t zs >>
                                              loop
                                    []     -> outConst []
             in  loop


ones = 1:ones
					 
test1 = imap (+1) [1,2,3]
test2 = imap (+1) ones

funny x = begin (new (\t -> assign t x >>
                            deref t    >>= \x' ->
                            outConst x'))

funny' x y = begin (new (\t ->
                   (new (\s -> assign t x >>
                               assign s y >>
                               deref t    >>= \x' ->
                               deref s    >>= \y' ->
                               outConst (x',y')))))

double xs = begin
              (new
                (\t -> assign t xs >>
                       let loop = deref t >>= \zs ->
                                  case zs of
                                    (y:ys) -> out (\zs -> y:y:zs) >>
                                              assign t ys         >>
                                              loop
                                    []     -> out (const [])
                       in  loop))


double' xs = begin
              (let loop (y:ys) = out (\zs -> y:y:zs) >> loop ys
                   loop []     = out (const [])
               in  loop xs)


double'' (y:ys) = y : y : double'' ys
double'' []     = []