Overloading IO functions in step; POC derivation tree generation

1 files changed, 18 insertions, 2 deletions

diff --git a/Smurf.dcl b/Smurf.dcl
index 7d75a6d..25ea30b 100644
--- a/Smurf.dcl
+++ b/Smurf.dcl
@@ -24,6 +24,15 @@ from Data.Maybe import ::Maybe
            , store :: Store
            }
 
+:: IO io = IO (io -> .(String, io)) (String io -> io)
+
+:: ListIO = { input  :: [String]
+            , output :: [String]
+            }
+
+:: Transition = (-->) infix 1 (Program, [String], State) ([String], [String], State)
+:: DerivationTree :== [Transition]
+
 derive gEq Stm
 
 instance == Stm
@@ -34,6 +43,13 @@ instance fromChar Stm
 instance zero State
 instance toString State
 
-step :: !Program State !*File -> *(Maybe (!Program, State), *File)
-run :: !Program State *File -> *(Maybe State, *File)
+instance zero ListIO
+
+instance toString Transition
+instance toString DerivationTree
+
+step :: !Program State u:io u:(IO u:io) -> u:(Maybe (!Program, State), u:io)
+run :: !Program State io (IO io) -> (Maybe State, io)
 
+listIO :: IO ListIO
+tree :: !Program !State !ListIO (IO ListIO) -> Maybe DerivationTree