actually print out minor stuff

app/Builtins.hs

@@ -2,11 +2,14 @@ module Builtins where
 
 import Code
 import Control.Monad.IO.Class
+import Control.Monad.Trans.Class
 import Control.Monad.Trans.State.Lazy
 import qualified Data.Map as M
 import Env hiding (PrlgEnv)
+import qualified IR
 import Interpreter (backtrack)
 import qualified Operators as O
+import System.Console.Haskeline
 
 bi = Builtin
 
@@ -17,8 +20,20 @@ hello = do
 
 printLocals :: BuiltinFn
 printLocals = do
+  scope <- gets (gvar . cur)
+  Heap _ heap <- gets (heap . cur)
+  IR.StrTable _ _ itos <- gets strtable
+  flip traverse (M.elems scope) $ \(ref, name) ->
+    lift . outputStrLn $ (itos M.! name) ++ " = " ++ show (heap M.! ref)
   return Nothing
 
+promptRetry :: BuiltinFn
+promptRetry = do
+  x <- lift $ getInputChar "? "
+  case x of
+    Just ';' -> backtrack
+    _ -> return Nothing
+
 addBuiltins :: PrlgEnv ()
 addBuiltins = do
   a1 <- findStruct "a" 1
@@ -34,6 +49,7 @@ addBuiltins = do
   true0 <- findStruct "true" 0
   printlocals0 <- findStruct "print_locals" 0
   debugprint0 <- findStruct "interpreter_state" 0
+  promptretry0 <- findStruct "prompt_retry" 0
   modify $ \s ->
     s
       { defs =
@@ -50,6 +66,8 @@ addBuiltins = do
             , (true0, [[Invoke $ bi (pure Nothing)]])
             , ( debugprint0
               , [[Invoke $ bi (get >>= liftIO . print >> pure Nothing)]])
+            , (printlocals0, [[Invoke $ bi printLocals]])
+            , (promptretry0, [[Invoke $ bi promptRetry]])
             ]
       , ops = [(O.xfy "," 1000), (O.xfx "=" 700)]
       }