feat(haskell): Interaction Tree IO

oops, now we have purely modelled IO 🤷

src/Main.hs

@@ -5,6 +5,7 @@ import System.Exit (die)
 import Server (runServerWithPath)
 import Eval (evalTricu, evalTricuWithStore, mainResult, result)
 import FileEval (evaluateFileWithContext, evaluateFileWithStore, compileFile)
+import IODriver (IOPermissions(..), checkIOSentinel, runIO)
 import Parser (parseTricu)
 import REPL (repl)
 import Research (T, EvaluatedForm(..), Env, formatT, exportDag)
@@ -32,10 +33,13 @@ import System.Environment (lookupEnv)
 data TricuArgs
   = Repl
   | Eval
-      { evalFiles   :: [FilePath]
-      , evalFormat  :: EvaluatedForm
-      , evalOutput  :: FilePath
-      , evalDb      :: Maybe FilePath
+      { evalFiles      :: [FilePath]
+      , evalFormat     :: EvaluatedForm
+      , evalOutput     :: FilePath
+      , evalDb         :: Maybe FilePath
+      , evalIo         :: Bool
+      , evalAllowRead  :: [FilePath]
+      , evalAllowWrite :: [FilePath]
       }
   | ArboricxCompile
       { compileInput   :: FilePath
@@ -98,6 +102,20 @@ evalParser = Eval
      <> metavar "PATH"
      <> help "Content store database path"
       ))
+  <*> switch
+      ( long "io"
+     <> help "Interpret the result as an IO action tree and execute it"
+      )
+  <*> many (option str
+      ( long "allow-read"
+     <> metavar "PATH"
+     <> help "Allow reading from PATH prefix (repeatable)"
+      ))
+  <*> many (option str
+      ( long "allow-write"
+     <> metavar "PATH"
+     <> help "Allow writing to PATH prefix (repeatable)"
+      ))
 
 compileParser :: Parser TricuArgs
 compileParser = ArboricxCompile
@@ -273,10 +291,18 @@ runEval opts = do
     _  -> do
       finalEnv <- foldM (evaluateFileWithStore mconn) Map.empty files
       return $ mainResult finalEnv
+  finalT <- if evalIo opts
+    then case checkIOSentinel resultT of
+      Right (1, action) -> do
+        let perms = IOPermissions (evalAllowRead opts) (evalAllowWrite opts)
+        runIO perms action
+      Right (v, _) -> die $ "Unsupported IO ABI version: " ++ show v
+      Left err -> die $ "IO mode requested but " ++ err
+    else return resultT
   case mconn of
     Just conn -> close conn
     Nothing   -> return ()
-  writeOutput out (formatT form resultT)
+  writeOutput out (formatT form finalT)
 
 runCompile :: TricuArgs -> IO ()
 runCompile opts = do