Host ABI definition and ergonomics in TC

test/Spec.hs

@@ -2795,4 +2795,65 @@ manifestReadingTests = testGroup "Manifest Reading Tests"
       let env = evalTricu library (parseTricu input)
       toString (result env) @?= Right "left"
       close srcConn
+
+  , testCase "host ABI: constructors expose tag and payload" $ do
+      library <- evaluateFile "./lib/arboricx.tri"
+      let stringInput = "hostString \"hello\""
+          stringEnv = evalTricu library (parseTricu stringInput)
+      result stringEnv @?= pairT (ofNumber 1) (ofString "hello")
+      let tagEnv = evalTricu library (parseTricu "hostValueTag (hostNumber 42)")
+      result tagEnv @?= ofNumber 2
+      let payloadEnv = evalTricu library (parseTricu "hostValuePayload (hostBool true)")
+      result payloadEnv @?= trueT
+
+  , testCase "runArboricxToTree: wraps raw result as hostTree" $ do
+      (srcConn, termHash, originalTerm) <- storeTermInTempDB $ unlines
+        [ "main = t t" ]
+      wireData <- exportBundle srcConn [termHash]
+      let input = "matchResult "
+            ++ "  (code rest : err code rest) "
+            ++ "  (hostValue rest : ok hostValue []) "
+            ++ "  (runArboricxToTree " ++ bytesExpr (map toInteger $ BS.unpack wireData) ++ " [])"
+      library <- evaluateFile "./lib/arboricx.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT (pairT (ofNumber 0) originalTerm) (bytesT [])
+      close srcConn
+
+  , testCase "runArboricxToString: wraps string result as hostString" $ do
+      (srcConn, termHash, _) <- storeTermInTempDB $ unlines
+        [ "main = (x : x)" ]
+      wireData <- exportBundle srcConn [termHash]
+      let input = "matchResult "
+            ++ "  (code rest : err code rest) "
+            ++ "  (hostValue rest : ok hostValue []) "
+            ++ "  (runArboricxToString " ++ bytesExpr (map toInteger $ BS.unpack wireData) ++ " [(\"hello\")])"
+      library <- evaluateFile "./lib/arboricx.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT (pairT (ofNumber 1) (ofString "hello")) (bytesT [])
+      close srcConn
+
+  , testCase "runArboricxToNumber: wraps number result as hostNumber" $ do
+      (srcConn, termHash, _) <- storeTermInTempDB $ unlines
+        [ "main = 42" ]
+      wireData <- exportBundle srcConn [termHash]
+      let input = "matchResult "
+            ++ "  (code rest : err code rest) "
+            ++ "  (hostValue rest : ok hostValue []) "
+            ++ "  (runArboricxToNumber " ++ bytesExpr (map toInteger $ BS.unpack wireData) ++ " [])"
+      library <- evaluateFile "./lib/arboricx.tri"
+      let env = evalTricu library (parseTricu input)
+      result env @?= okT (pairT (ofNumber 2) (ofNumber 42)) (bytesT [])
+      close srcConn
+
+  , testCase "runArboricxToBool: rejects non-bool result" $ do
+      (srcConn, termHash, _) <- storeTermInTempDB $ unlines
+        [ "main = 42" ]
+      wireData <- exportBundle srcConn [termHash]
+      let input = "runArboricxToBool " ++ bytesExpr (map toInteger $ BS.unpack wireData) ++ " []"
+      library <- evaluateFile "./lib/arboricx.tri"
+      let env = evalTricu library (parseTricu input)
+      case result env of
+        Fork falseTag (Fork code _) | falseTag == falseT -> code @?= ofNumber 14
+        actual -> assertFailure $ "expected host codec error, got: " ++ show actual
+      close srcConn
   ]