✨ try-catch

a4/src/APL/InterpPure.hs

@@ -13,4 +13,8 @@ runEval = runEval' envEmpty stateInitial
     runEval' r s (Free (PrintOp p m)) =
       let (ps, res) = runEval' r s m
        in (p : ps, res)
+    runEval' r s (Free (TryCatchOp m l)) =
+      case (runEval' r s m) of
+        (_, Left e) -> runEval' r s l
+        a -> a
     runEval' _ _ (Free (ErrorOp e)) = ([], Left e)

a4/src/APL/Interp_Tests.hs

@@ -65,6 +65,22 @@ pureTests =
       --
       testCase "Div0" $
         eval' (Div (CstInt 7) (CstInt 0))
+          @?= ([], Left "Division by zero"),
+      --
+      testCase "TryCatch try1" $
+        eval' (TryCatch (CstInt 1) (CstInt 2))
+          @?= ([], Right (ValInt 1)),
+      --
+      testCase "TryCatch try2" $
+        eval' (TryCatch (CstInt 1) (Div (CstInt 1) (CstInt 0)))
+          @?= ([], Right (ValInt 1)),
+      --
+      testCase "TryCatch catch1" $
+        eval' (TryCatch (Div (CstInt 1) (CstInt 0)) (CstInt 1))
+          @?= ([], Right (ValInt 1)),
+      --
+      testCase "TryCatch catch1" $
+        eval' (TryCatch (Div (CstInt 1) (CstInt 0)) (Div (CstInt 1) (CstInt 0)))
           @?= ([], Left "Division by zero")
     ]