Strict Execution

frontend/src/components/editor/output/MarimoErrorOutput.tsx

@@ -139,6 +139,37 @@ export const MarimoErrorOutput = ({
             </Tip>
           </div>
         );
+      case "strict-exception":
+        return error.blamed_cell == null ? (
+          <Fragment key={idx}>
+            <p>{error.msg}</p>
+            <Tip>
+              Something is wrong with your declaration of {error.ref}. Fix any
+              discrepancies, or turn off strict execution.
+            </Tip>
+          </Fragment>
+        ) : (
+          <div key={idx}>
+            {error.msg}
+            <CellLinkError cellId={error.blamed_cell} />
+            <Tip>
+              Ensure that <CellLinkError cellId={error.blamed_cell} />
+              defines the variable {error.ref}, or turn off strict execution.
+            </Tip>
+          </div>
+        );
+      case "ancestor-prevented":
+        titleContents = "Ancestor prevented from running";
+        alertVariant = "default";
+        textColor = "text-secondary-foreground";
+        return (
+          <div key={idx}>
+            {error.msg}
+            (<CellLinkError cellId={error.raising_cell} />
+            blames
+            <CellLinkError cellId={error.blamed_cell} />)
+          </div>
+        );
       case "ancestor-stopped":
         titleContents = "Ancestor stopped";
         alertVariant = "default";

frontend/src/core/cells/cell.ts

@@ -74,7 +74,7 @@ export function transitionCell(
       nextCell.interrupted = true;
       didInterruptFromThisMessage = true;
     } else if (
-      message.output.data.some((error) => error.type === "ancestor-stopped")
+      message.output.data.some((error) => error.type.includes("ancestor"))
     ) {
       // The cell didn't run, but it was intentional, so don't count as
       // errored.

frontend/src/core/cells/cells.ts

@@ -742,7 +742,7 @@ const cellErrorsAtom = atom((get) => {
         // These are errors that are caused by a cell that was stopped,
         // but nothing the user can take action on.
         const nonAncestorErrors = cell.output.data.filter(
-          (error) => error.type !== "ancestor-stopped",
+          (error) => !error.type.includes("ancestor"),
         );
 
         if (nonAncestorErrors.length > 0) {

frontend/src/core/kernel/messages.ts

@@ -28,10 +28,22 @@ export type MarimoError =
       msg: string;
       raising_cell?: CellId;
     }
+  | {
+      type: "ancestor-prevented";
+      msg: string;
+      raising_cell: CellId;
+      blamed_cell: CellId;
+    }
   | { type: "ancestor-stopped"; msg: string; raising_cell: CellId }
   | { type: "cycle"; edges_with_vars: Array<[CellId, string[], CellId]> }
   | { type: "multiple-defs"; name: string; cells: CellId[] }
   | { type: "delete-nonlocal"; name: string; cells: CellId[] }
+  | {
+      type: "strict-exception";
+      msg: string;
+      ref: string;
+      blamed_cell: CellId;
+    }
   | { type: "unknown"; msg?: string };
 
 export type OutputMessage =

marimo/_ast/app.py

@@ -20,8 +20,6 @@
     Cell,
     CellConfig,
     CellId_t,
-    execute_cell,
-    execute_cell_async,
 )
 from marimo._ast.compiler import cell_factory
 from marimo._ast.errors import (
@@ -36,6 +34,10 @@
 from marimo._messaging.types import NoopStream
 from marimo._output.rich_help import mddoc
 from marimo._runtime import dataflow
+from marimo._runtime.executor import (
+    execute_cell,
+    execute_cell_async,
+)
 from marimo._runtime.patches import patch_main_module_context
 
 if TYPE_CHECKING:
@@ -271,7 +273,7 @@ def _run_sync(
                     self._execution_context = ExecutionContext(
                         cell_id=cid, setting_element_value=False
                     )
-                    outputs[cid] = execute_cell(cell._cell, glbls)
+                    outputs[cid] = execute_cell(cell._cell, glbls, self._graph)
                     for hook in post_execute_hooks:
                         hook()
             return self._outputs_and_defs(outputs, glbls)
@@ -293,7 +295,9 @@ async def _run_async(
                     self._execution_context = ExecutionContext(
                         cell_id=cid, setting_element_value=False
                     )
-                    outputs[cid] = await execute_cell_async(cell._cell, glbls)
+                    outputs[cid] = await execute_cell_async(
+                        cell._cell, glbls, self._graph
+                    )
                     for hook in post_execute_hooks:
                         hook()
                     self._execution_context = None

marimo/_ast/cell.py

@@ -434,27 +434,3 @@ def __call__(self, *args: Any, **kwargs: Any) -> None:
 
 def is_ws(char: str) -> bool:
     return char == " " or char == "\n" or char == "\t"
-
-
-async def execute_cell_async(cell: CellImpl, glbls: dict[Any, Any]) -> Any:
-    if cell.body is None:
-        return None
-    assert cell.last_expr is not None
-
-    if _is_coroutine(cell.body):
-        await eval(cell.body, glbls)
-    else:
-        exec(cell.body, glbls)
-
-    if _is_coroutine(cell.last_expr):
-        return await eval(cell.last_expr, glbls)
-    else:
-        return eval(cell.last_expr, glbls)
-
-
-def execute_cell(cell: CellImpl, glbls: dict[Any, Any]) -> Any:
-    if cell.body is None:
-        return None
-    assert cell.last_expr is not None
-    exec(cell.body, glbls)
-    return eval(cell.last_expr, glbls)

marimo/_ast/compiler.py

@@ -18,8 +18,9 @@
     CellId_t,
     CellImpl,
 )
-from marimo._ast.visitor import ScopedVisitor, is_local
+from marimo._ast.visitor import ScopedVisitor
 from marimo._utils.tmpdir import get_tmpdir
+from marimo._utils.variables import is_local
 
 if TYPE_CHECKING:
     from collections.abc import Iterator