refactor: consolidate Runner and app ScriptRunner

marimo/_ast/app.py

@@ -259,7 +259,6 @@ def __init__(self, **kwargs: Any) -> None:
         self._cell_manager = CellManager(prefix=cell_prefix)
         self._graph = dataflow.DirectedGraph()
         self._execution_context: ExecutionContext | None = None
-        self._runner = dataflow.Runner(self._graph)
         self._header: str | None = None
 
         self._unparsable_code: list[str] = []
@@ -780,17 +779,23 @@ def process_data(pd, batch_size, learning_rate):
     async def _run_cell_async(
         self, cell: Cell, kwargs: dict[str, Any]
     ) -> tuple[Any, _Namespace]:
+        from marimo._runtime.runner import by_kwargs
+
         self._maybe_initialize()
-        output, defs = await self._runner.run_cell_async(
-            cell._cell.cell_id, kwargs
+        output, defs = await by_kwargs.run_cell_async(
+            self._graph, cell._cell.cell_id, kwargs
         )
         return output, _Namespace(defs, owner=self)
 
     def _run_cell_sync(
         self, cell: Cell, kwargs: dict[str, Any]
     ) -> tuple[Any, _Namespace]:
+        from marimo._runtime.runner import by_kwargs
+
         self._maybe_initialize()
-        output, defs = self._runner.run_cell_sync(cell._cell.cell_id, kwargs)
+        output, defs = by_kwargs.run_cell_sync(
+            self._graph, cell._cell.cell_id, kwargs
+        )
         return output, _Namespace(defs, owner=self)
 
     async def _set_ui_element_value(
@@ -1000,11 +1005,6 @@ def set_execution_context(
     ) -> None:
         self._app._execution_context = execution_context
 
-    @property
-    def runner(self) -> dataflow.Runner:
-        self._app._maybe_initialize()
-        return self._app._runner
-
     def update_config(self, updates: dict[str, Any]) -> _AppConfig:
         return self.config.update(updates)
 

marimo/_ast/cell.py

@@ -481,8 +481,11 @@ def _is_coroutine(self) -> bool:
         if hasattr(self, "_is_coro_cached"):
             return self._is_coro_cached
         assert self._app is not None
-        self._is_coro_cached: bool = self._app.runner.is_coroutine(
-            self._cell.cell_id
+        from marimo._runtime.runner import by_kwargs
+
+        # ``graph`` triggers _maybe_initialize on the underlying App.
+        self._is_coro_cached: bool = by_kwargs.is_coroutine(
+            self._app.graph, self._cell.cell_id
         )
         return self._is_coro_cached
 
@@ -655,8 +658,15 @@ def add(mo, x, y):
                 }
                 refs = {**from_setup, **refs}
 
+        from marimo._runtime.runner import by_kwargs
+
         try:
-            if self._is_coroutine:
+            # Refresh the async decision with the caller's substitutions —
+            # an unsubstituted ancestor may have been async but isn't on
+            # this call's ancestor closure.
+            if by_kwargs.is_coroutine(
+                self._app.graph, self._cell.cell_id, refs
+            ):
                 return self._app.run_cell_async(cell=self, kwargs=refs)
             else:
                 return self._app.run_cell_sync(cell=self, kwargs=refs)

marimo/_messaging/tracebacks.py

@@ -49,10 +49,8 @@ def write_traceback(traceback: str) -> None:
         # In run mode, only forward to the frontend if show_tracebacks is on.
         if in_run_mode and not _show_tracebacks_enabled():
             return
-        # Strip marimo's internal executor.py frame and highlight for the UI
-        trimmed = _trim_traceback(traceback)
         sys.stderr._write_with_mimetype(
-            _highlight_traceback(trimmed),
+            _highlight_traceback(traceback),
             mimetype="application/vnd.marimo+traceback",
         )
     else:
@@ -64,16 +62,15 @@ def write_traceback(traceback: str) -> None:
             if in_run_mode and not _show_tracebacks_enabled():
                 sys.stderr.write(traceback)
                 return
-            trimmed = _trim_traceback(traceback)
             broadcast_notification(
                 CellNotification(
                     cell_id=ctx.cell_id,
                     console=CellOutput(
                         channel=CellChannel.STDERR,
                         mimetype="application/vnd.marimo+traceback",
-                        data=trimmed
+                        data=traceback
                         if code_mode
-                        else _highlight_traceback(trimmed),
+                        else _highlight_traceback(traceback),
                     ),
                 ),
                 ctx.stream,
@@ -83,27 +80,5 @@ def write_traceback(traceback: str) -> None:
             sys.stderr.write(traceback)
 
 
-def _trim_traceback(traceback: str) -> str:
-    """
-    Skip first DefaultExecutor.execute_cell traceback item which all traces start with.
-    """
-
-    lines = traceback.split("\n")
-    if (
-        len(lines) > 2
-        and lines[0] == "Traceback (most recent call last):"
-        and (
-            '/marimo/_runtime/executor.py", line ' in lines[1]
-            or '\\marimo\\_runtime\\executor.py", line ' in lines[1]
-        )
-        and lines[1].endswith(", in execute_cell")
-    ):
-        for i in range(2, len(lines)):
-            if lines[i].startswith("  File "):
-                return "\n".join(lines[:1] + lines[i:])
-
-    return traceback
-
-
 def is_code_highlighting(value: str) -> bool:
     return 'class="codehilite"' in value

marimo/_runtime/app/script_runner.py

@@ -2,7 +2,6 @@
 from __future__ import annotations
 
 import asyncio
-from collections import deque
 from typing import TYPE_CHECKING, Any
 
 from marimo._ast.names import SETUP_CELL_NAME
@@ -21,12 +20,17 @@
     MarimoRuntimeException,
     unwrap_user_exception,
 )
-from marimo._runtime.executor import resolve_executor
+from marimo._runtime.executor import (
+    Evaluator,
+    resolve_executor,
+)
 from marimo._runtime.patches import (
     create_main_module,
     extract_docstring_from_header,
     patch_main_module_context,
 )
+from marimo._runtime.runner.result import RunResult
+from marimo._runtime.runner.scheduler import SequentialScheduler
 from marimo._types.ids import CellId_t
 
 if TYPE_CHECKING:
@@ -47,7 +51,6 @@ def __init__(
         self.app = app
         self.filename = filename
         self._docstring = extract_docstring_from_header(app._app._header)
-        self.cells_cancelled: set[CellId_t] = set()
         self._glbls = glbls if glbls else {}
 
         # Setup cell cannot be overridden, and it's possible that some
@@ -59,24 +62,21 @@ def __init__(
             excluded=CellId_t(SETUP_CELL_NAME),
         )
 
-        self.cells_to_run: deque[CellId_t] = deque(
+        cells_to_run = [
             cid
             for cid in pruned_execution_order
             if app.cell_manager.cell_data_at(cid).cell is not None
             and not self.app.graph.is_disabled(cid)
-        )
-        self._executor = resolve_executor()
+        ]
 
-    def _cancel(self, cell_id: CellId_t) -> None:
-        cancelled = {
-            cid
-            for cid in dataflow.transitive_closure(self.app.graph, {cell_id})
-            if cid in self.cells_to_run
-        }
-        for cid in cancelled:
-            self.app.graph.cells[cid].set_run_result_status("cancelled")
-        self.cells_cancelled |= cancelled
+        self._scheduler = SequentialScheduler(cells_to_run, self.app.graph)
+        self._evaluator = Evaluator(executor=resolve_executor(), lifecycles=[])
 
+    # _run_synchronous and _run_asynchronous are deliberate near-twins:
+    # the only difference is the await on the cell step. Keeping them
+    # as separate methods (rather than wrapping with asyncio.run
+    # unconditionally) preserves the no-event-loop guarantee for purely
+    # synchronous apps.
     def _run_synchronous(
         self,
         post_execute_hooks: list[Callable[[], Any]],
@@ -93,39 +93,20 @@ def _run_synchronous(
             glbls.update(self._glbls)
 
             outputs: dict[CellId_t, Any] = {}
-            while self.cells_to_run:
-                cid = self.cells_to_run.popleft()
-                if cid in self.cells_cancelled:
+            while self._scheduler.pending():
+                cid = self._scheduler.pop_cell()
+                if self._scheduler.cancelled(cid):
                     continue
-                # Set up has already run in this case.
+                # Setup has already run by this point.
                 if cid == CellId_t(SETUP_CELL_NAME):
                     for hook in post_execute_hooks:
                         hook()
                     continue
-
                 cell = self.app.graph.cells[cid]
                 with get_context().with_cell_id(cid):
                     try:
-                        output = self._executor.execute_cell(cell, glbls)
-                        outputs[cid] = output
-                    except MarimoRuntimeException as e:
-                        unwrapped_exception = unwrap_user_exception(
-                            e, self.app.graph
-                        )
-
-                        if isinstance(unwrapped_exception, MarimoStopError):
-                            self._cancel(cid)
-                        elif isinstance(
-                            unwrapped_exception, MarimoMissingRefError
-                        ):
-                            name_err = unwrapped_exception.name_error
-                            raise (
-                                name_err
-                                if name_err is not None
-                                else unwrapped_exception
-                            ) from None
-                        else:
-                            raise
+                        result = self._evaluator.evaluate_sync(cell, glbls)
+                        self._handle_run_result(cid, result, outputs)
                     finally:
                         for hook in post_execute_hooks:
                             hook()
@@ -147,47 +128,63 @@ async def _run_asynchronous(
             glbls.update(self._glbls)
 
             outputs: dict[CellId_t, Any] = {}
-
-            while self.cells_to_run:
-                cid = self.cells_to_run.popleft()
-                if cid in self.cells_cancelled:
+            while self._scheduler.pending():
+                cid = self._scheduler.pop_cell()
+                if self._scheduler.cancelled(cid):
                     continue
-
+                # Setup has already run by this point.
                 if cid == CellId_t(SETUP_CELL_NAME):
                     for hook in post_execute_hooks:
                         hook()
                     continue
-
                 cell = self.app.graph.cells[cid]
                 with get_context().with_cell_id(cid):
                     try:
-                        output = await self._executor.execute_cell_async(
-                            cell, glbls
-                        )
-                        outputs[cid] = output
-                    except MarimoRuntimeException as e:
-                        unwrapped_exception = unwrap_user_exception(
-                            e, self.app.graph
-                        )
-
-                        if isinstance(unwrapped_exception, MarimoStopError):
-                            self._cancel(cid)
-                        elif isinstance(
-                            unwrapped_exception, MarimoMissingRefError
-                        ):
-                            name_err = unwrapped_exception.name_error
-                            raise (
-                                name_err
-                                if name_err is not None
-                                else unwrapped_exception
-                            ) from None
-                        else:
-                            raise
+                        result = await self._evaluator.evaluate(cell, glbls)
+                        self._handle_run_result(cid, result, outputs)
                     finally:
                         for hook in post_execute_hooks:
                             hook()
         return outputs, glbls
 
+    def _handle_run_result(
+        self,
+        cid: CellId_t,
+        result: RunResult,
+        outputs: dict[CellId_t, Any],
+    ) -> None:
+        """Classify the Evaluator's RunResult; record output, cancel, or raise.
+
+        Aligns MarimoStopError handling with the kernel classifier: the
+        stop's output is recorded for the cell and descendants are
+        cancelled, instead of silently swallowing both.
+        """
+        exc = result.exception
+        if exc is None:
+            outputs[cid] = result.output
+            return
+        if not isinstance(exc, BaseException):
+            # An Error-shape payload (e.g. ``MarimoStrictExecutionError``)
+            # from a lifecycle ``Skip(result=...)``. Script mode runs with
+            # no lifecycles today, so this is unreachable in practice;
+            # treat defensively by recording the output and cancelling
+            # descendants.
+            outputs[cid] = result.output
+            self._scheduler.cancel(cid)
+            return
+        if isinstance(exc, MarimoRuntimeException):
+            unwrapped = unwrap_user_exception(exc, self.app.graph)
+            if isinstance(unwrapped, MarimoStopError):
+                outputs[cid] = unwrapped.output
+                self._scheduler.cancel(cid)
+                return
+            if isinstance(unwrapped, MarimoMissingRefError):
+                name_err = unwrapped.name_error
+                raise (
+                    name_err if name_err is not None else unwrapped
+                ) from None
+        raise exc
+
     def run(self) -> RunOutput:
         from marimo._runtime.context.script_context import (
             initialize_script_context,
@@ -231,7 +228,7 @@ def run(self) -> RunOutput:
                     theme=get_context().marimo_config["display"]["theme"]
                 )
 
-            post_execute_hooks = []
+            post_execute_hooks: list[Callable[[], Any]] = []
             if DependencyManager.matplotlib.has():
                 from marimo._output.mpl import close_figures
 
@@ -249,25 +246,9 @@ def run(self) -> RunOutput:
                 )
             return outputs, defs
 
-        # Cell runner manages the exception handling for kernel
-        # runner, but script runner should raise the wrapped
-        # exception if invoked directly.
+        # Raise the wrapped user exception from "None" so the stack
+        # trace points at the failing cell, not the runner.
         except MarimoRuntimeException as e:
-            # MarimoMissingRefError, wraps the under lying NameError
-            # for context, so we raise the NameError directly.
-            if isinstance(e.__cause__, MarimoMissingRefError):
-                # For type checking + sanity check
-                if not isinstance(e.__cause__.name_error, NameError):
-                    raise MarimoRuntimeException(
-                        "Unexpected error occurred while running the app. "
-                        "Improperly wrapped MarimoMissingRefError exception. "
-                        "Please report this issue to "
-                        "https://github.com/marimo-team/marimo/issues"
-                    ) from e.__cause__
-                raise e.__cause__.name_error from e.__cause__
-            # For all other exceptions, we raise the wrapped exception
-            # from "None" to indicate this is an Error propagation, and to not
-            # muddy the stacktrace from the failing cells themselves.
             raise e.__cause__ from None  # type: ignore
         finally:
             if installed_script_context:

marimo/_runtime/dataflow/__init__.py

@@ -7,7 +7,6 @@
 from marimo import _loggers
 from marimo._ast.cell import CellImpl
 from marimo._runtime.dataflow.graph import DirectedGraph
-from marimo._runtime.dataflow.runner import Runner
 from marimo._runtime.dataflow.topology import GraphTopology
 from marimo._runtime.dataflow.types import Edge, EdgeWithVar
 from marimo._types.ids import CellId_t
@@ -253,7 +252,6 @@ def import_block_relatives(cid: CellId_t, children: bool) -> set[CellId_t]:
     "DirectedGraph",
     "Edge",
     "EdgeWithVar",
-    "Runner",
     "get_cycles",
     "get_import_block_relatives",
     "induced_subgraph",