[Pather] add route completion callback

masque/builder/__init__.py

@@ -57,6 +57,7 @@ for custom Tools.
 from .pather import (
     Pather as Pather,
     PortPather as PortPather,
+    RouteCompletionCallback as RouteCompletionCallback,
 )
 from .error import (
     ToolContractError as ToolContractError,

masque/builder/pather.py

@@ -46,7 +46,7 @@ Rendering is not transactional across Pattern and Library mutations. A render
 exception is terminal for that Pather: callers may catch it for reporting or
 cleanup, but must not retry rendering or continue routing with the same object.
 """
-from typing import Self, Any, Literal, overload
+from typing import Self, Any, Literal, Protocol, overload
 from collections.abc import Iterator, Iterable, Mapping, MutableMapping, Sequence
 import copy
 import logging
@@ -56,6 +56,7 @@ from pprint import pformat
 from contextlib import contextmanager
 from itertools import chain
 from types import TracebackType
+from types import MappingProxyType
 
 import numpy
 from numpy import pi
@@ -92,6 +93,19 @@ RENDER_POLICIES: tuple[RenderPolicy, ...] = ('auto', 'immediate', 'deferred', 'w
 RESERVED_TOOL_OPTION_KEYS = frozenset(('kind', 'in_ptype', 'out_ptype', 'ccw'))
 
 
+class RouteCompletionCallback(Protocol):
+    """Callback invoked after one routing operation updates live Pather state."""
+
+    def __call__(
+            self,
+            pather: 'Pather',
+            endpoints: Mapping[str, Port],
+            /,
+            ) -> None:
+        """Handle copied final endpoints keyed by their original routed names."""
+        ...
+
+
 def _present_route_args(**kwargs: Any) -> dict[str, Any]:
     """Return explicitly supplied route arguments for planner validation."""
     return {key: value for key, value in kwargs.items() if value is not None}
@@ -144,10 +158,25 @@ class Pather(PortList):
     - `pather.trace('my_port', ccw=True, length=100)` plans a 100-unit bend
         starting at 'my_port'. If the `Pather` is used as a context manager,
         geometry is generated on clean context exit.
+
+    Examples: Route completion
+    ==========================
+    Route completion callbacks can add labels or other endpoint annotations
+    without wrapping the individual routing methods::
+
+        def label_route_endpoints(pather, endpoints):
+            for name, port in endpoints.items():
+                pather.label('PORT_LABELS', string=name, offset=port.offset)
+
+        pather = Pather(
+            library,
+            tools=my_tool,
+            on_route_complete=label_route_endpoints,
+            )
     """
     __slots__ = (
         'pattern', 'library', 'tools', 'planner', '_paths',
-        '_dead', '_logger', '_render_policy', '_render_append', '_context_depth'
+        'on_route_complete', '_dead', '_logger', '_render_policy', '_render_append', '_context_depth'
     )
 
     pattern: Pattern
@@ -173,6 +202,9 @@ class Pather(PortList):
     than on the planner instance.
     """
 
+    on_route_complete: RouteCompletionCallback | None
+    """Optional callback run once after each routing operation updates live state."""
+
     _dead: bool
     """ If True, geometry generation is skipped (for debugging) """
 
@@ -238,6 +270,7 @@ class Pather(PortList):
             render: RenderPolicy = 'auto',
             render_append: bool = True,
             planner: RoutingPlanner | None = None,
+            on_route_complete: RouteCompletionCallback | None = None,
             ) -> None:
         """
         Args:
@@ -259,6 +292,11 @@ class Pather(PortList):
                 whether to append geometry or add a reference.
             planner: Optional stateless route-selection planner. If omitted,
                 a new `RoutingPlanner` is used.
+            on_route_complete: Optional callback invoked once per routing
+                operation after port updates, plugs, and renames, but before
+                automatic rendering. It receives this Pather and a read-only,
+                request-ordered mapping from original routed names to copied
+                final Ports. Callback exceptions propagate without rollback.
         """
         if render not in RENDER_POLICIES:
             raise BuildError(f'Invalid render policy {render!r}; expected one of {RENDER_POLICIES}')
@@ -271,6 +309,7 @@ class Pather(PortList):
         self.library = library
         self.pattern = pattern if pattern is not None else Pattern()
         self.planner = RoutingPlanner() if planner is None else planner
+        self.on_route_complete = on_route_complete
         self._paths = defaultdict(list)
 
         if ports is not None:
@@ -500,6 +539,14 @@ class Pather(PortList):
     #
     # Routing Logic (Deferred / Incremental)
     #
+    def _notify_route_complete(self, endpoints: Iterable[tuple[str, Port]]) -> None:
+        """Invoke the configured route callback with isolated endpoint snapshots."""
+        callback = self.on_route_complete
+        if callback is None:
+            return
+        snapshots = MappingProxyType({name: port.copy() for name, port in endpoints})
+        callback(self, snapshots)
+
     def _apply_route_result(self, result: PreparedRouteResult) -> None:
         """
         Apply every action and deferred rename in a prepared route result.
@@ -521,6 +568,9 @@ class Pather(PortList):
                 self.plugged({action.portspec: action.plug_into})
         for old_name, new_name in result.renames:
             self.rename_ports({old_name: new_name})
+        self._notify_route_complete(
+            (action.portspec, action.final_port) for action in result.actions
+            )
         render_immediately = (
             self._render_policy == 'immediate'
             or (self._render_policy == 'auto' and self._context_depth == 0)
@@ -539,7 +589,7 @@ class Pather(PortList):
             *,
             out_rot: float | None = None,
             out_ptype: str | None = None,
-            ) -> None:
+            ) -> Port:
         """
         Move a dead Pather port without generating geometry.
 
@@ -564,6 +614,7 @@ class Pather(PortList):
         self.pattern.ports[portspec] = out_port
         if plug_into is not None:
             self.plugged({portspec: plug_into})
+        return out_port.copy()
 
     #
     # High-level Routing Methods
@@ -639,7 +690,7 @@ class Pather(PortList):
                     raise
                 if length is not None and len(contexts) == 1:
                     context = contexts[0]
-                    self._apply_dead_fallback(
+                    endpoint = self._apply_dead_fallback(
                         context.portspec,
                         length,
                         0,
@@ -647,11 +698,13 @@ class Pather(PortList):
                         context.port.ptype,
                         out_ptype = out_ptype,
                         )
+                    self._notify_route_complete(((context.portspec, endpoint),))
                     return self
                 if bounds.get('each') is not None:
                     each = bounds['each']
+                    endpoints: list[tuple[str, Port]] = []
                     for context in contexts:
-                        self._apply_dead_fallback(
+                        endpoint = self._apply_dead_fallback(
                             context.portspec,
                             each,
                             0,
@@ -659,6 +712,8 @@ class Pather(PortList):
                             context.port.ptype,
                             out_ptype = out_ptype,
                             )
+                        endpoints.append((context.portspec, endpoint))
+                    self._notify_route_complete(endpoints)
                     return self
                 raise
             self._apply_route_result(result)
@@ -755,7 +810,7 @@ class Pather(PortList):
                         raise
                     _key, _value, length = resolved
                 context = contexts[0]
-                self._apply_dead_fallback(
+                endpoint = self._apply_dead_fallback(
                     context.portspec,
                     length,
                     0,
@@ -763,6 +818,7 @@ class Pather(PortList):
                     context.port.ptype,
                     out_ptype = out_ptype,
                     )
+                self._notify_route_complete(((context.portspec, endpoint),))
                 return self
             self._apply_route_result(result)
             return self
@@ -962,7 +1018,7 @@ class Pather(PortList):
                     if length is None:
                         raise
                     context = contexts[0]
-                    self._apply_dead_fallback(
+                    endpoint = self._apply_dead_fallback(
                         context.portspec,
                         length,
                         0,
@@ -970,10 +1026,11 @@ class Pather(PortList):
                         context.port.ptype,
                         out_ptype = out_ptype,
                         )
+                    self._notify_route_complete(((context.portspec, endpoint),))
                     return self
                 fallback_length = length if length is not None else 0
                 context = contexts[0]
-                self._apply_dead_fallback(
+                endpoint = self._apply_dead_fallback(
                     context.portspec,
                     fallback_length,
                     offset,
@@ -982,6 +1039,7 @@ class Pather(PortList):
                     out_rot = pi,
                     out_ptype = out_ptype,
                     )
+                self._notify_route_complete(((context.portspec, endpoint),))
                 return self
             self._apply_route_result(result)
             return self
@@ -1035,7 +1093,7 @@ class Pather(PortList):
                         ):
                     raise
                 context = contexts[0]
-                self._apply_dead_fallback(
+                endpoint = self._apply_dead_fallback(
                     context.portspec,
                     length,
                     offset,
@@ -1044,6 +1102,7 @@ class Pather(PortList):
                     out_rot = 0.0,
                     out_ptype = out_ptype,
                     )
+                self._notify_route_complete(((context.portspec, endpoint),))
                 return self
             self._apply_route_result(result)
             return self

masque/test/test_pather_route_completion.py

@@ -0,0 +1,166 @@
+from collections.abc import Mapping, Sequence
+from typing import Any, Literal
+
+import numpy
+import pytest
+
+from masque import Library, Pather, Port
+from masque.builder import PathTool, RenderStep, RouteCompletionCallback, Tool
+from masque.error import BuildError
+
+
+def test_route_completion_can_label_before_automatic_render() -> None:
+    calls = 0
+
+    def label_endpoints(pather: Pather, endpoints: Mapping[str, Port]) -> None:
+        nonlocal calls
+        calls += 1
+        assert not pather.pattern.has_shapes()
+        assert numpy.allclose(pather.ports['A'].offset, endpoints['A'].offset)
+        for name, port in endpoints.items():
+            pather.label('LABELS', string=name, offset=port.offset)
+
+    callback: RouteCompletionCallback = label_endpoints
+    p = Pather(
+        Library(),
+        tools=PathTool(layer='M1', width=1, ptype='wire'),
+        on_route_complete=callback,
+        )
+    p.ports['A'] = Port((0, 0), rotation=0, ptype='wire')
+
+    p.at('A').straight(5)
+
+    assert calls == 1
+    assert p.pattern.has_shapes()
+    assert len(p.pattern.labels['LABELS']) == 1
+    assert p.pattern.labels['LABELS'][0].string == 'A'
+    assert numpy.allclose(p.pattern.labels['LABELS'][0].offset, p.ports['A'].offset)
+
+
+def test_bundle_route_completion_is_ordered_read_only_and_isolated() -> None:
+    calls: list[Mapping[str, Port]] = []
+
+    def record(pather: Pather, endpoints: Mapping[str, Port]) -> None:
+        _ = pather
+        calls.append(endpoints)
+        with pytest.raises(TypeError):
+            endpoints['extra'] = Port((0, 0))  # type: ignore[index]
+        endpoints['B'].translate((100, 100))
+
+    p = Pather(
+        Library(),
+        tools=PathTool(layer='M1', width=1, ptype='wire'),
+        render='deferred',
+        on_route_complete=record,
+        )
+    p.ports['B'] = Port((0, 2), rotation=0, ptype='wire')
+    p.ports['A'] = Port((0, 0), rotation=0, ptype='wire')
+
+    p.trace(['A', 'B'], None, each=5)
+
+    assert len(calls) == 1
+    assert list(calls[0]) == ['A', 'B']
+    assert numpy.allclose(p.ports['A'].offset, (-5, 0))
+    assert numpy.allclose(p.ports['B'].offset, (-5, 2))
+
+
+def test_trace_into_completion_retains_consumed_source_endpoint() -> None:
+    calls: list[Mapping[str, Port]] = []
+
+    def record(pather: Pather, endpoints: Mapping[str, Port]) -> None:
+        assert set(pather.ports) == {'src'}
+        assert numpy.allclose(pather.ports['src'].offset, (20, 0))
+        calls.append(endpoints)
+
+    p = Pather(
+        Library(),
+        tools=PathTool(layer='M1', width=1, ptype='wire'),
+        render='deferred',
+        on_route_complete=record,
+        )
+    p.ports['src'] = Port((0, 0), rotation=0, ptype='wire')
+    p.ports['dst'] = Port((-10, 0), rotation=numpy.pi, ptype='wire')
+    p.ports['thru'] = Port((20, 0), rotation=0, ptype='wire')
+
+    p.trace_into('src', 'dst', thru='thru')
+
+    assert len(calls) == 1
+    assert list(calls[0]) == ['src']
+    assert numpy.allclose(calls[0]['src'].offset, (-10, 0))
+
+
+def test_route_completion_exception_propagates_before_render() -> None:
+    def fail(pather: Pather, endpoints: Mapping[str, Port]) -> None:
+        _ = pather, endpoints
+        raise RuntimeError('completion failed')
+
+    p = Pather(
+        Library(),
+        tools=PathTool(layer='M1', width=1, ptype='wire'),
+        on_route_complete=fail,
+        )
+    p.ports['A'] = Port((0, 0), rotation=0, ptype='wire')
+
+    with pytest.raises(RuntimeError, match='completion failed'):
+        p.straight('A', 5)
+
+    assert numpy.allclose(p.ports['A'].offset, (-5, 0))
+    assert p._paths['A']
+    assert not p.pattern.has_shapes()
+
+
+class NoRouteTool(Tool):
+    def primitive_offers(
+            self,
+            kind: Literal['straight', 'bend', 's', 'u'],
+            **kwargs: Any,
+            ) -> tuple[()]:
+        _ = kind, kwargs
+        return ()
+
+    def render(
+            self,
+            batch: Sequence[RenderStep],
+            *,
+            port_names: tuple[str, str] = ('A', 'B'),
+            **kwargs: Any,
+            ) -> Library:
+        _ = batch, port_names, kwargs
+        return Library()
+
+
+def test_dead_bundle_fallback_invokes_route_completion_once() -> None:
+    calls: list[Mapping[str, Port]] = []
+    p = Pather(
+        Library(),
+        tools=NoRouteTool(),
+        on_route_complete=lambda _pather, endpoints: calls.append(endpoints),
+        )
+    p.ports['A'] = Port((0, 0), rotation=0, ptype='wire')
+    p.ports['B'] = Port((0, 2), rotation=0, ptype='wire')
+    p.set_dead()
+
+    p.trace(['B', 'A'], None, each=5)
+
+    assert len(calls) == 1
+    assert list(calls[0]) == ['B', 'A']
+    assert numpy.allclose(calls[0]['B'].offset, (-5, 2))
+    assert numpy.allclose(calls[0]['A'].offset, (-5, 0))
+    assert not p.pattern.has_shapes()
+
+
+def test_failed_route_does_not_invoke_route_completion() -> None:
+    calls = 0
+
+    def record(pather: Pather, endpoints: Mapping[str, Port]) -> None:
+        nonlocal calls
+        _ = pather, endpoints
+        calls += 1
+
+    p = Pather(Library(), tools=NoRouteTool(), on_route_complete=record)
+    p.ports['A'] = Port((0, 0), rotation=0, ptype='wire')
+
+    with pytest.raises(BuildError):
+        p.straight('A', 5)
+
+    assert calls == 0