[planner] make solver carry state across increasing bend counts

masque/builder/planner/planner.py

@@ -293,16 +293,24 @@ class Solver:
             tuple[PrimitiveKind, str | None, str | None, tuple[tuple[str, Any], ...]],
             tuple[PrimitiveOffer, ...],
             ] = {}
+        self.seen_candidate_keys: set[tuple[Any, ...]] = set()
         self.order = 0
 
-    def solve(self) -> Candidate:
+    @staticmethod
-        """
+    def route_bend_count(steps: Sequence[SelectedPrimitive]) -> int:
-        Enumerate, finalize, deduplicate, and rank legal candidates.
+        """Return the route bend budget consumed by non-adapter primitives."""
+        count = 0
+        for step in steps:
+            if step.role == 'adapter':
+                continue
+            if step.route_kind == 'bend':
+                count += 1
+            elif step.route_kind in ('s', 'u'):
+                count += 2
+        return count
 
-        Non-fatal candidate errors are accumulated so the failure message can
+    def candidate_key(self, candidate: Candidate) -> tuple[Any, ...]:
-        preserve useful Tool feedback. Fatal offer-contract errors stop the
+        """Return a deterministic key for duplicate solved candidates."""
-        solve immediately.
-        """
         def endpoint_key(port: Port) -> tuple[float, float, float | None, str | None]:
             return (
                 round(float(port.x), 9),
@@ -311,7 +319,6 @@ class Solver:
                 port.ptype,
                 )
 
-        def candidate_key(candidate: Candidate) -> tuple[Any, ...]:
         def offer_key(offer: PrimitiveOffer) -> tuple[Any, ...]:
             return (
                 type(offer).__qualname__,
@@ -335,12 +342,28 @@ class Solver:
                 ) for step in candidate.steps),
             )
 
+    def solve(
+            self,
+            *,
+            min_bends: int = 0,
+            max_bends: int | None = None,
+            ) -> Candidate:
+        """
+        Enumerate, finalize, deduplicate, and rank legal candidates.
+
+        Non-fatal candidate errors are accumulated so the failure message can
+        preserve useful Tool feedback. Fatal offer-contract errors stop the
+        solve immediately.
+        """
+        if max_bends is None:
+            max_bends = self.request.bend_budget
         candidates: list[Candidate] = []
         errors: list[Exception] = []
-        seen: set[tuple[Any, ...]] = set()
+        for steps in self.enumerate_grammar(max_bends):
-        for steps in self.enumerate_grammar():
             if not steps:
                 continue
+            if self.route_bend_count(steps) < min_bends:
+                continue
             if any(first.role == 'adapter' and second.role == 'adapter' for first, second in zip(steps, steps[1:], strict=False)):
                 continue
             try:
@@ -349,10 +372,10 @@ class Solver:
                 raise_if_fatal(err)
                 errors.append(err)
                 continue
-            key = candidate_key(candidate)
+            key = self.candidate_key(candidate)
-            if key in seen:
+            if key in self.seen_candidate_keys:
                 continue
-            seen.add(key)
+            self.seen_candidate_keys.add(key)
             candidates.append(candidate)
 
         if not candidates:
@@ -676,13 +699,13 @@ class Solver:
             options.extend((turn, 2) for turn in self.su_primitive_options(steps, 'u', jog))
         return tuple(options)
 
-    def enumerate_grammar(self) -> Iterable[tuple[SelectedPrimitive, ...]]:
+    def enumerate_grammar(self, max_bends: int) -> Iterable[tuple[SelectedPrimitive, ...]]:
         """Yield raw primitive sequences allowed by the bounded route grammar."""
         residual_jog = 0.0 if self.request.jog is None else float(self.request.jog)
         base: tuple[SelectedPrimitive, ...] = ()
         for prefix_adapter in self.adapter_options(base, residual_jog=residual_jog):
             prefix = (*base, *prefix_adapter)
-            yield from self.enumerate_segments(prefix, self.request.bend_budget, residual_jog=residual_jog)
+            yield from self.enumerate_segments(prefix, max_bends, residual_jog=residual_jog)
 
     def enumerate_segments(
             self,
@@ -909,11 +932,63 @@ class RoutingPlanner:
 
     TRACE_INTO_MAX_BENDS: int = 4
 
-    def trace_into_bend_budgets(self, family: PrimitiveKind) -> tuple[int, ...]:
+    def trace_into_bend_bands(self, family: PrimitiveKind) -> tuple[tuple[int, int], ...]:
-        """Return staged trace_into bend budgets for the route rotation parity."""
+        """Return non-overlapping trace_into bend-budget bands for staged solving."""
+        max_bends = self.TRACE_INTO_MAX_BENDS
         if family == 'bend':
-            return tuple(budget for budget in (1, 3) if budget <= self.TRACE_INTO_MAX_BENDS)
+            return tuple(band for band in ((1, 1), (3, 3)) if band[1] <= max_bends)
-        return tuple(budget for budget in (2, 4) if budget <= self.TRACE_INTO_MAX_BENDS)
+        bands: list[tuple[int, int]] = []
+        if max_bends >= 0:
+            bands.append((0, 2 if max_bends >= 2 else 0))
+        if max_bends >= 4:
+            bands.append((4, 4))
+        return tuple(bands)
+
+    def route_request(
+            self,
+            family: PrimitiveKind,
+            context: RoutePortContext,
+            *,
+            length: float | None = None,
+            jog: float | None = None,
+            ccw: SupportsBool | None = None,
+            constrain_jog: bool = False,
+            max_bends: int | None = None,
+            **kwargs: Any,
+            ) -> RouteRequest:
+        """Build normalized solver input for one route leg."""
+        return RouteRequest(
+            family=family,
+            tool=context.tool,
+            in_ptype=context.port.ptype,
+            route_kwargs=kwargs,
+            length=length,
+            jog=jog,
+            ccw=ccw,
+            out_ptype=kwargs.get('out_ptype'),
+            constrain_jog=constrain_jog,
+            max_bends=max_bends,
+            )
+
+    def solver_for_request(self, request: RouteRequest) -> Solver:
+        """Construct the solver for a route request."""
+        return Solver(request)
+
+    def route_leg_from_candidate(
+            self,
+            context: RoutePortContext,
+            candidate: Candidate,
+            *,
+            plug_into: str | None,
+            ) -> RouteLeg:
+        """Attach a solved candidate to its source Pather context."""
+        return RouteLeg(
+            portspec=context.portspec,
+            start_port=context.port.copy(),
+            tool=context.tool,
+            candidate=candidate,
+            plug_into=plug_into,
+            )
 
     def plan_leg(
             self,
@@ -929,31 +1004,23 @@ class RoutingPlanner:
             **kwargs: Any,
             ) -> RouteLeg:
         """Solve one route leg and attach it to its source Pather context."""
-        request = RouteRequest(
+        request = self.route_request(
             family=family,
-            tool=context.tool,
+            context=context,
-            in_ptype=context.port.ptype,
-            route_kwargs=kwargs,
             length=length,
             jog=jog,
             ccw=ccw,
-            out_ptype=kwargs.get('out_ptype'),
             constrain_jog=constrain_jog,
             max_bends=max_bends,
+            **kwargs,
             )
         try:
-            candidate = Solver(request).solve()
+            candidate = self.solver_for_request(request).solve()
         except BuildError as err:
             if family == 'u' and length is None and not getattr(err, 'fatal', False):
                 raise BuildError('No legal primitive offer for omitted-length U-turn') from err
             raise
-        return RouteLeg(
+        return self.route_leg_from_candidate(context, candidate, plug_into=plug_into)
-            portspec=context.portspec,
-            start_port=context.port.copy(),
-            tool=context.tool,
-            candidate=candidate,
-            plug_into=plug_into,
-            )
 
     def prepared_route_action_from_leg(
             self,
@@ -1204,30 +1271,36 @@ class RoutingPlanner:
         desired.rotation = port_dst.rotation - pi
         desired.ptype = out_ptype
         family, length, jog, ccw = self.trace_into_spec(context_src.port, desired)
-        leg = None
+        request = self.route_request(
-        last_error: Exception | None = None
-        for max_bends in self.trace_into_bend_budgets(family):
-            try:
-                leg = self.plan_leg(
             family,
             context_src,
             length=length,
             jog=jog,
             ccw=ccw,
-                    plug_into=portspec_dst if plug_destination else None,
             constrain_jog=family == 'bend',
-                    max_bends=max_bends,
+            max_bends=self.TRACE_INTO_MAX_BENDS,
             **(dict(kwargs) | {'out_ptype': out_ptype}),
             )
+        solver = self.solver_for_request(request)
+        candidate = None
+        last_error: Exception | None = None
+        for min_bends, max_bends in self.trace_into_bend_bands(family):
+            try:
+                candidate = solver.solve(min_bends=min_bends, max_bends=max_bends)
                 break
             except (BuildError, NotImplementedError) as err:
                 if route_error_is_fatal(err):
                     raise
                 last_error = err
-        if leg is None:
+        if candidate is None:
             if last_error is not None:
                 raise last_error
             raise BuildError('No legal primitive offer for trace_into route')
+        leg = self.route_leg_from_candidate(
+            context_src,
+            candidate,
+            plug_into=portspec_dst if plug_destination else None,
+            )
         renames = ((thru, context_src.portspec),) if thru is not None else ()
         return self.prepared_result_from_legs(
             (leg,),

masque/test/test_pather_trace_into.py

@@ -7,7 +7,7 @@ from numpy.testing import assert_equal
 
 from masque import Library, PathTool, Port, Pather
 from masque.builder.planner import PreparedRouteResult, RoutePlanningError, RoutePortContext, RoutingPlanner
-from masque.builder.planner.planner import Candidate, RouteLeg
+from masque.builder.planner.planner import Candidate, RouteRequest
 from masque.builder.tools import BendOffer, PrimitiveOffer, StraightOffer, Tool
 from masque.error import BuildError, PortError
 
@@ -264,38 +264,37 @@ def test_pather_trace_into_rejects_reserved_route_kwargs(
     assert len(p._paths['A']) == 0
 
 
-class TraceIntoBudgetPlanner(RoutingPlanner):
+class TraceIntoBudgetSolver:
-    def __init__(self, successes: set[int], fatal_at: set[int] | None = None) -> None:
+    def __init__(self, successes: set[tuple[int, int]], fatal_at: set[tuple[int, int]] | None = None) -> None:
         self.successes = successes
         self.fatal_at = set() if fatal_at is None else fatal_at
-        self.attempts: list[int | None] = []
+        self.attempts: list[tuple[int, int]] = []
 
-    def plan_leg(
+    def solve(
             self,
-            family: Any,
-            context: RoutePortContext,
             *,
-            length: float | None = None,
+            min_bends: int = 0,
-            jog: float | None = None,
-            ccw: Any = None,
-            plug_into: str | None = None,
-            constrain_jog: bool = False,
             max_bends: int | None = None,
-            **kwargs: Any,
+            ) -> Candidate:
-            ) -> RouteLeg:
+        assert max_bends is not None
-        _ = family, length, jog, ccw, constrain_jog, kwargs
+        band = (min_bends, max_bends)
-        self.attempts.append(max_bends)
+        self.attempts.append(band)
-        if max_bends in self.fatal_at:
+        if band in self.fatal_at:
             raise RoutePlanningError('fatal', fatal=True)
-        if max_bends not in self.successes:
+        if band not in self.successes:
             raise BuildError('try next budget')
-        return RouteLeg(
+        return Candidate((), Port((0, 0), rotation=0, ptype='wire'), 0.0, 0, 0.0)
-            portspec=context.portspec,
+
-            start_port=context.port.copy(),
+
-            tool=context.tool,
+class TraceIntoBudgetPlanner(RoutingPlanner):
-            candidate=Candidate((), context.port.copy(), 0.0, 0, 0.0),
+    def __init__(self, successes: set[tuple[int, int]], fatal_at: set[tuple[int, int]] | None = None) -> None:
-            plug_into=plug_into,
+        self.solver = TraceIntoBudgetSolver(successes, fatal_at=fatal_at)
-            )
+        self.solver_requests = 0
+
+    def solver_for_request(self, request: RouteRequest) -> Any:
+        _ = request
+        self.solver_requests += 1
+        return self.solver
 
     def prepared_result_from_legs(
             self,
@@ -310,30 +309,43 @@ class TraceIntoBudgetPlanner(RoutingPlanner):
 @pytest.mark.parametrize(
     ('dst', 'successes', 'attempts'),
     [
-        (Port((-10, 0), rotation=pi, ptype='wire'), {2}, [2]),
+        (Port((-10, 0), rotation=pi, ptype='wire'), {(0, 2)}, [(0, 2)]),
-        (Port((-10, 0), rotation=pi, ptype='wire'), {4}, [2, 4]),
+        (Port((-10, 0), rotation=pi, ptype='wire'), {(4, 4)}, [(0, 2), (4, 4)]),
-        (Port((-10, -10), rotation=3 * pi / 2, ptype='wire'), {1}, [1]),
+        (Port((-10, -10), rotation=3 * pi / 2, ptype='wire'), {(1, 1)}, [(1, 1)]),
-        (Port((-10, -10), rotation=3 * pi / 2, ptype='wire'), {3}, [1, 3]),
+        (Port((-10, -10), rotation=3 * pi / 2, ptype='wire'), {(3, 3)}, [(1, 1), (3, 3)]),
     ],
 )
-def test_trace_into_uses_staged_bend_budgets(
+def test_trace_into_reuses_solver_across_staged_bend_bands(
         dst: Port,
-        successes: set[int],
+        successes: set[tuple[int, int]],
-        attempts: list[int],
+        attempts: list[tuple[int, int]],
         ) -> None:
     planner = TraceIntoBudgetPlanner(successes)
     context = RoutePortContext('src', Port((0, 0), rotation=0, ptype='wire'), PathTool(layer='M1', width=1, ptype='wire'))
 
     planner.plan_trace_into(context, 'dst', dst, out_ptype=None, plug_destination=True, thru=None)
 
-    assert planner.attempts == attempts
+    assert planner.solver.attempts == attempts
+    assert planner.solver_requests == 1
 
 
 def test_trace_into_staged_bend_budget_stops_on_fatal_error() -> None:
-    planner = TraceIntoBudgetPlanner({4}, fatal_at={2})
+    planner = TraceIntoBudgetPlanner({(4, 4)}, fatal_at={(0, 2)})
     context = RoutePortContext('src', Port((0, 0), rotation=0, ptype='wire'), PathTool(layer='M1', width=1, ptype='wire'))
 
     with pytest.raises(RoutePlanningError, match='fatal'):
         planner.plan_trace_into(context, 'dst', Port((-10, 0), rotation=pi, ptype='wire'), out_ptype=None, plug_destination=True, thru=None)
 
-    assert planner.attempts == [2]
+    assert planner.solver.attempts == [(0, 2)]
+    assert planner.solver_requests == 1
+
+
+def test_trace_into_bend_bands_respect_max_bends() -> None:
+    class OneBendPlanner(RoutingPlanner):
+        TRACE_INTO_MAX_BENDS = 1
+
+    planner = OneBendPlanner()
+
+    assert planner.trace_into_bend_bands('straight') == ((0, 0),)
+    assert planner.trace_into_bend_bands('s') == ((0, 0),)
+    assert planner.trace_into_bend_bands('bend') == ((1, 1),)