[planner] try bends=2 before bends=(2, 4)

masque/builder/planner/planner.py

@@ -50,6 +50,7 @@ from .interface import (
     PreparedRouteResult,
     RoutePlanningError,
     RoutePortContext,
+    route_error_is_fatal,
     )
 
 
@@ -908,6 +909,12 @@ class RoutingPlanner:
 
     TRACE_INTO_MAX_BENDS: int = 4
 
+    def trace_into_bend_budgets(self, family: PrimitiveKind) -> tuple[int, ...]:
+        """Return staged trace_into bend budgets for the route rotation parity."""
+        if family == 'bend':
+            return tuple(budget for budget in (1, 3) if budget <= self.TRACE_INTO_MAX_BENDS)
+        return tuple(budget for budget in (2, 4) if budget <= self.TRACE_INTO_MAX_BENDS)
+
     def plan_leg(
             self,
             family: PrimitiveKind,
@@ -1197,17 +1204,30 @@ 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 = 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=self.TRACE_INTO_MAX_BENDS,
-            **(dict(kwargs) | {'out_ptype': out_ptype}),
-            )
+        leg = None
+        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,
+                    **(dict(kwargs) | {'out_ptype': out_ptype}),
+                    )
+                break
+            except (BuildError, NotImplementedError) as err:
+                if route_error_is_fatal(err):
+                    raise
+                last_error = err
+        if leg is None:
+            if last_error is not None:
+                raise last_error
+            raise BuildError('No legal primitive offer for trace_into route')
         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

@@ -6,6 +6,8 @@ from numpy import pi
 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.tools import BendOffer, PrimitiveOffer, StraightOffer, Tool
 from masque.error import BuildError, PortError
 
@@ -260,3 +262,78 @@ def test_pather_trace_into_rejects_reserved_route_kwargs(
     assert p.pattern.ports['B'].rotation is not None
     assert numpy.isclose(p.pattern.ports['B'].rotation, dst.rotation)
     assert len(p._paths['A']) == 0
+
+
+class TraceIntoBudgetPlanner(RoutingPlanner):
+    def __init__(self, successes: set[int], fatal_at: set[int] | None = None) -> None:
+        self.successes = successes
+        self.fatal_at = set() if fatal_at is None else fatal_at
+        self.attempts: list[int | None] = []
+
+    def plan_leg(
+            self,
+            family: Any,
+            context: RoutePortContext,
+            *,
+            length: float | None = None,
+            jog: float | None = None,
+            ccw: Any = None,
+            plug_into: str | None = None,
+            constrain_jog: bool = False,
+            max_bends: int | None = None,
+            **kwargs: Any,
+            ) -> RouteLeg:
+        _ = family, length, jog, ccw, constrain_jog, kwargs
+        self.attempts.append(max_bends)
+        if max_bends in self.fatal_at:
+            raise RoutePlanningError('fatal', fatal=True)
+        if max_bends not in self.successes:
+            raise BuildError('try next budget')
+        return RouteLeg(
+            portspec=context.portspec,
+            start_port=context.port.copy(),
+            tool=context.tool,
+            candidate=Candidate((), context.port.copy(), 0.0, 0, 0.0),
+            plug_into=plug_into,
+            )
+
+    def prepared_result_from_legs(
+            self,
+            legs: Any,
+            *,
+            renames: tuple[tuple[str, str], ...] = (),
+            ) -> PreparedRouteResult:
+        _ = legs, renames
+        return PreparedRouteResult(())
+
+
+@pytest.mark.parametrize(
+    ('dst', 'successes', 'attempts'),
+    [
+        (Port((-10, 0), rotation=pi, ptype='wire'), {2}, [2]),
+        (Port((-10, 0), rotation=pi, ptype='wire'), {4}, [2, 4]),
+        (Port((-10, -10), rotation=3 * pi / 2, ptype='wire'), {1}, [1]),
+        (Port((-10, -10), rotation=3 * pi / 2, ptype='wire'), {3}, [1, 3]),
+    ],
+)
+def test_trace_into_uses_staged_bend_budgets(
+        dst: Port,
+        successes: set[int],
+        attempts: list[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
+
+
+def test_trace_into_staged_bend_budget_stops_on_fatal_error() -> None:
+    planner = TraceIntoBudgetPlanner({4}, fatal_at={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]