Requirement Boolean Negation Fix (#289)

* Added test to reproduce Issue#286

* Initial attempt for not transforming not.

* convert globals used in requirements to distributions as needed

* Simplified test.

* Update src/scenic/syntax/compiler.py

Co-authored-by: Daniel Fremont <[email protected]>

* Fixed renaming.

---------

Co-authored-by: Daniel Fremont <[email protected]>

src/scenic/core/requirements.py

@@ -9,7 +9,7 @@
 import rv_ltl
 import trimesh
 
-from scenic.core.distributions import Samplable, needsSampling
+from scenic.core.distributions import Samplable, needsSampling, toDistribution
 from scenic.core.errors import InvalidScenarioError
 from scenic.core.lazy_eval import needsLazyEvaluation
 from scenic.core.propositions import Atomic, PropositionNode
@@ -71,6 +71,10 @@ def compile(self, namespace, scenario, syntax=None):
         bindings, ego, line = self.bindings, self.egoObject, self.line
         condition, ty = self.condition, self.ty
 
+        # Convert bound values to distributions as needed
+        for name, value in bindings.items():
+            bindings[name] = toDistribution(value)
+
         # Check whether requirement implies any relations used for pruning
         canPrune = condition.check_constrains_sampling()
         if canPrune:

src/scenic/syntax/compiler.py

@@ -240,6 +240,7 @@ class PropositionTransformer(Transformer):
     def __init__(self, filename="<unknown>") -> None:
         super().__init__(filename)
         self.nextSyntaxId = 0
+        self.inAtomic = False
 
     def transform(
         self, node: ast.AST, nextSyntaxId=0
@@ -260,6 +261,14 @@ def transform(
         newNode = self._create_atomic_proposition_factory(node)
         return newNode, self.nextSyntaxId
 
+    def generic_visit(self, node):
+        # Don't recurse inside atomics.
+        old_inAtomic = self.inAtomic
+        self.inAtomic = True
+        super_val = super().generic_visit(node)
+        self.inAtomic = old_inAtomic
+        return super_val
+
     def _register_requirement_syntax(self, syntax):
         """register requirement syntax for later use
         returns an ID for retrieving the syntax
@@ -337,7 +346,7 @@ def visit_BoolOp(self, node: ast.BoolOp) -> ast.AST:
 
     def visit_UnaryOp(self, node):
         # rewrite `not` in requirements into a proposition factory
-        if not isinstance(node.op, ast.Not):
+        if not isinstance(node.op, ast.Not) or self.inAtomic:
             return self.generic_visit(node)
 
         lineNum = ast.Constant(node.lineno)

tests/syntax/test_requirements.py

@@ -497,3 +497,14 @@ def test_random_occlusion():
         hasattr(obj, "name") and obj.name == "wall" and (not obj.occluding)
         for obj in scene.objects
     )
+
+
+def test_deep_not():
+    """Test that a not deep inside a requirement is interpreted correctly."""
+    with pytest.raises(RejectionException):
+        sampleSceneFrom(
+            """
+            objs = [new Object at 10@10, new Object at 20@20]
+            require all(not o.x > 0 for o in objs)
+            """
+        )