Merge pull request #45 from hyroai/fix-infer-sink

fix infer_sink: multiple future edges are to a single destination, then that is the sink

Author: molaxx

computation_graph/composers/__init__.py

@@ -107,6 +107,9 @@ def filter_computation_errors(*args):
     )
 
 
+_destinations = gamla.compose(set, gamla.map(base_types.edge_destination))
+
+
 def _infer_sink(graph_or_node: base_types.NodeOrGraph) -> base_types.ComputationNode:
     if isinstance(graph_or_node, base_types.ComputationNode):
         return graph_or_node
@@ -130,8 +133,8 @@ def _infer_sink(graph_or_node: base_types.NodeOrGraph) -> base_types.Computation
             assert len(result) == 1
             return gamla.head(result)
 
-    assert len(graph_or_node) == 1, graph_without_future_edges
-    return graph_or_node[0].destination
+    assert len(_destinations(graph_or_node)) == 1, graph_or_node
+    return base_types.edge_destination(graph_or_node[0])
 
 
 def make_first(*graphs: base_types.CallableOrNodeOrGraph) -> base_types.GraphType:

computation_graph/composers/composers_test.py

@@ -1,4 +1,5 @@
-from computation_graph import composers, graph_runners
+import computation_graph.graph
+from computation_graph import base_types, composers, graph_runners
 
 
 def test_unary_composition_with_graph_destination():
@@ -11,6 +12,20 @@ def test_unary_composition_with_graph_destination():
     assert result == -1
 
 
+def test_infer_sink_edge_case_all_future_edges_with_single_destination():
+    s = computation_graph.graph.make_source()
+
+    def c_b(c, b):
+        return b
+
+    two_future_edges_single_dest = base_types.merge_graphs(
+        composers.compose_left_source(s, "c", c_b),
+        composers.compose_left_source(s, "b", c_b),
+    )
+
+    composers.compose_left_unary(two_future_edges_single_dest, lambda x: x)
+
+
 def test_ambiguity_does_not_blow_up():
     counter = 0
 

setup.py

@@ -7,7 +7,7 @@
 setuptools.setup(
     name="computation-graph",
     python_requires=">=3",
-    version="37",
+    version="38",
     long_description=_LONG_DESCRIPTION,
     long_description_content_type="text/markdown",
     packages=setuptools.find_namespace_packages(),