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Hypergraph

OpenHypergraph dataclass

An open hypergraph with input and output nodes.

Source code in src/IsomorphismChecker_python_serial/hypergraph.py 
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@dataclass(slots=True)
class OpenHypergraph:
    """An open hypergraph with input and output nodes."""

    nodes: list[Node] = field(default_factory=list)
    edges: list[HyperEdge] = field(default_factory=list)

    input_nodes: list[int] = field(default_factory=list)
    output_nodes: list[int] = field(default_factory=list)

    # TODO: Improve efficiency by caching results and invalidating on changes
    def is_valid(self) -> bool:
        """Check if the hypergraph is valid."""
        if not self.nodes:
            return False

        if not self.edges:
            return False

        return True

    def check_nodes_in_graph(self, nodes) -> bool:
        """Check if all nodes are in the hypergraph."""
        return all(node < len(self.nodes) for node in nodes)

    def set_next_prev(self, edge: HyperEdge):
        """Set the next and previous edges for nodes based on edges in the hypergraph."""

        for (i, v) in enumerate(edge.sources):
            node = self.nodes[v]
            if node.next is None:
                node.next = EdgeInfo(edge.index, i, edge.label)
            else:
                warnings.warn(
                    "Nodes with multiple outgoing edges are not currently fully supported. Use with caution.",
                    UserWarning,
                )

        for (i, v) in enumerate(edge.targets):
            node = self.nodes[v]
            if node.prev is None:
                node.prev = EdgeInfo(edge.index, i, edge.label)
            else:
                warnings.warn(
                    "Nodes with multiple incoming edges are not currently fully supported. Use with caution.",
                    UserWarning,
                )

    def __post_init__(self):

        for edge in self.edges:

            if not self.check_nodes_in_graph(edge.sources + edge.targets):
                raise ValueError(f"Edge {edge.label} has nodes not in hypergraph nodes")

            self.set_next_prev(edge)

check_nodes_in_graph(nodes)

Check if all nodes are in the hypergraph.

Source code in src/IsomorphismChecker_python_serial/hypergraph.py 
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def check_nodes_in_graph(self, nodes) -> bool:
    """Check if all nodes are in the hypergraph."""
    return all(node < len(self.nodes) for node in nodes)

is_valid()

Check if the hypergraph is valid.

Source code in src/IsomorphismChecker_python_serial/hypergraph.py 
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def is_valid(self) -> bool:
    """Check if the hypergraph is valid."""
    if not self.nodes:
        return False

    if not self.edges:
        return False

    return True

set_next_prev(edge)

Set the next and previous edges for nodes based on edges in the hypergraph.

Source code in src/IsomorphismChecker_python_serial/hypergraph.py 
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def set_next_prev(self, edge: HyperEdge):
    """Set the next and previous edges for nodes based on edges in the hypergraph."""

    for (i, v) in enumerate(edge.sources):
        node = self.nodes[v]
        if node.next is None:
            node.next = EdgeInfo(edge.index, i, edge.label)
        else:
            warnings.warn(
                "Nodes with multiple outgoing edges are not currently fully supported. Use with caution.",
                UserWarning,
            )

    for (i, v) in enumerate(edge.targets):
        node = self.nodes[v]
        if node.prev is None:
            node.prev = EdgeInfo(edge.index, i, edge.label)
        else:
            warnings.warn(
                "Nodes with multiple incoming edges are not currently fully supported. Use with caution.",
                UserWarning,
            )

Utility Functions