Graph Class

The Forge Graph class wraps around the igraph.Graph object that is initialized by the graphical encoding provided by the graph-core API.

forge.relay.graph.graph.Graph(relay_expr: Relay.Node.obj, params: Optional[Union[dict, ParamsDict]] = None, sink_name: str = 'Sink')

Wrapper around igraph.Graph instances for graph-encoded Relay

This class provides a high-level API and context for working with Forge Nodes, enabling a 1-to-1 graphical representation of any Relay expression. It includes methods for traversal, transformation, and manipulation of the graph while maintaining Relay-specific semantics.

Initializes a Graph instance from a Relay expression.

Parameters:

Name	Type	Description	Default
relay_expr	obj	The Relay expression to encode as a graph.	required
params	Optional[Union[dict, ParamsDict]]	Optional parameters to associate with the graph.	None
sink_name	str	The name of the artificial sink vertex. Defaults to "Sink".	'Sink'

params: ParamsDict = params class-attribute instance-attribute

igraph: igraph.Graph = graph_core.from_relay(relay_expr, sink_name=sink_name, input_names=input_names) class-attribute instance-attribute

calibration: Dict[str, CalibrationMetaData] = field(init=False, factory=dict, repr=False) class-attribute instance-attribute

fingerprint: str property

Computes a unique fingerprint for the graph, a hash of structure and data

Returns:

Name	Type	Description
str	str	A string representing the graph's unique fingerprint.

inputs: List[Node] property

Retrieves the input nodes of the graph.

Returns:

Type	Description
List[Node]	List[Node]: A list of input nodes.

output: Node property

Retrieves the output node of the graph.

Returns:

Name	Type	Description
Node	Node	The output node.

Note

• The output node is the node that immediately precedes the sink nodes

sink: Node property

Retrieves the artificial sink node of the graph.

Returns:

Name	Type	Description
Node	Node	The sink node.

relay_expr_type: str property

Gets the type of the Relay expression represented by the graph.

Returns:

Name	Type	Description
str	str	The type of the Relay expression.

mod: Relay.IRModule.obj property

Creates the Relay IRModule encoded by the graph.

Returns:

Type	Description
obj	Relay.IRModule.obj: The represented Relay IRModule.

typed_mod: Relay.IRModule.obj property

Creates the Relay IRModule encoded by the graph with typing.

Returns:

Type	Description
obj	Relay.IRModule.obj: The typed Relay IRModule.

Note

• This is can be used as a 'validation' of expression correctness. An error will be thrown for invalid expressions.

operators: Dict[str, int] property

Retrieves a dictionary of operators in the graph and their usage counts.

Returns:

Type	Description
Dict[str, int]	Dict[str, int]: A mapping of operator names to their usage counts.

find(*args, **kwargs) -> Node

Finds a single node in the graph using igraph.Graph.vs.find().

Parameters:

Name	Type	Description	Default
*args		Positional arguments for igraph.Graph.vs.find().	()
**kwargs		Keyword arguments for igraph.Graph.vs.find().	{}

Returns:

Name	Type	Description
Node	Node	The found node.

Note

• This method is direct access to the underlying igraph method, so API matches it directly, please reference the igraph documentation.

• If using lambda functions, the functions are expected to interact with igraph.Vertex objects, not Node objects.

• This method returns a Forge Node instance

select(*args, **kwargs) -> List[Node]

Selects multiple nodes in the graph using igraph.Graph.vs.select().

Parameters:

Name	Type	Description	Default
*args		Positional arguments for igraph.Graph.vs.select().	()
**kwargs		Keyword arguments for igraph.Graph.vs.select().	{}

Returns:

Type	Description
List[Node]	List[Node]: The selected nodes.

Note

• This method is direct access to the underlying igraph method, so API matches it directly, please reference the igraph documentation.

• If using lambda functions, the functions are expected to interact with igraph.Vertex objects, not Node objects.

• This method returns a Forge Node instance

copy() -> Graph

Creates a deep copy of the graph.

Returns:

Name	Type	Description
Graph	Graph	A deep copy of the current graph instance.

get_inference_function(root: Optional[Union[str, Node, igraph.Vertex]] = None, target: str = 'llvm') -> Callable

Generates an inference function for the graph.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node for inference. Defaults to None (i.e. the sink node).	None
target	str	The target for inference (e.g., "llvm"). Defaults to "llvm".	'llvm'

Returns:

Name	Type	Description
Callable	Callable	A callable function for inference.

graft_relay_expr(relay_expr: Relay.Node.obj, target_names: List[str], target_argidxs: List[int], *, root_name: Optional[str] = None) -> str

Grafts a Relay expression onto the graph.

Parameters:

Name	Type	Description	Default
relay_expr	obj	The Relay expression to graft.	required
target_names	List[str]	Names of the target nodes in the graph.	required
target_argidxs	List[int]	Argument indices for the target nodes.	required
root_name	Optional[str]	Optional custom name for the root of the grafted expression. If None, a random node name will be generated. Defaults to None.	None

Returns:

Name	Type	Description
str	str	The name of the grafted root node.

dfs_iter(root: Optional[Union[str, Node, igraph.Vertex]] = None, in_order: bool = True) -> Iterator

Iterates over the graph using depth-first search (DFS) from some root node.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node to start the DFS from. If None, the sink node is used as the root.	None
in_order	bool	Whether to perform an in-order DFS traversal. Defaults to True.	True

Returns:

Name	Type	Description
Iterator	Iterator	An iterator over the nodes in DFS order.

get_relay_mod(root: Optional[Union[str, Node, igraph.Vertex]] = None, typed: bool = True, global_vars: Optional[Dict[str, Relay.GlobalVar.obj]] = None) -> Relay.IRModule.obj

Converts the graph rooted at some node into a Relay IRModule.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node to start from. If None, the sink node is used. Defaults to None.	None
typed	bool	Whether to produce a typed Relay IRModule. Defaults to True.	True
global_vars	Optional[Dict[str, obj]]	A dictionary of global variables to include. Defaults to None.	None

Returns:

Type	Description
obj	Relay.IRModule.obj: The corresponding Relay IRModule.

get_relay_func(root: Optional[Union[str, Node, igraph.Vertex]] = None, typed: bool = True, global_vars: Optional[Dict[str, Relay.GlobalVar.obj]] = None) -> Relay.Function.obj

Converts the graph rooted at some node into a Relay Function.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node to start from. If None, the sink node is used. Defaults to None.	None
typed	bool	Whether to produce a typed Relay Function. Defaults to True.	True
global_vars	Optional[Dict[str, obj]]	A dictionary of global variables to include. Defaults to None.	None

Returns:

Type	Description
obj	Relay.Function.obj: The corresponding Relay Function.

get_relay_expr(root: Optional[Union[str, Node, igraph.Vertex]] = None, typed: bool = True, global_vars: Optional[Dict[str, Relay.GlobalVar.obj]] = None) -> Relay.Node.obj

Converts the graph rooted at some node into a Relay expression.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node to start from. If None, the sink node is used. Defaults to None.	None
typed	bool	Whether to produce a typed Relay expression. Defaults to True.	True
global_vars	Optional[Dict[str, obj]]	A dictionary of global variables to include. Defaults to None.	None

Returns:

Type	Description
obj	Relay.Node.obj: The corresponding Relay expression.

get_unbound_var_nodes(root: Optional[Union[str, Node, igraph.Vertex]] = None, include_inputs: bool = True) -> List[Node]

Retrieves unbound variable nodes in the graph.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node to start from. If None, the sink node is used. Defaults to None.	None
include_inputs	bool	Whether to include input nodes in the result. Defaults to True.	True

Returns:

Type	Description
List[Node]	List[Node]: A list of unbound variable nodes.

get_bound_var_nodes(root: Optional[Union[str, Node, igraph.Vertex]] = None) -> List[Node]

Retrieves bound variable nodes in the graph.

Parameters:

Name	Type	Description	Default
root	Optional[Union[str, Node, Vertex]]	The root node to start from. If None, the sink node is used. Defaults to None.	None

Returns:

Type	Description
List[Node]	List[Node]: A list of bound variable nodes.

reload()

Reloads the graph to restore its original state.

This function resets the graph to its initial state, restoring the original igraph bytes.

__iter__() -> Iterator

Iterates over all nodes in the graph in DFS from the sink.

Returns:

Name	Type	Description
Iterator	Iterator	An iterator over the nodes in the graph.

__eq__(other) -> bool

Checks structural equality between two Graph instances.

Parameters:

Name	Type	Description	Default
other	Graph	The other graph to compare with.	required

Returns:

Name	Type	Description
bool	bool	True if the graphs are equal, False otherwise.

__hash__() -> int

Computes a structural hash value for the graph.

Returns:

Name	Type	Description
int	int	The hash value of the graph.

__repr__() -> str

Generates a string representation of the graph.

Returns:

Name	Type	Description
str	str	A string describing the graph.

__getstate__() -> dict

Serializes the graph state for pickling.

Returns:

Name	Type	Description
dict	dict	The serialized state of the graph.

__setstate__(state) -> None

Restores the graph state from a serialized representation.

Parameters:

Name	Type	Description	Default
state	dict	The serialized state to restore.	required

_init_node(vertex: igraph.Vertex) -> Node

Initializes a Node instance from an igraph.Vertex.

Parameters:

Name	Type	Description	Default
vertex	Vertex	The vertex to initialize a Node from.	required

Returns:

Name	Type	Description
Node	Node	The initialized Node.

_init_nodes(vertices: Union[Iterable[igraph.Vertex], igraph.VertexSeq]) -> List[Node]

Initializes multiple Node instances from igraph vertices.

Parameters:

Name	Type	Description	Default
vertices	Union[Iterable[Vertex], VertexSeq]	The vertices to initialize Nodes from.	required

Returns:

Type	Description
List[Node]	List[Node]: A list of initialized Nodes.

_get_ivertex(node: Union[str, Node, igraph.Vertex]) -> igraph.Vertex

Retrieves the corresponding igraph.Vertex for a given node.

Parameters:

Name	Type	Description	Default
node	Union[str, Node, Vertex]	The node to retrieve the vertex for.	required

Returns:

Type	Description
Vertex	igraph.Vertex: The corresponding igraph.Vertex.