4.1.8.3. dg/GraphInterface¶

class DG.Vertex¶

A descriptor of either a vertex in a derivation graph, or a null vertex.

__init__()¶: Constructs a null descriptor.

isNull()¶

Returns:: whether this is a null descriptor or not.
Return type:: bool

id¶

(Read-only) The index of the vertex. It will be in the range \([0, numVertices + numEdges[\).

Type:: int
Raises:: LogicError if it is a null descriptor.

dg¶

(Read-only) The derivation graph the vertex belongs to.

Type:: DG
Raises:: LogicError if it is a null descriptor.

inDegree¶

(Read-only) The in-degree of the vertex, including multiplicity of target multisets.

Type:: int
Raises:: LogicError if it is a null descriptor.

inEdges¶

(Read-only) A range of in-hyperedges for this vertex.

Type:: DG.InEdgeRange
Raises:: LogicError if it is a null descriptor.

outDegree¶

(Read-only) The out-degree of the vertex, including multiplicity of source multisets.

Type:: int
Raises:: LogicError if it is a null descriptor.

outEdges¶

(Read-only) A range of out-hyperedges for this vertex.

Type:: DG.OutEdgeRange
Raises:: LogicError if it is a null descriptor.

graph¶

(Read-only) The graph label of the vertex.

Type:: Graph
Raises:: LogicError if it is a null descriptor.

class DG.HyperEdge¶

A descriptor of either a hyperedge in a derivation graph, or a null edge.

__init__()¶: Constructs a null descriptor.

isNull()¶

Returns:: whether this is a null descriptor or not.
Return type:: bool

id¶

(Read-only) The index of the hyperedge. It will be in the range \([0, numVertices + numEdges[\).

Type:: int
Raises:: LogicError if it is a null descriptor.

dg¶

(Read-only) The derivation graph the edge belongs to.

Type:: DG
Raises:: LogicError if it is a null descriptor.

numSources¶

(Read-only) The number of sources of the hyperedge.

Type:: int

sources¶

(Read-only) The sources of the hyperedge.

Type:: DG.SourceRange
Raises:: LogicError if it is a null descriptor.

numTargets¶

(Read-only) The number of targets of the hyperedge.

Type:: int

targets¶

(Read-only) The targets of the hyperedge.

Type:: DG.TargetRange
Raises:: LogicError if it is a null descriptor.

rules¶

(Read-only) The rules associated with the hyperedge.

Type:: DG.RuleRange
Raises:: LogicError if it is a null descriptor.

inverse¶

(Read-only) A descriptor for the inverse hyperedge of this one, if it exists. Otherwise a null descriptor is returned.

Type:: DG.HyperEdge
Raises:: LogicError if it is a null descriptor.
Raises:: LogicError if not dg.locked.

print(printer=GraphPrinter(), nomatchColour='gray', matchColour='', verbosity=0)¶

Print the derivations represented by the hyperedge. All possible Double-Pushout diagrams are printed.

Parameters:

printer (GraphPrinter) – the printer to use for the figures.
matchColour (str) – the TikZ colour to use for the rule and its image in the bottom span.
verbosity (int) – see dg::DG::HyperEdge::print().

Returns:

A list with file data for each DPO diagram printed. Each element is a pair of filename prefixes, where the first entry is completed by appending _derL, _derK, or _derR. The second entry is completed similarly by appending _derG, _derD, or _derH.

Return type:

list[tuple[str, str]]

Raises:

LogicError if it is a null descriptor.

Raises:

LogicError if it has no rules.