Edge

class understand.Edge

Bases: object

Graph plugin edge object

An edge in a graph. Edges are created from Graph objects with edge. Graphviz attributes can be set. Use sync to associate entities, references, or locations with the edge.

Edge objects are hashable and compare equal when they refer to the same underlying Graphviz edge.

Methods Summary

attributes	Return Graphviz attributes on this edge.
head	Return the head (destination) node of this directed edge.
set	Set edge attribute.
sync	Sync edge to a reference, entities, or file location.
synced_data	Return this edge's current sync data.
tail	Return the tail (source) node of this directed edge.

Methods Documentation

attributes() → dict[str, str]

Return Graphviz attributes on this edge.

Return type:

dict[str, str]

head() → understand.Node

Return the head (destination) node of this directed edge.

Return type:

understand.Node

set(name, value) → None

Set edge attribute.

Parameters:

• name (str) – the attribute name

• value (str) – the attribute value

Return type:

None

Raises:

RuntimeError – on read-only edges from graphs returned by draw (raw graph format)

Refer to Graphviz for available attributes.

sync(ref) → None

sync(arch) → None

sync(ent) → None

sync(ent, comparison_ent) → None

sync(file, line=0, column=0) → None

Sync edge to a reference, entities, or file location.

Parameters:

• ref (understand.Ref) – a reference to sync

• arch (understand.Arch) – an architecture to sync

• ent (understand.Ent) – an entity to sync

• comparison_ent (understand.Ent or None) – an entity from the comparison database

• file (understand.Ent or str) – a file entity or file path

• line (int or None) – optional, a line number

• column (int or None) – optional, a column number

Return type:

None

Raises:

RuntimeError – on read-only graphs returned by draw (raw graph format)

Line and column numbers are 1-based.

For entity comparison, ent or comparison_ent may be None to show added/removed entities.

synced_data() → object

Return this edge’s current sync data.

Return type:

understand.Ref or understand.Arch or understand.Ent or tuple[understand.Ent | None, understand.Ent | None] or dict[str, str | int | understand.Ent] or list[understand.Ref] or None

Returns:

sync data currently associated with this object

Locations are returned as dictionaries with a “file” key and optional keys: “entity”, “line”, “column”, “end_line”, and “end_column”. Line and column numbers are 1-based.

Entity comparisons are returned as a tuple with left and right entities. Either entity may be None, usually representing an added/removed entity.

Built-in graphs have more sync types than supported from plugins. Specifically, locations can have end_line and end_column (Control Flow graphs are an example) and edges often sync a list of references.

tail() → understand.Node

Return the tail (source) node of this directed edge.

Return type:

understand.Node