#dot API reference

Graphviz DOT graph description: build a graph of nodes and edges with attributes and render it to .dot text for an external Graphviz tool to lay out and draw (dot -Tsvg graph.dot > graph.svg). Pure Jennifer - no Go, no system library, both binaries - it emits the text description only; graph layout is Graphviz's job and is deliberately not reimplemented. Value semantics throughout: every builder returns a fresh Graph, so the graph you pass in is never mutated.

Import with import "dot.j" as dot;. See the dot guide for prose and examples.

#Functions

#dot.digraph(name as string)

A new, empty directed graph. Renders as digraph with a -> b edges.

Parameters

• name {string} - the graph name

Returns {Graph} - an empty directed graph

#dot.edge(g as Graph, src as string, dst as string)

Add a bare edge between two node ids.

Parameters

• g {Graph} - the graph
• src {string} - the source node id
• dst {string} - the destination node id

Returns {Graph} - a copy with the edge appended

#dot.edgeAttr(g as Graph, key as string, value as string)

Set a default edge attribute, rendered once as edge [ ... ] before the edges - so every edge inherits, e.g. color = gray.

Parameters

• g {Graph} - the graph
• key {string} - the attribute name
• value {string} - the attribute value

Returns {Graph} - a copy with the default set

#dot.edgeWith(g as Graph, src as string, dst as string, attrs as map of string to string)

Add an edge with attributes ({"label": "calls", "style": "dashed"}).

Parameters

• g {Graph} - the graph
• src {string} - the source node id
• dst {string} - the destination node id
• attrs {map of string to string} - the edge's DOT attributes

Returns {Graph} - a copy with the edge appended

#dot.graph(name as string)

A new, empty undirected graph. Renders as graph with a -- b edges.

Parameters

• name {string} - the graph name

Returns {Graph} - an empty undirected graph

#dot.graphAttr(g as Graph, key as string, value as string)

Set a graph-level attribute (rendered as key="value";), e.g. rankdir = LR or a graph label.

Parameters

• g {Graph} - the graph
• key {string} - the attribute name
• value {string} - the attribute value

Returns {Graph} - a copy with the attribute set

#dot.node(g as Graph, id as string)

Add a bare node (no attributes). Adding a node is optional - an id first seen on an edge is created implicitly by Graphviz - but an explicit node carries a label, shape, or colour.

Parameters

• g {Graph} - the graph
• id {string} - the node id

Returns {Graph} - a copy with the node appended

#dot.nodeAttr(g as Graph, key as string, value as string)

Set a default node attribute, rendered once as node [ ... ] before the nodes - so every node inherits, e.g. shape = box.

Parameters

• g {Graph} - the graph
• key {string} - the attribute name
• value {string} - the attribute value

Returns {Graph} - a copy with the default set

#dot.nodeWith(g as Graph, id as string, attrs as map of string to string)

Add a node with attributes ({"label": "Parser", "shape": "box"}).

Parameters

• g {Graph} - the graph
• id {string} - the node id
• attrs {map of string to string} - the node's DOT attributes

Returns {Graph} - a copy with the node appended

#dot.render(g as Graph)

Render the graph to DOT text (a trailing newline included), ready to write to a .dot file or pipe to dot.

Parameters

• g {Graph} - the graph to render

Returns {string} - the DOT source

#Structs

#dot.Edge

A directed or undirected edge between two node ids, with its own attributes.

#dot.Graph

A whole graph: its kind (directed = digraph), name, ordered nodes and edges, and default attribute blocks for the graph, its nodes, and its edges.

#dot.Node

A single graph node: an id (its key in the graph) plus an ordered attribute map (label, shape, color, ...).