`dot` - Graphviz DOT graph description

Import with import "dot.j" as dot;. Builds a graph of nodes and edges with attributes and renders it to .dot text for an external Graphviz tool to lay out and draw. Pure Jennifer over strings and lists, so it runs on either binary. It emits the text description only - graph layout is Graphviz's job and is deliberately not reimplemented (drawing a graph is a large algorithm the dot tool exists to do). Every builder returns a fresh Graph, so value semantics hold: the graph you pass in is never mutated.

jennifer

use io;
import "dot.j" as dot;

def g as dot.Graph init dot.digraph("pipeline");
$g = dot.graphAttr($g, "rankdir", "LR");
$g = dot.nodeAttr($g, "shape", "box");
$g = dot.nodeWith($g, "lexer", {"label": "Lexer"});
$g = dot.edgeWith($g, "lexer", "parser", {"label": "tokens"});
io.printf("%s", dot.render($g));

Pipe the rendered text to Graphviz to produce an image:

jennifer run graph.j | dot -Tsvg > graph.svg

Runnable: examples/modules/dot_demo.j.

Surface

Call	Returns	Notes
`dot.digraph(name)`	`Graph`	A new directed graph - renders `digraph`, edges `a -> b`.
`dot.graph(name)`	`Graph`	A new undirected graph - renders `graph`, edges `a -- b`.
`dot.node(g, id)`	`Graph`	Add a bare node (optional - an id first seen on an edge is created implicitly).
`dot.nodeWith(g, id, attrs)`	`Graph`	Add a node with a `map of string to string` of DOT attributes (`{"shape": "box"}`).
`dot.edge(g, src, dst)`	`Graph`	Add a bare edge between two node ids.
`dot.edgeWith(g, src, dst, attrs)`	`Graph`	Add an edge with its own attributes (`{"label": "calls"}`).
`dot.graphAttr(g, key, value)`	`Graph`	Set a graph-level attribute (`rankdir` = LR, a graph `label`, ...).
`dot.nodeAttr(g, key, value)`	`Graph`	Set a default node attribute, rendered once as `node [ ... ]`.
`dot.edgeAttr(g, key, value)`	`Graph`	Set a default edge attribute, rendered once as `edge [ ... ]`.
`dot.render(g)`	`string`	Render the graph to DOT text (with a trailing newline).

Attribute maps keep insertion order, so the rendered attribute list is stable. String values (labels, the graph name, attribute values) are DOT-escaped: a backslash and a double-quote are backslash-escaped, and a literal newline becomes the two-character \n DOT escape - so a label carrying quotes or newlines stays well-formed.

Types

Graph { directed as bool, name as string, nodes as list of Node, edges as list of Edge, graphAttrs as map of string to string, nodeAttrs as map of string to string, edgeAttrs as map of string to string }
Node { id as string, attrs as map of string to string }
Edge { from as string, to as string, attrs as map of string to string }

The fields are public for inspection, but the builders (digraph / graph / node* / edge* / *Attr) are the intended construction path.

#dot - Graphviz DOT graph description

#Surface

#Types

`dot` - Graphviz DOT graph description

Surface

Types