Graphviz/Dot

A graphviz source start from either graph or digraph. In graph, you need to use -- for edges, while in digraph, use -> instead. An optional strict means there's no duplicated edges (previous will be removed).

Statements are separated by semicolon. Typically there are node stmt, edge stmt, and subgraph to group statements.

graph :: [strict] (graph | digraph) [ID] '{' stmt_list '}'
subgraph :: [subgraph [ID] ] '{' stmt_list '}'

stmt_list :: stmt ';' stmt_list
stmt :: node_stmt | edge_stmt | attr_stmt | ID '=' ID | subgraph

Attributes can be associated with node, edge, graph, subgraph, or cluster of subgraph. It is a list of key=value pairs. The attr_stmt is meant for setting style for the whole subgraph.

attr_stmt :: (graph | node | edge) attr_list
attr_list :: '[' (ID = ID) + ']'

If you only want to apply attr to node, you should write the node_stmt separately, otherwise it will be applied on the edges.

edge_stmt :: (node_id | subgraph) (->|--) (node_id | subgraph) + [attr_list]
node_stmt :: node_id [attr_list]

A subgraph is a cluster, if its name has prefix cluster.

• attribute: https://graphviz.gitlab.io/_pages/doc/info/attrs.html
• Color names: https://graphviz.gitlab.io/_pages/doc/info/colors.html

name	used by (NEC by default)	value
color
fillcolor
fontcolor
fontsize
label
labeldistance	E
labelfontsize	E
style
shape	N

common style:

• solid
• dashed
• dotted
• bold

node style:

• rounded
• diagonals
• filled
• striped
• wedged

Edge style: just common style.

Cluster style

• rounded
• filled
• striped

Node shape (some):

• box
• ellipse
• oval
• circle
• diamond
• plaintext

dot -Tpng -o xxx.png xxx.dot
# automatic generate output filename based on input name
dot -Tpng -O xxx.dot

Popular output format:

• png
• pdf
• svg