Instaparse grammar for dot/graphviz. Incomplete.

grammar.clj

;; original spec https://graphviz.org/doc/info/lang.html
;; this is only a partial implementation

(def grammar "
    G = 'digraph' <WS> graph-name <WS*> block <WS*>

    <ws> = <#'[\\s\\t]+'>           (* whitespace *)
    <WS> = <#'[\\s\\t\\n\\r]+'>   (* multiline whitespace, graphviz is very newline tolerant *)

    <string-q> = <'\"'> #'[^\"]*' <'\"'>
    <string-uq> = #'[a-zA-Z_][a-zA-Z_0-9]+'
    <string> = string-q | string-uq

    block = <'{'> WS* stmt-list WS* <'}'>

    graph-name = string
    node = string

    node-from = node
    node-to = node
    arrow = '->'

    propName = string
    propValue = string
    prop = propName <'='> propValue
    propList =  propList? prop <ws*>
    props = <'['> propList? <']'>

    nodeSpec = <WS*> node <WS*> props?
    edgeSpec = <WS*> node-from <WS*> <arrow> <WS*> node-to <WS*> props?

    stmt-list = stmt-list? stmt
    <stmt> = nodeSpec | edgeSpec
   ")