tree-sitter-dot.ebnf

//
// From tree-sitter-dot/src/grammar.json
//
//
// EBNF to generate railroad diagram at 
//      (IPV6) https://www.bottlecaps.de/rr/ui
//      (IPV4) https://rr.red-dove.com/ui
//

source_file ::=
	 [sS][tT][rR][iI][cC][tT]? ( [gG][rR][aA][pP][hH] | [dD][iI][gG][rR][aA][pP][hH] ) id? block

block ::=
	 '{' stmt_list? '}'

stmt_list ::=
	 ( _stmt ';'? )+

_stmt ::=
	 subgraph
	| node_stmt
	| edge_stmt
	| attr_stmt
	| attribute

subgraph ::=
	 ( [sS][uU][bB][gG][rR][aA][pP][hH] id? )? block

node_stmt ::=
	 node_id attr_list?

edge_stmt ::=
	 ( node_id | subgraph ) ( edgeop ( node_id | subgraph ) )+ attr_list?

attr_stmt ::=
	 ( [gG][rR][aA][pP][hH] | [nN][oO][dD][eE] | [eE][dD][gG][eE] ) attr_list

node_id ::=
	 id port?

port ::=
	 ':' id ( ':' id )?

attr_list ::=
	 ( '[' _a_list? ']' )+

_a_list ::=
	 ( attribute ( ';' | ',' )? )+

attribute ::=
	 id '=' id

id ::=
	 identifier
	| number_literal
	| html_string
	| string_literal ( '+' string_literal )*

identifier ::=
	 [_\p{XID_Start}][_\p{XID_Continue}]*

number_literal ::=
	 '-'?('.'[0-9]+|[0-9]+('.'[0-9]*)?)

string_literal ::=
	 '"'  ([^"\]+|'\.')*'"'

html_string ::=
	 '<' _html_internal? '>'

_html_internal ::=
	 ( [^<>]+ | '<' _html_internal? '>' )+

edgeop ::=
	 '->'
	| '--'

comment ::=
	 ( '//' '.'* | '/*' [^*]*'\'*+([^/*][^*]*'\'*+)* '/' )

preproc ::=
	 '#' '.'*