PEG for GraphViz DOT

file <-

_ graph+

graph:

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

graph <-

'strict'? ('graph' / 'digraph') ID? '{' stmt_list '}'

graph <-

'strict'? ('graph' / 'digraph') ID? '{' stmt_list '}'

graph <-

'strict'? ('graph' / 'digraph') ID? '{' stmt_list '}'

graph <-

('strict' _)? ('graph' / 'digraph') _ ID? '{' _ stmt_list '}' _

stmt_list:

[ stmt [ ';' ] stmt_list ]

stmt_list <-

(stmt ';'? stmt_list)?

stmt_list <-

(stmt ';'? stmt_list)?

stmt_list <-

(stmt ';'?)*

stmt_list <-

(stmt (';' _)?)*

stmt:

node_stmt

stmt <-

node_stmt

stmt <-

attr_stmt

stmt <-

attr_stmt

stmt <-

attr_stmt

| edge_stmt

/ edge_stmt

/ edge_stmt

/ edge_stmt

/ edge_stmt

| attr_stmt

/ attr_stmt

/ subgraph

/ subgraph

/ subgraph

| ID '=' ID

/ ID '=' ID

/ ID '=' ID

/ ID '=' ID

/ ID '=' _ ID

| subgraph

/ subgraph

/ node_stmt

/ node_stmt

/ node_stmt

attr_stmt:

(graph | node | edge) attr_list

attr_stmt <-

('graph' / 'node' / 'edge') attr_list

attr_stmt <-

('graph' / 'node' / 'edge') attr_list

attr_stmt <-

('graph' / 'node' / 'edge') attr_list

attr_stmt <-

('graph' / 'node' / 'edge') _ attr_list

attr_list:

'[' [ a_list ] ']' [ attr_list ]

attr_list <-

'[' a_list? ']' attr_list?

attr_list <-

'[' a_list? ']' attr_list?

attr_list <-

('[' attr* ']')+

attr_list <-

('[' _ attr* ']' _)+

a_list:

ID '=' ID [ (';' | ',') ] [ a_list ]

a_list <-

ID '=' ID [;,]? a_list?

a_list <-

ID '=' ID [;,]? a_list?

a_list <-

(ID '=' ID [;,]?)+

attr <-

ID '=' ID [;,]?

attr <-

ID '=' _ ID ([;,] _)?

edge_stmt:

(node_id | subgraph) edgeRHS [ attr_list ]

edge_stmt <-

(node_id / subgraph) edgeRHS attr_list?

edge_stmt <-

(subgraph / node_id) edgeRHS attr_list?

edge_stmt <-

(subgraph / node_id) edgeRHS attr_list?

edge_stmt <-

(subgraph / node_id) edgeRHS attr_list?

edgeRHS:

edgeop (node_id | subgraph) [ edgeRHS ]

edgeRHS <-

edgeop (node_id / subgraph) edgeRHS?

edgeRHS <-

edgeop (subgraph / node_id) edgeRHS?

edgeRHS <-

(edgeop (subgraph / node_id))+

edgeRHS <-

(edgeop (subgraph / node_id))+

node_stmt:

node_id [ attr_list ]

node_stmt <-

node_id attr_list?

node_stmt <-

node_id attr_list?

node_stmt <-

node_id attr_list?

node_stmt <-

node_id attr_list?

node_id:

ID [ port ]

node_id <-

ID port?

node_id <-

ID port?

node_id <-

ID port? port?

node_id <-

ID port? port?

port:

':' ID [ ':' compass_pt ]

port <-

':' ID (':' compass_pt)?

port <-

':' ID (':' ID)?

port <-

':' ID

port <-

':' _ ID

| ':' compass_pt

/ ':' compass_pt

subgraph:

[ subgraph [ ID ] ] '{' stmt_list '}'

subgraph <-

('subgraph' ID?)? '{' stmt_list '}'

subgraph <-

('subgraph' ID?)? '{' stmt_list '}'

subgraph <-

('subgraph' ID?)? '{' stmt_list '}'

subgraph <-

('subgraph' _ ID?)? '{' _ stmt_list '}' _

compass_pt:

(n | ne | e | se | s | sw | w | nw | c | _)

compass_pt <-

'n' / 'ne' / 'e' / 'se' / 's' / 'sw' / 'w' / 'nw' / 'c' / '_'

compass_pt <-

'ne' / 'nw' / 'se' / 'sw'/ 's' / 'w' / 'n' / 'e' / 'c' / '_'

edgeop <-

edgeop <-

edgeop <-

('--' / '->') _

ID <-

ID <-

ID <-

HTML

/ QUOTED

/ NUMERAL

/ STRING

HTML <-

'<' (![<>] . / HTML)* '>' _

QUOTED <-

'"' ESCAPED* '"' _ ('+' _ '"' ESCAPED* '"' _)*

ESCAPED <-

ESC_QUOTE

/ ESC_EOL

/ '\\' .

/ !'"' .

ESC_QUOTE <-

'\\"'

ESC_EOL <-

'\\' EOL

NUMERAL <-

'-'? ([0-9]+ ('.' [0-9]*)? / '.' [0-9]+) _

STRING <-

[A-Z_a-z\u0080-\uFFFF] [0-9A-Z_a-z\u0080-\uFFFF]* _

_ <-

([ \t] / EOL / COMMENT)*

COMMENT <-

COMMENT_HASH

/ COMMENT_SLASH

/ COMMENT_BLOCK

COMMENT_HASH <-

'#' (!EOL .)*

COMMENT_SLASH <-

'//' (!EOL .)*

COMMENT_BLOCK <-

'/*' (!'*/' .)* '*/'

EOL <-

'\r\n' / '\n' / '\r'