puppet.ebnf

# Puppet EBNF (kind of)
# Try with: http://www.bottlecaps.de/rr/ui

ACTOR              ::= 'actor' ( '(' PARAMS ')')? ('inherits' NAME)?
                               '{'
                                (QUEUE | INBOX | ACTION | SEQUENCE | PARALLEL | FUNCTION | STATE | CONSTANT | LOCAL_TYPE)* 
                               '}'

SEQUENCE      ::= 'sequence' '{' (ACTION | SEQUENCE | PARALLEL)* '}'
PARALLEL        ::= 'parallel' '{' (ACTION | SEQUENCE | PARALLEL)* '}'

ACTION            ::= 'action' NAME ('{' INPUT* OUTPUT* '}')?
INPUT               ::= ('!!' ASSIGNMENTS?  | ASSIGNMENTS ) '<-' (EXPRESSION | 'state') ('where' EXPRESSION)?
ASSIGNMENTS ::= VARIABLE | '_'  | '[' ASSIGNMENTS (',' ASSIGNMENTS)* ','?  ']' | '(' ASSIGNMENTS (',' ASSIGNMENTS)* ','? ')'


FUNCTION        ::= 'function' '(' PARAMS ')' '{' EXPRESSION* '}'
STATE                ::= WORD ( ',' WORD)*
QUEUE             ::= VISIBILITY 'queue' TYPE NAME ('{' ( (
                                    'capacity'
                                  | 'ttl'
                                  | 'entries'
                                  | 'schedule'
                                  | 'latched'
                                  | 'replace'
                                  )
                                            '=>' EXPRESSION)* '}')?

INBOX               ::= VISIBILITY 'queue' TYPE NAME ('{' ( (
                                    'capacity'
                                  | 'ttl'
                                  | 'entries'
                                  | 'schedule'
                                  | 'latched'
                                  | 'replace'
                                  )
                                            '=>' EXPRESSION)* '}')?

PARAMS             ::= TYPE? '*'? VARIABLE ('=' EXPRESSION)?  (',' TYPE? '*'? VARIABLE ('=' EXPRESSION)?)* ','?
CONSTANT         ::= VARIABLE '=' EXPRESSION
LOCAL_TYPE     ::= 'type' TYPE_NAME '=' TYPE_EXPRESSION
VARIABLE           ::= '$' NAME
NAME                 ::= [a-z][a-z0-9A-Z]*
IGNORED           ::= [_]
VISIBILITY          ::= 'private' | 'protected' | 'public'

EXPRESSION    ::= EXPRESSION ('+' | '-' | '*' | '/' | '%' | '.' | 'and' | 'or' | '==' | '!=' | '=~' | '!~'  | '<' | '>' | '>=' | '<=' ) EXPRESSION 
                          |     EXPRESSION '[' EXPRESSION (',' EXPRESSION)* ','?']'
                          | '-' EXPRESSION
                          | '(' EXPRESSION ')'
                          | 'not' EXPRESSION
                          | 'if' EXPRESSION '{' EXPRESSIONS? '}'  ELSE_IF* ELSE?
                          | 'unless' EXPRESSION '{' EXPRESSIONS? '}'  ELSE?
                          | 'case' EXPRESSION '{'  ((EXPRESSION (',' EXPRESSION)*) ':' '{' EXPRESSIONS? '}' )* '}'
                          | EXPRESSION '?' '{' (EXPRESSION '=>' EXPRESSION (',' EXPRESSION '=>' EXPRESSION)* ) '}'
                          | 'default' | 'undef'
                          | DQ_STRING | HEREDOC
                          | LITERAL

LITERAL ::= INTEGER | FLOAT | SQ_STRING | BOOLEAN | REGEXP
BOOLEAN ::= 'false' | 'true'
INTEGER ::= '0' [0-7]* | ('0x' | '0X') [0-9a-fA-F]* | [1-9][0-9]*
FLOAT ::= [0-9]+ '.' [0-9]+ (('e'|'E') ('+'|'-') [0-9]+)
SQ_STRING ::= ['] '<chars and escapes>' [']
DQ_STRING ::= ["] '<chars, escapes, and interpolation>' ["]
HEREDOC ::= '@(' '<heredoc-header-syntax>' ')'
REGEXP ::= '/' '<regexp-syntax>' '/'
           
EXPRESSIONS ::= EXPRESSION (';'? EXPRESSION)*

ELSIF             ::=  'elsif' EXPRESSION '{' EXPRESSIONS? '}'

ELSE              ::= 'else' '{' EXPRESSIONS? '}'