| (* https://bottlecaps.de/rr/ui *) | |
| Definition | |
| ::= PropertyName ( '=' Value )? ( ',' PropertyName ( '=' Value )? )* | |
| Query ::= PropertyQuery ( ',' PropertyQuery )* | |
| PropertyQuery ::= '-' PropertyName | |
| | '?'? ( PropertyName (( '=' | '!=' ) Value)?) | |
| Value ::= NumberLiteral | |
| | StringLiteral | |
| StringLiteral ::= QuotedString | UnquotedString | |
| QuotedString ::= '"' [^"]* '"' | |
| | "'" [^']* "'" | |
| UnquotedString ::= [^{space},]+ | |
| NumberLiteral | |
| ::= '0' ( [0-7]* | 'x' [0-9A-Fa-f]+ ) | |
| | '-'? [1-9] [0-9]+ | |
| PropertyName | |
| ::= [A-Z] [A-Z0-9_]* ( '.' [A-Z] [A-Z0-9_]* )* |