{
tokens=[number="regexp:\d+" comma="," paren1="(" paren2=")"]
}
list ::= "(" items? ")" {pin=1} // or {pin="("}
private items ::= [!")" item (',' item) * ] {pin(".*")=1}
item ::= number {recoverWhile=item_recover}
private item_recover ::= !(")" | ",")