%token BAGS
%token CONTAIN
%token NO
%token OTHER
%token COMMA ","
%token DOT   "."
%token EOF
%token<int>    NUMBER
%token<string> WORD

%start<Day7_syntax.rules> rules

%%

let rules := ~ = list(rule); EOF; <>

let rule := ~ = bag; CONTAIN; ~ = contents; DOT; <>

let contents :=
  | NO; OTHER; BAGS; { [] }
  | ~ = separated_nonempty_list(COMMA, number_bag); <>

let number_bag := n = NUMBER; b = bag; { b, n }

let bag := words = list(WORD); BAGS; { String.concat " " words }