%token <string> FLAG
%token LPAREN RPAREN
%token OR AND
%token NOT
%token EOF
%left OR
%left AND
%nonassoc NOT

%start <Filter.t> filter
%%

filter:
  | f = expr; EOF { f }

expr:
  | f = FLAG                   { Filter.Flag (Config.of_string f) }
  | LPAREN; e = expr; RPAREN   { e }
  | e1 = expr; AND; e2 = expr  { Filter.And (e1, e2) }
  | e1 = expr; OR; e2 = expr   { Filter.Or (e1, e2) }
  | NOT; e = expr              { Filter.Not e }