docs: function(i, query) {
      return  SpahQL.Token.ComparisonOperator.parseAt(i, query) ||
              SpahQL.Token.String.parseAt(i, query) ||
              SpahQL.Token.Numeric.parseAt(i, query) ||
              SpahQL.Token.Boolean.parseAt(i, query) ||
              SpahQL.Token.Set.parseAt(i, query) ||
              SpahQL.Token.SelectionQuery.parseAt(i, query) ||
              null;
    }