code: func (tok Token) Precedence() int {
  	switch tok {
  	case OR:
  		return 1
  	case AND:
  		return 2
  	case EQ, NEQ, EQREGEX, NEQREGEX, LT, LTE, GT, GTE:
  		return 3
  	case ADD, SUB, BITWISE_OR, BITWISE_XOR:
  		return 4
  	case MUL, DIV, MOD, BITWISE_AND:
  		return 5
  	}
  	return 0
  }
docs: // Precedence returns the operator precedence of the binary operator token.