core/Validate.php
public static function validRule(array $input = [], array $ruleMap = [], string &$errors = '')
    {
        $tempErrors = [];
        $result = self::validRules($input, $ruleMap, $tempErrors, true);
        if (!$result) {
            $errors = current($tempErrors);
            return false;
        }
        return true;
    }
public static function validRule(array $input = [], array $ruleMap = [], string &$errors = '')
    {
        $tempErrors = [];
        $result = self::validRules($input, $ruleMap, $tempErrors, true);
        if (!$result) {
            $errors = current($tempErrors);
            return false;
        }
        return true;
    }
验证返回当个错误
@param array $input
@param array $ruleMap
@param string $errors
@return bool