title: Character vector using tidyr
body: <p>I have a dataframe:</p>
  
  <pre><code>free_text
  "Lead Software Engineer Who We Are: CareerBuilder is the global leader in human capital solutions as we help people target and attract their most important asset - their people. From candidate sourcing solutions, to comprehensive workforce data, to software that streamlines your recruiting process, our focus is always about making your recruitment strategy simple, fast and effective. Are you an experienced software engineer looking to take the next step to leadership? Would you like to lead a team of agile software developers? If so, then we have an immediate need for a self-motivated software engineering lead to join the Candidate Data Processing team in our Norcross, Georgia office. The Candidate Data Processing team is responsible for processing and enriching millions of candidate profiles. We use the Amazon AWS ecosystem as well as our own in-house platform to enhance, normalize, and index candidate profiles from a variety of sources. Our projects require scalable solutions with continuous availability. CareerBuilder engineers participate in every phase of the software development lifecycle and are encouraged to have vision beyond the technical aspects of a project. This position requires knowledge in the theory and practical application of object-oriented design and programming. Prior leadership experience and experience with databases and cloud-computing technologies are desired. Your primary responsibilities as an Engineering Lead will be split between management and technical contributions. You will work with an agile project manager and a product owner to establish objectives and results, and you will lead a team of 3 to 5 software engineers to meet those objectives in a sustainable process. Some of the technologies your team will be using include: AWS (Lambda, SNS, S3, EC2, SQS, DynamoDB, etc.) Java or .net (Java, C#, VB.Net) Unit testing (Junit, MSTest, Moq) Relational databases (SQL) Web services (REST APIs, JSON, RestSharp) Git/github Linux (bash, cron) Job Requirements What we need from you: A passion for technology and bringing your visions to reality through code and leveraging state of the art technologies As a lead, you will take ownership of issues and challenges and will also be a proactive and effective communicator; this role requires successful verbal and written communication to many different audiences inside and outside of Careerbuilder Demonstrated ability to earn your teammates' trust and respect through clear, honest, and helpful communication We prefer you to have proven leadership experience, but also be a hands on, passionate coder BS in Computer Science or related field (preferred but not required) What you will receive: When you're focused on the goal, not the path - you can be more flexible, and that translates into more productive and satisfied employees. From flexible hours to volunteering during work hours to diverse education opportunities, CareerBuilder.com is committed to helping employees strike a balance. Training that positions you to continuously grow with ongoing learning and development courses; we never stop investing in our people. Summer Hours! Enjoy 1/2 day paid Fridays during Summer Hours Quarterly 24 hour Hackathons and bi-weekly personal development time to learn new skills Paid volunteer time and coordinated opportunities to give back to the community Bagel Fridays! Casual Dress Code and laid back environment; don't worry about buying new suits and dry cleaning bills! Comprehensive Medical, Dental &amp; Vision Programs Education Reimbursement Program allowing up to $5k per year towards completion of a Bachelor's and non-MBA graduate degree, and up to $10K per year towards completion of an MBA! No strings attached! $400 Annual Reimbursement for Wellness Activities, including your gym membership! 401(k) Program with Strong Employer Match and 2 year vesting schedule! Five Star Company Paid Trips for top performers, pack your bags and get ready to experience luxury! CareerBuilder, LLC is proud to be an Equal Opportunity Employer. Applicants are considered for all positions without regard to race, color, religion, sex, national origin, age, disability, sexual orientation, ancestry, marital or veteran status."
  "Quality Engineer TSS is currently seeking Quality Engineer for Industrial Manufacturer in the London, KY area. Qualified candidates must have experience in Quality Engineering or related degree. Job Requirements Directs sampling inspection, and testing of produced/received parts, components and materials to determine conformance to standards. Host customers for audits, react to customer complaints, follow through on all sorting and rework of suspect parts. Control of the product sorting/hold areas of the facility. Responsible for directing, instructing and organizing the work of parts sort area. Must follow-up with efficiency, effectiveness and safety of those assigned to work the area. Provides training and completes documentation of all quality training provided to Company employees and forwarding that paperwork to the appropriate individuals (Supervisors, Engineering, Human Resources, etc.). Develop PPAP documentation for specific products; including Quality Control Plans, Flowcharts, FMEA’s, Inspection Reports, measurement/calculations coordination and PSW. Acts as Internal Auditor Coordinator and oversees the maintenance of all TS 16949 documentation. Applies statistical process control (SPC) methods for analyzing data to evaluate the current process and process changes. Works with supervisors and other responsible persons on determining root cause and developing corrective actions for all internal quality concerns. Participate in APQP for specific programs. Communicate with the customer as necessary to ensure all issues around assigned programs are resolved in a timely manner. Respond to customer corrective Action Requests. Develop gauging requirements for assigned programs. Monitor process capability to ensure required standards are maintained. Participate in Continuous Improvement programs. Perform workstation audits on assigned programs. Perform vendor quality audits as required. Prepares and presents technical and program information to team members and management. Accepts responsibility for subordinates?activities; Solicits and applies customer feedback (internal and external); Fosters quality focus in others. Provides computerized status report describing progress and concerns related to inspection activities, nonconforming items, and/or other items related to the quality of the process, material, or product. Reviews quality trends, tracks the root cause of problems, and coordinates correction actions. Provides input and recommendations to management on process of procedural system improvements, such as configuration management and operations functions. Work with technicians to ensure products are measured correctly and all data is compiled for on-time PPAP submissions. Will document and review supplier quality issues to the quality files daily, and communicate any needed Corrective Actions or plans from the suppliers. Formulates contingency plans, reviews control plans and FMEAs and makes necessary updates to the database as needed. Responsibilities include training; assigning and directing work of temporary re-work employees. All other duties as assigned. Training: TS 16949 Documentation:  APQP, PPAP, FMEA, MSA Internal Auditing Education Requirements: College degree or equivalent experience as determined by the Quality Manager. Skills: To perform this job successfully, an individual must be able to perform each essential job functions satisfactory. The duties and responsibilities listed above are representative of the knowledge, skill and/or ability required for the position. Excellent verbal and written skills: Proficient in computer software including Word, Excel, Access: Strong leadership skills: Good problem solving skills; Communicate well with others at all levels. Experience: To perform this position successfully, an individual should have a minimum of three (3) years in related field.  "
  </code></pre>
  
  <p>An I try to test this code:</p>
  
  <pre><code>library(tidytext)
  library(stringr)
  
  reg &lt;- "([^A-Za-z_\\d#@']|'(?![A-Za-z_\\d#@]))"
  tidy_df &lt;- df %&gt;% 
    filter(!str_detect(text, "^RT")) %&gt;%
    mutate(text = str_replace_all(text, 
                                  "https://t.co/[A-Za-z\\d]+|http://[A-Za-z\\d]+|&amp;amp;|&amp;lt;|&amp;gt;|RT|https", 
                                  "")) %&gt;%
    unnest_tokens(word, text, token = "regex", pattern = reg) %&gt;%
    filter(!word %in% stop_words$word,
           str_detect(word, "[a-z]"))
  </code></pre>
  
  <p>But I receive this error:</p>
  
  <pre><code>Error in stri_detect_regex(string, pattern, opts_regex = opts(pattern)) : 
    argument `str` should be a character vector (or an object coercible to)
  </code></pre>
  
  <p>Is there any problem with the input data and this error happens? What can I do to fix it?</p>