title: create list from characters in R tibble
body: <p>I have a tibble with a character column. The character in each row is a set of words like this: &quot;type:mytype,variable:myvariable,variable:myothervariable:asubvariableofthisothervariable&quot;. Things like that. I want to either convert this into columns in my tibble (a column &quot;type&quot;, a column &quot;variable&quot;, and so on; but then I don't really know what to do with my 3rd level words), or convert it to a column list x, so that x has a structure of sublists: x$type, x$variable, x$variable$myothervariable.</p>
  <p>I'm not sure what is the best approach, but also, I don't know how to implement this two approaches that I suggest here. I have to say that I have maximum 3 levels, and more 1st level words than &quot;type&quot; and &quot;variable&quot;.</p>
  <p>Small Reproducible Example:</p>
  <pre><code>df &lt;- tibble()
  df$id&lt;- 1:3
  df$keywords &lt;- c(
    &quot;type:novel,genre:humor:black,year:2010&quot;
    &quot;type:dictionary,language:english,type:bilingual,otherlang:french&quot;
    &quot;type:essay,topic:philosophy:purposeoflife,year:2005&quot;
  )
  
  # expected would be in idea 1: 
  colnames(df)
  # n, keywords, type, genre, year, 
  # language, otherlang, topic
  
  # on idea 2:
  colnames(df)
  # n, keywords, keywords.as.list
  
  </code></pre>