title: Forward fill rows in a r data table
body: <p>I have a large data.table in the format below</p>
  
  <pre><code>Name       Value     1      2     3     4     5 
  A           58       1      NA    NA    NA    NA
  B           47       NA     1     NA    NA    NA
  C           89       NA     NA    1     NA    NA
  D           68       NA     NA    NA    1     NA
  E           75       NA     NA    NA    NA    1
  </code></pre>
  
  <p>I would like to forward rows of the data table to achieve below results. I know how to forward fill columns.</p>
  
  <pre><code>Name       Value     1      2     3     4     5 
  A           58       1      1     1     1     1
  B           47       NA     1     1     1     1
  C           89       NA     NA    1     1     1
  D           68       NA     NA    NA    1     1
  E           75       NA     NA    NA    NA    1  
  
  </code></pre>
  
  <p>Help!</p>