title: Abbreviation of "collapse" in paste?
body: <p>Using the command <code>paste</code> in R, I wanted to use both arguments <code>sep</code> and <code>collapse</code>, but you cannot abbreviate <code>collapse</code> to <code>coll</code> or even <code>collaps</code>.  Yet for other functions partial abbreviation works.</p>
  
  <p>For example:</p>
  
  <pre><code>paste(letters, colla=", ")
  # [1] "a , " "b , " "c , " "d , " "e , " "f , " "g , " "h , " "i , " "j , " "k , " "l , " "m , " "n , " "o , " "p , " "q , " "r , "
  [19] "s , " "t , " "u , " "v , " "w , " "x , " "y , " "z , "
  paste(letters, collapse=", ")
  # [1] "a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z"
  </code></pre>
  
  <p>There are no other arguments to collapse that start with <code>coll</code>, which would interfere with the partial argument matching.  </p>
  
  <p>Why must I type out the entire argument name when calling <code>paste</code>, when I do not have to for other functions?</p>