de> evaluates to failure</li><li><code>while_</code> returns <code>false</code></li><li><code>sep_by</code> evaluates to failure <b>Note</b> <code>while_</code> does not consume input.</li></ul><p>Examples</p><p>Default behaviour.</p><pre><code>module P = Reparse.String

;;
let p = P.(take_while ~while_:(is_not (char 'b')) (char 'a')) in
let v = P.parse_string p &quot;aab&quot; in
v = [ 'a'; 'a' ]</code></pre><p>Specify <code>sep_by</code>.</p><pre><code>module P = Reparse.String

;;
let p =
  P.(
    take_