d stdlib <code>io</code> modules designed
   to work with iterators as defined by the <code>llists</code> module.</p>
  
   <p>All iterators created by this module work by side effect, making   
them impure. As such, they should only be evaluated once.</p>
  
   As there is no guarantee that an iterator will be completely
   evaluated, this module expects the lifecycle of the opened file
   process to be managed by the caller.
<h2><a name="index">Function Index</a></h2>
<table width="100%" border="1" cellsp