ifthenelse: if elsif(s?) else(?) endif { ... }

##</code><code>##

ifthenelse: if elsif(s?) else(?) endif {
   $return = 'NIL';
   for (my $i = 1; $i < @item; $i++)
   {
      print " iftest: $i '" . $item[$i] . "'\n";
      if ($item[$i] ne 'NIL') {  # Always true for $item[2].
         $return = $item[$i];    # Always an array ref for $item[2].
         last;                   # Always gets here for $item[2].
      }
   }

   ...
} 

##</code><code>##

expr      : if
            {
               # I doubt this should be in the grammar.
               $return = evaluate($main::c_v, $item[1]);
            }

if        : /if/i expr /then/i expr if_(?)
            { [ if => @item[2, 4, 5] ] }

if_       : elsif { $item[1] }
          | else  { $item[1] }

elsif     : /elsif/i expr /then/i expr if_
            { [ if => @item[2, 4, 5] ] }

else      : /else/i expr { $item[2] }