paper <ulink url="http://research.microsoft.com/~simonpj/papers/list-comp">
Comprehensive comprehensions: comprehensions with "order by" and "group by"</ulink>,
except that the syntax we use differs slightly from the paper.</para>
+<para>The extension is enabled with the flag <option>-XTransformListComp</option>.</para>
<para>Here is an example:
<programlisting>
employees = [ ("Simon", "MS", 80)
<itemizedlist>
<listitem><para> an expression; the spliced expression must
have type <literal>Q Exp</literal></para></listitem>
+ <listitem><para> an type; the spliced expression must
+ have type <literal>Q Typ</literal></para></listitem>
<listitem><para> a list of top-level declarations; the spliced expression must have type <literal>Q [Dec]</literal></para></listitem>
</itemizedlist>
</para>
(Compared to the original paper, there are many differences of detail.
The syntax for a declaration splice uses "<literal>$</literal>" not "<literal>splice</literal>".
The type of the enclosed expression must be <literal>Q [Dec]</literal>, not <literal>[Q Dec]</literal>.
-Type splices are not implemented, and neither are pattern splices or quotations.
+Pattern splices and quotations are not implemented.)
</sect2>