<para>The trouble with orphans is that GHC must pro-actively read the interface
files for all orphan modules, just in case their instances or rules
play a role, whether or not the module's interface would otherwise
- be of any use. Other things being equal, avoid orphan modules.</para>
+ be of any use. See <xref linkend="orphan-modules"/> for details.
+ </para>
</listitem>
</varlistentry>
<para>GHC can dump its optimized intermediate code (said to be in “Core” format)
to a file as a side-effect of compilation. Non-GHC back-end tools can read and process Core files; these files have the suffix
- <filename>.hcr</filename>. The Core format is described in <ulink url="http://www.haskell.org/ghc/docs/papers/core.ps.gz">
+ <filename>.hcr</filename>. The Core format is described in <ulink url="../ext-core/core.pdf">
<citetitle>An External Representation for the GHC Core Language</citetitle></ulink>,
and sample tools
for manipulating Core files (in Haskell) are in the GHC source distribution