3 files changed, 31 insertions, 4 deletions
diff --git a/haddock-api/src/Haddock/Backends/Xhtml.hs b/haddock-api/src/Haddock/Backends/Xhtml.hs
index e5e4db3f..fce95814 100644
--- a/haddock-api/src/Haddock/Backends/Xhtml.hs
+++ b/haddock-api/src/Haddock/Backends/Xhtml.hs
@@ -525,7 +525,7 @@ ifaceToHtml maybe_source_url maybe_wiki_url iface unicode qual
   = ppModuleContents qual exports +++
     description +++
     synopsis +++
-    divInterface (maybe_doc_hdr +++ bdy)
+    divInterface (maybe_doc_hdr +++ bdy +++ orphans)
   where
     exports = numberSectionHeadings (ifaceRnExportItems iface)
 
@@ -564,6 +564,9 @@ ifaceToHtml maybe_source_url maybe_wiki_url iface unicode qual
       foldr (+++) noHtml $
         mapMaybe (processExport False linksInfo unicode qual) exports
 
+    orphans = (h1 << "Orphan instances") +++
+      ppOrphanInstances linksInfo (ifaceRnOrphanInstances iface) False unicode qual
+
     linksInfo = (maybe_source_url, maybe_wiki_url)
 
 
diff --git a/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs b/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
index e536ae4b..031b40e5 100644
--- a/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
+++ b/haddock-api/src/Haddock/Backends/Xhtml/Decl.hs
@@ -16,7 +16,7 @@
 module Haddock.Backends.Xhtml.Decl (
   ppDecl,
 
-  ppTyName, ppTyFamHeader, ppTypeApp,
+  ppTyName, ppTyFamHeader, ppTypeApp, ppOrphanInstances,
   tyvarNames
 ) where
 
@@ -548,6 +548,21 @@ ppInstances links origin instances splice unicode qual
         ((ppInstHead links splice unicode qual mdoc origin no inst), loc)
 
 
+ppOrphanInstances :: LinksInfo
+                  -> [DocInstance DocName]
+                  -> Splice -> Unicode -> Qualification
+                  -> Html
+ppOrphanInstances links instances splice unicode qual
+  = subOrphanInstances qual links True (zipWith instDecl [1..] instances)
+  where
+    instOrigin :: InstHead name -> InstOrigin name
+    instOrigin inst = OriginClass (ihdClsName inst)
+
+    instDecl :: Int -> DocInstance DocName -> (SubDecl,Located DocName)
+    instDecl no (inst, mdoc, loc) =
+        ((ppInstHead links splice unicode qual mdoc (instOrigin inst) no inst), loc)
+
+
 ppInstHead :: LinksInfo -> Splice -> Unicode -> Qualification
            -> Maybe (MDoc DocName)
            -> InstOrigin DocName -> Int -> InstHead DocName
diff --git a/haddock-api/src/Haddock/Backends/Xhtml/Layout.hs b/haddock-api/src/Haddock/Backends/Xhtml/Layout.hs
index d624a1d0..b20cd172 100644
--- a/haddock-api/src/Haddock/Backends/Xhtml/Layout.hs
+++ b/haddock-api/src/Haddock/Backends/Xhtml/Layout.hs
@@ -31,7 +31,7 @@ module Haddock.Backends.Xhtml.Layout (
   subConstructors,
   subEquations,
   subFields,
-  subInstances, subInstHead, subInstDetails,
+  subInstances, subOrphanInstances, subInstHead, subInstDetails,
   subMethods,
   subMinimal,
 
@@ -200,7 +200,16 @@ subInstances qual nm lnks splice = maybe noHtml wrap . instTable
     subCaption = paragraph ! collapseControl id_ True "caption" << "Instances"
     id_ = makeAnchorId $ "i:" ++ nm
 
- 
+
+subOrphanInstances :: Qualification
+                   -> LinksInfo -> Bool
+                   -> [(SubDecl,Located DocName)] -> Html
+subOrphanInstances qual lnks splice  = maybe noHtml id . instTable
+  where
+    instTable = fmap (thediv ! collapseSection id_ True [] <<) . subTableSrc qual lnks splice
+    id_ = makeAnchorId $ "orphans"
+
+
 subInstHead :: String -- ^ Instance unique id (for anchor generation)
             -> Html -- ^ Header content (instance name and type)
             -> Html