X-Git-Url: http://git.cielonegro.org/gitweb.cgi?p=hs-rrdtool.git;a=blobdiff_plain;f=Data%2FHList%2FGraph.hs;fp=Data%2FHList%2FGraph.hs;h=ee5f613f1d5b4daea8ff4ed47dad0d643d31bb54;hp=0000000000000000000000000000000000000000;hb=c788edcf6744a51cb38795e4f1959d22d10ad071;hpb=2787678974b80d73e91b49b6b7c5469c6eb5ac1e

diff --git a/Data/HList/Graph.hs b/Data/HList/Graph.hs
new file mode 100644
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--- /dev/null
+++ b/Data/HList/Graph.hs
@@ -0,0 +1,33 @@
+{-# LANGUAGE
+  FlexibleContexts,
+  FlexibleInstances,
+  TypeFamilies
+  #-}
+module Data.HList.Graph
+    ( HNodeSet
+    , HNode(..)
+    , HGraph(..)
+    )
+    where
+
+import Data.HList.Prelude
+
+-- HNodeSet
+class    HNodeSet ns
+instance HNodeSet HNil
+instance HNodeSet ns => HNodeSet (HCons n ns)
+
+-- HNode
+class ( HNodeSet (HLinksFrom n)
+      )
+    => HNode n
+    where
+      type HNodeID n
+      type HLinksFrom n
+
+-- HGraph
+class ( HNodeSet (HNodes g)
+      )
+    => HGraph g
+    where
+      type HNodes g