Color epsilon edges blue in dot file

src/Search/Dot.hs

@@ -3,6 +3,7 @@
 -- TODO Document
 module Search.Dot (graph2dot) where
 
+import           Compare.SSEGraph
 import           Data.Monoid
 
 import qualified Data.Graph.Inductive as G
@@ -36,4 +37,6 @@ dotEdges = foldMap formatEdge . G.labEdges . graph
   where
     formatEdge (from, to, label) =
          B.fromString (show from) <> " -> " <> B.fromString (show to)
-      <> " [label=\"" <> B.fromText label <> "\"];\n"
+      <> " [label=\"" <> B.fromText label <> "\", color=" <> color label <> "];\n"
+    color label = if isEpsilon $ SSEEdgeLabel label then "blue" else "black"
+