+{-# OPTIONS -fno-warn-missing-signatures #-}
-- | Basic operations on graphs.
--
--- TODO: refine coalescing crieteria
-
-{-# OPTIONS -fno-warn-missing-signatures #-}
module GraphOps (
addNode, delNode, getNode, lookupNode, modNode,
-- less colorable (aggressive coalescing)
-> Triv k cls color
-> Graph k cls color
- -> (Graph k cls color, [(k, k)])
+ -> ( Graph k cls color
+ , [(k, k)]) -- pairs of nodes that were coalesced, in the order that the
+ -- coalescing was applied.
coalesceGraph aggressive triv graph
= coalesceGraph' aggressive triv graph []
-- keep running until there are no more coalesces can be found
in case catMaybes mPairs of
- [] -> (graph', kkPairsAcc)
- pairs -> coalesceGraph' aggressive triv graph' (pairs ++ kkPairsAcc)
+ [] -> (graph', reverse kkPairsAcc)
+ pairs -> coalesceGraph' aggressive triv graph' (reverse pairs ++ kkPairsAcc)
-- | Coalesce this pair of nodes unconditionally / agressively.