{-# LANGUAGE UnicodeSyntax, FlexibleContexts #-}
module GraphRewriting.Layout.Coulomb where
import Data.View
import Data.Functor ()
import GraphRewriting.Graph.Types
import GraphRewriting.Graph.Read
import GraphRewriting.Pattern ()
import GraphRewriting.Layout.Position
import GraphRewriting.Layout.Force
coulombForce ∷ View Position n ⇒ Node -> WithGraph n Force
coulombForce node = do
n ← examine position <$> readNode node
ns ← fmap (map $ examine position) (mapM readNode =<< readNodeList)
return $ fsum [repulsion n' n | n' ← ns]