rextra/src/Rextra/Util.hs

56 lines
1.7 KiB
Haskell

{-# LANGUAGE TupleSections #-}
module Rextra.Util
( connectedElements
-- * Renaming
, Rename
, doRename
, getName
, renameSet
, renameMap
, renameKeys
, renameValues
) where
import Control.Monad
import Control.Monad.Trans.State
import qualified Data.Map as Map
import qualified Data.Set as Set
explore :: (Ord n) => (n -> Set.Set n) -> n -> State (Set.Set n) ()
explore trans node = do
visited <- get
unless (node `Set.member` visited) $ do
modify (Set.insert node)
mapM_ (explore trans) . Set.toList $ trans node
connectedElements :: (Ord n) => (n -> Set.Set n) -> Set.Set n -> Set.Set n
connectedElements trans startingNodes =
flip execState Set.empty . mapM (explore trans) $ Set.toList startingNodes
type Rename n = State (Int, Map.Map n Int)
doRename :: Rename n a -> a
doRename rename = evalState rename (0, Map.empty)
getName :: (Ord n) => n -> Rename n Int
getName thing = do
(i, names) <- get
case names Map.!? thing of
Just name -> pure name
Nothing -> i <$ put (i + 1, Map.insert thing i names)
renameSet :: (Ord v2) => (v1 -> Rename n v2) -> Set.Set v1 -> Rename n (Set.Set v2)
renameSet renameFunc s = Set.fromList <$> (mapM renameFunc $ Set.toList s)
renameMap :: (Ord k2)
=> ((k1, v1) -> Rename n (k2, v2))
-> Map.Map k1 v1
-> Rename n (Map.Map k2 v2)
renameMap f m = Map.fromList <$> (mapM f $ Map.assocs m)
renameKeys :: (Ord k2) => (k1 -> Rename n k2) -> Map.Map k1 v -> Rename n (Map.Map k2 v)
renameKeys f = renameMap (\(k, v) -> (,v) <$> f k)
renameValues :: (Ord k) => (v1 -> Rename n v2) -> Map.Map k v1 -> Rename n (Map.Map k v2)
renameValues f = renameMap (\(k, v) -> (k,) <$> f v)