module Tables2(DTable(..), dtable0, lookupDe, listDe, subDes, updateDe) where
import Data.List(partition)
import Utils(pair)
--import Direction() -- instances, for hbc
import Path(Path,subPath)
import Sockets(Descriptor)
import Table

type DTable = Table Descriptor Path

updateDe :: Path -> [Descriptor] -> DTable -> DTable
updateDe path' ds dtable =
    table (map (`pair` path') ds ++
           filter ((/= path') . snd) (listTable dtable))

listDe :: DTable -> [Descriptor]
listDe dtable = map fst (listTable dtable)

--findDe :: DTable -> Path -> [Descriptor]
--findDe dtable path = [de | (de,path') <- listTable dtable, path'==path]

subDes :: DTable -> Path -> ([Descriptor],DTable)
subDes dtable path = (map fst children,table other)
  where (children,other) = partition (subPath path.snd) (listTable dtable)

lookupDe :: DTable -> Descriptor -> Path
lookupDe dtable de =
    tableLookup (error ("Descriptor without path: "++show de)) snd de dtable

dtable0 :: DTable
dtable0 = table []