module Distribution.Solver.Modular.Index
( Index
, PInfo(..)
, defaultQualifyOptions
, mkIndex
) where
import Data.List as L
import Data.Map as M
import Prelude hiding (pi)
import Distribution.Solver.Modular.Dependency
import Distribution.Solver.Modular.Flag
import Distribution.Solver.Modular.Package
import Distribution.Solver.Modular.Tree
import Distribution.Types.UnqualComponentName
-- | An index contains information about package instances. This is a nested
-- dictionary. Package names are mapped to instances, which in turn is mapped
-- to info.
type Index = Map PN (Map I PInfo)
-- | Info associated with a package instance.
-- Currently, dependencies, executable names, flags and failure reasons.
-- Packages that have a failure reason recorded for them are disabled
-- globally, for reasons external to the solver. We currently use this
-- for shadowing which essentially is a GHC limitation, and for
-- installed packages that are broken.
data PInfo = PInfo (FlaggedDeps PN) [UnqualComponentName] FlagInfo (Maybe FailReason)
mkIndex :: [(PN, I, PInfo)] -> Index
mkIndex xs = M.map M.fromList (groupMap (L.map (\ (pn, i, pi) -> (pn, (i, pi))) xs))
groupMap :: Ord a => [(a, b)] -> Map a [b]
groupMap xs = M.fromListWith (flip (++)) (L.map (\ (x, y) -> (x, [y])) xs)
defaultQualifyOptions :: Index -> QualifyOptions
defaultQualifyOptions idx = QO {
qoBaseShim = or [ dep == base
| -- Find all versions of base ..
Just is <- [M.lookup base idx]
-- .. which are installed ..
, (I _ver (Inst _), PInfo deps _exes _flagNfo _fr) <- M.toList is
-- .. and flatten all their dependencies ..
, (LDep _ (Dep _is_exe dep _ci), _comp) <- flattenFlaggedDeps deps
]
, qoSetupIndependent = True
}
where
base = mkPackageName "base"