Safe Haskell	Safe-Inferred
Language	Haskell2010

Distribution.Types.CondTree

Synopsis

data CondTree v c a = CondNode {
- condTreeData :: a
- condTreeConstraints :: c
- condTreeComponents :: [CondBranch v c a]
}
data CondBranch v c a = CondBranch {
- condBranchCondition :: Condition v
- condBranchIfTrue :: CondTree v c a
- condBranchIfFalse :: Maybe (CondTree v c a)
}
condIfThen :: Condition v -> CondTree v c a -> CondBranch v c a
condIfThenElse :: Condition v -> CondTree v c a -> CondTree v c a -> CondBranch v c a
foldCondTree :: b -> ((c, a) -> b) -> (b -> b -> b) -> (b -> b -> b) -> CondTree v c a -> b
mapCondTree :: (a -> b) -> (c -> d) -> (Condition v -> Condition w) -> CondTree v c a -> CondTree w d b
mapTreeConstrs :: (c -> d) -> CondTree v c a -> CondTree v d a
mapTreeConds :: (Condition v -> Condition w) -> CondTree v c a -> CondTree w c a
mapTreeData :: (a -> b) -> CondTree v c a -> CondTree v c b
traverseCondTreeV :: forall v c a w f. Applicative f => LensLike f (CondTree v c a) (CondTree w c a) v w
traverseCondBranchV :: forall v c a w f. Applicative f => LensLike f (CondBranch v c a) (CondBranch w c a) v w
traverseCondTreeC :: forall v c a d f. Applicative f => LensLike f (CondTree v c a) (CondTree v d a) c d
traverseCondBranchC :: forall v c a d f. Applicative f => LensLike f (CondBranch v c a) (CondBranch v d a) c d
extractCondition :: Eq v => (a -> Bool) -> CondTree v c a -> Condition v
simplifyCondTree :: (Semigroup a, Semigroup d) => (v -> Either v Bool) -> CondTree v d a -> (d, a)
simplifyCondBranch :: (Semigroup a, Semigroup d) => (v -> Either v Bool) -> CondBranch v d a -> Maybe (d, a)
ignoreConditions :: (Semigroup a, Semigroup c) => CondTree v c a -> (a, c)

Documentation

data CondTree v c a Source #

A CondTree is used to represent the conditional structure of a Cabal file, reflecting a syntax element subject to constraints, and then any number of sub-elements which may be enabled subject to some condition. Both a and c are usually Monoids.

To be more concrete, consider the following fragment of a Cabal file:

build-depends: base >= 4.0
if flag(extra)
    build-depends: base >= 4.2

One way to represent this is to have CondTree ConfVar [Dependency] BuildInfo. Here, condTreeData represents the actual fields which are not behind any conditional, while condTreeComponents recursively records any further fields which are behind a conditional. condTreeConstraints records the constraints (in this case, base >= 4.0) which would be applied if you use this syntax; in general, this is derived off of targetBuildInfo (perhaps a good refactoring would be to convert this into an opaque type, with a smart constructor that pre-computes the dependencies.)

Constructors

CondNode
Fields condTreeData :: a condTreeConstraints :: c condTreeComponents :: [CondBranch v c a]

Instances

Instances details

Functor (CondTree v c) Source #

Instance details

CondBranch
Fields condBranchCondition :: Condition v condBranchIfTrue :: CondTree v c a condBranchIfFalse :: Maybe (CondTree v c a)