Data.Geometry.Geos.Raw.Base

Documentation

data Geos a

Geos is the core context for performing geometric calculations. It handles the foreign function interface as well as error handling. All underlying geos exceptions are represented by a String.

Instances

Monad Geos

Methods

(>>=) :: Geos a -> (a -> Geos b) -> Geos b

(>>) :: Geos a -> Geos b -> Geos b

return :: a -> Geos a

fail :: String -> Geos a

Functor Geos

Methods

fmap :: (a -> b) -> Geos a -> Geos b

(<$) :: a -> Geos b -> Geos a

Applicative Geos

Methods

pure :: a -> Geos a

(<*>) :: Geos (a -> b) -> Geos a -> Geos b

(*>) :: Geos a -> Geos b -> Geos b

(<*) :: Geos a -> Geos b -> Geos a

MonadError String Geos

Methods

throwError :: String -> Geos a

catchError :: Geos a -> (String -> Geos a) -> Geos a

runGeos :: Geos a -> a

Unsafe function for performing a geos calculation. Errors will cause runtime exceptions.

runGeosE :: Geos a -> Either String a

A safe function for performing a geos calculation and returning an Either String a. Exceptions are reprsented as `Left String`

runGeosM :: Geos a -> Maybe a

A safe function for performing a geos calculation and returning a Maybe. Exceptions will be represented as Nothing.

throwIfZero :: (Eq a, Num a, MonadError e m) => (a -> e) -> m a -> m a

throwIfZero' :: (Eq a, Num a, Monad m) => (a -> e) -> m a -> m (Either e a)

throwIfNull :: MonadError String m => String -> m (Ptr a) -> m (Ptr a)

throwIfNull' :: Monad m => String -> m (Ptr a) -> m (Either String (Ptr a))

throwIf :: (Eq a, MonadError e m) => (a -> Bool) -> (a -> e) -> m a -> m a

throwIf' :: (Eq a, Monad m, MonadError e me) => (a -> Bool) -> (a -> e) -> m a -> m (me a)

withGeos :: (GEOSContextHandle_t -> IO a) -> Geos a

withGeos' :: (GEOSContextHandle_t -> IO (Either String a)) -> Geos a

mkErrorMessage :: Show a => String -> a -> String

marshallInt :: (Integral i, Storable i) => Ptr i -> IO Int

marshallDouble :: (Real r, Storable r) => Ptr r -> IO Double

geosUnit :: Geos ()