Dep.Loader

Define resource Loaders and wire them into Values.

Typically, this module only needs to be imported when creating the global application environment.

Resource loader.

newtype Loader v m

Constructors

Loader

Fields

• loadMaybe :: ResourceKey -> m (Maybe v)

Instances

Generic (Loader v m)

Defined in Dep.Loader

Associated Types

type Rep (Loader v m) :: Type -> Type

Methods

from :: Loader v m -> Rep (Loader v m) x

to :: Rep (Loader v m) x -> Loader v m

Monad m => Semigroup (Loader v m)

The left Loader is consulted first.

Defined in Dep.Loader

Methods

(<>) :: Loader v m -> Loader v m -> Loader v m

sconcat :: NonEmpty (Loader v m) -> Loader v m

stimes :: Integral b => b -> Loader v m -> Loader v m

Monad m => Monoid (Loader v m)

Defined in Dep.Loader

Methods

mempty :: Loader v m

mappend :: Loader v m -> Loader v m -> Loader v m

mconcat :: [Loader v m] -> Loader v m

type Rep (Loader v m)

Defined in Dep.Loader

type Rep (Loader v m) = D1 ('MetaData "Loader" "Dep.Loader" "dep-t-value-0.1.0.0-9HathWkr8833kq2ESFmsQK" 'True) (C1 ('MetaCons "Loader" 'PrefixI 'True) (S1 ('MetaSel ('Just "loadMaybe") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (ResourceKey -> m (Maybe v)))))

data ResourceKey

Constructors

ResourceKey

Fields

• modulePath :: [ModuleName]
• datatypeName :: DatatypeName

Instances

Eq ResourceKey

Defined in Dep.Loader

Methods

(==) :: ResourceKey -> ResourceKey -> Bool

(/=) :: ResourceKey -> ResourceKey -> Bool

Ord ResourceKey

Defined in Dep.Loader

Methods

compare :: ResourceKey -> ResourceKey -> Ordering

(<) :: ResourceKey -> ResourceKey -> Bool

(<=) :: ResourceKey -> ResourceKey -> Bool

(>) :: ResourceKey -> ResourceKey -> Bool

(>=) :: ResourceKey -> ResourceKey -> Bool

max :: ResourceKey -> ResourceKey -> ResourceKey

min :: ResourceKey -> ResourceKey -> ResourceKey

Show ResourceKey

Defined in Dep.Loader

Methods

showsPrec :: Int -> ResourceKey -> ShowS

show :: ResourceKey -> String

showList :: [ResourceKey] -> ShowS

type DatatypeName = String

type ModuleName = String

load :: forall r v m. (FromResource r, Typeable r, Typeable v, Monad m) => Loader v m -> m v

Throws ResourceNotFound.

data ResourceNotFound

Constructors

ResourceNotFound TypeRep ResourceKey TypeRep

Instances

Show ResourceNotFound

Defined in Dep.Loader

Methods

showsPrec :: Int -> ResourceNotFound -> ShowS

show :: ResourceNotFound -> String

showList :: [ResourceNotFound] -> ShowS

Exception ResourceNotFound

Defined in Dep.Loader

Methods

toException :: ResourceNotFound -> SomeException

fromException :: SomeException -> Maybe ResourceNotFound

displayException :: ResourceNotFound -> String

Datatypes tied to resources.

class FromResource a where

Class for datatypes tied to resources.

Derive it with DeriveAnyClass. The datatype must have a GHC.Generics.Generic instance.

Minimal complete definition

Nothing

Methods

resourceKey :: ResourceKey

default resourceKey :: forall name mod p n nt x. (Generic a, Rep a ~ D1 ('MetaData name mod p nt) x, KnownSymbol name, KnownSymbol mod) => ResourceKey

Loaders for resources in a directory.

dataDirLoader :: MonadIO m => [FileExtension] -> DataDir -> Loader ByteString m

A dataDirLoader ["js", "json"] (dataDir "conf") Loader will, for a datatype Baz defined in module Foo.Bar, look for the files conf/Foo/Bar/Baz.js and conf/Foo/Bar/Baz.json, in that order.

type FileExtension = String

type DataDir = FilePath -> IO FilePath

Function that completes a relative FilePath pointing to a data file, and returns its absolute path.

The getDataFileName function from Paths_pkgname is a valid DataDir. You can also create a DataDir by using dataDir.

dataDir :: FilePath -> DataDir

Build a DataDir out of a base directory path.

extendDataDir :: DataDir -> FilePath -> DataDir

Given a relative path to a subdirectory of a DataDir, return a DataDir that completes paths within that subdirectory.