HIE.Bios

The HIE Bios

Provides an abstraction over the GHC Api to initialise a GHC session and loading modules in a project.

Defines the `hie.yaml` file specification. This is used to explicitly configure how a project should be built by GHC.

Find and load a Cradle

data Cradle a

The environment of a single Cradle. A Cradle is a unit for the respective build-system.

It contains the root directory of the Cradle, the name of the Cradle (for debugging purposes), and knows how to set up a GHC session that is able to compile files that are part of this Cradle.

A Cradle may be a single unit in the "cabal-install" context, or the whole package, comparable to how "stack" works.

Constructors

Cradle

Fields

• cradleRootDir :: FilePath

  The project root directory.

• cradleOptsProg :: CradleAction a

  The action which needs to be executed to get the correct command line arguments.

Instances

Functor Cradle

Defined in HIE.Bios.Types

Methods

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

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

Show a => Show (Cradle a)

Defined in HIE.Bios.Types

Methods

showsPrec :: Int -> Cradle a -> ShowS

show :: Cradle a -> String

showList :: [Cradle a] -> ShowS

data CradleLoadResult r

Result of an attempt to set up a GHC session for a Cradle. This is the go-to error handling mechanism. When possible, this should be preferred over throwing exceptions.

Constructors

CradleSuccess r

The cradle succeeded and returned these options.

CradleFail CradleError

We tried to load the cradle and it failed.

CradleNone

No attempt was made to load the cradle.

Instances

Functor CradleLoadResult

Defined in HIE.Bios.Types

Methods

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

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

Eq r => Eq (CradleLoadResult r)

Defined in HIE.Bios.Types

Methods

(==) :: CradleLoadResult r -> CradleLoadResult r -> Bool

(/=) :: CradleLoadResult r -> CradleLoadResult r -> Bool

Show r => Show (CradleLoadResult r)

Defined in HIE.Bios.Types

Methods

showsPrec :: Int -> CradleLoadResult r -> ShowS

show :: CradleLoadResult r -> String

showList :: [CradleLoadResult r] -> ShowS

data CradleError

Constructors

CradleError

Fields

• cradleErrorDependencies :: [FilePath]

  Dependencies of the cradle that failed to load. Can be watched for changes to attempt a reload of the cradle.

• cradleErrorExitCode :: ExitCode

  ExitCode of the cradle loading mechanism.

• cradleErrorStderr :: [String]

  Standard error output that can be shown to users to explain the loading error.

Instances

Eq CradleError

Defined in HIE.Bios.Types

Methods

(==) :: CradleError -> CradleError -> Bool

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

Show CradleError

Defined in HIE.Bios.Types

Methods

showsPrec :: Int -> CradleError -> ShowS

show :: CradleError -> String

showList :: [CradleError] -> ShowS

Exception CradleError

Defined in HIE.Bios.Types

Methods

toException :: CradleError -> SomeException

fromException :: SomeException -> Maybe CradleError

displayException :: CradleError -> String

findCradle :: FilePath -> IO (Maybe FilePath)

Given root/foo/bar.hs, return root/hie.yaml, or wherever the yaml file was found.

loadCradle :: FilePath -> IO (Cradle Void)

Given root/hie.yaml load the Cradle.

loadImplicitCradle :: Show a => FilePath -> IO (Cradle a)

Given root/foo/bar.hs, load an implicit cradle

defaultCradle :: FilePath -> Cradle a

Default cradle has no special options, not very useful for loading modules.

Compiler Options

data ComponentOptions

Option information for GHC

Constructors

ComponentOptions

Fields

• componentOptions :: [String]

  Command line options.

• componentRoot :: FilePath

  Root directory of the component. All componentOptions are either absolute, or relative to this directory.

• componentDependencies :: [FilePath]

  Dependencies of a cradle that might change the cradle. Contains both files specified in hie.yaml as well as specified by the build-tool if there is any. FilePaths are expected to be relative to the cradleRootDir to which this CradleAction belongs to. Files returned by this action might not actually exist. This is useful, because, sometimes, adding specific files changes the options that a Cradle may return, thus, needs reload as soon as these files are created.

Instances

Eq ComponentOptions

Defined in HIE.Bios.Types

Methods

(==) :: ComponentOptions -> ComponentOptions -> Bool

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

Ord ComponentOptions

Defined in HIE.Bios.Types

Methods

compare :: ComponentOptions -> ComponentOptions -> Ordering

(<) :: ComponentOptions -> ComponentOptions -> Bool

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

(>) :: ComponentOptions -> ComponentOptions -> Bool

(>=) :: ComponentOptions -> ComponentOptions -> Bool

max :: ComponentOptions -> ComponentOptions -> ComponentOptions

min :: ComponentOptions -> ComponentOptions -> ComponentOptions

Show ComponentOptions

Defined in HIE.Bios.Types

Methods

showsPrec :: Int -> ComponentOptions -> ShowS

show :: ComponentOptions -> String

showList :: [ComponentOptions] -> ShowS

getCompilerOptions :: FilePath -> Cradle a -> IO (CradleLoadResult ComponentOptions)

Initialize the DynFlags relating to the compilation of a single file or GHC session according to the provided Cradle.

Initialising a GHC session from a Cradle

initSession :: GhcMonad m => ComponentOptions -> m [Target]

Start a GHC session and set some sensible options for tooling to use. Creates a folder in the cache directory to cache interface files to make reloading faster.

Loading targets into a GHC session

loadFile

Arguments

:: GhcMonad m

=> (FilePath, FilePath)

Target file to load.

-> m (Maybe TypecheckedModule, [TypecheckedModule])

Typechecked module and modules that had to be loaded for the target.

Load a target into the GHC session with the default messager which outputs updates in the same format as normal GHC.

The target is represented as a tuple. The tuple consists of the original filename and another file that contains the actual source code to compile.

If the message should configured, use loadFileWithMessage.

If the loading succeeds, the typechecked module is returned together with all the typechecked modules that had to be loaded in order to typecheck the given target.