Ormolu

A formatter for Haskell source code.

Documentation

ormolu

Arguments

:: MonadIO m

=> Config

Ormolu configuration

-> FilePath

Location of source file

-> String

Input to format

-> m Text

Format a String, return formatted version as Text.

The function

• Takes String because that's what GHC parser accepts.
• Needs IO because some functions from GHC that are necessary to setup parsing context require IO. There should be no visible side-effects though.
• Takes file name just to use it in parse error messages.
• Throws OrmoluException.

ormoluFile

Arguments

:: MonadIO m

=> Config

Ormolu configuration

-> FilePath

Location of source file

-> m Text

Resulting rendition

Load a file and format it. The file stays intact and the rendered version is returned as Text.

ormoluFile cfg path =
  liftIO (readFile path) >>= ormolu cfg path

ormoluStdin

Arguments

:: MonadIO m

=> Config

Ormolu configuration

-> m Text

Resulting rendition

Read input from stdin and format it.

ormoluStdin cfg =
  liftIO (hGetContents stdin) >>= ormolu cfg "<stdin>"

data Config

Ormolu configuration.

Constructors

Config

Fields

• cfgDynOptions :: ![DynOption]

  Dynamic options to pass to GHC parser

• cfgUnsafe :: !Bool

  Do formatting faster but without automatic detection of defects

• cfgDebug :: !Bool

  Output information useful for debugging

• cfgTolerateCpp :: !Bool

  Do not fail if CPP pragma is present (still doesn't handle CPP but useful for formatting of files that enable the extension without actually containing CPP macros)

• cfgCheckIdempotency :: !Bool

  Checks if re-formatting the result is idempotent.

Instances

Eq Config

Defined in Ormolu.Config

Methods

(==) :: Config -> Config -> Bool

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

Show Config

Defined in Ormolu.Config

Methods

showsPrec :: Int -> Config -> ShowS

show :: Config -> String

showList :: [Config] -> ShowS

defaultConfig :: Config

Default Config.

newtype DynOption

A wrapper for dynamic options.

Constructors

DynOption

Fields

• unDynOption :: String

Instances

Eq DynOption

Defined in Ormolu.Config

Methods

(==) :: DynOption -> DynOption -> Bool

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

Ord DynOption

Defined in Ormolu.Config

Methods

compare :: DynOption -> DynOption -> Ordering

(<) :: DynOption -> DynOption -> Bool

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

(>) :: DynOption -> DynOption -> Bool

(>=) :: DynOption -> DynOption -> Bool

max :: DynOption -> DynOption -> DynOption

min :: DynOption -> DynOption -> DynOption

Show DynOption

Defined in Ormolu.Config

Methods

showsPrec :: Int -> DynOption -> ShowS

show :: DynOption -> String

showList :: [DynOption] -> ShowS

data OrmoluException

Ormolu exception representing all cases when Ormolu can fail.

Constructors

OrmoluCppEnabled FilePath

Ormolu does not work with source files that use CPP

OrmoluParsingFailed SrcSpan String

Parsing of original source code failed

OrmoluOutputParsingFailed SrcSpan String

Parsing of formatted source code failed

OrmoluASTDiffers FilePath [SrcSpan]

Original and resulting ASTs differ

OrmoluNonIdempotentOutput RealSrcLoc Text Text

Formatted source code is not idempotent

Instances

Eq OrmoluException

Defined in Ormolu.Exception

Methods

(==) :: OrmoluException -> OrmoluException -> Bool

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

Show OrmoluException

Defined in Ormolu.Exception

Methods

showsPrec :: Int -> OrmoluException -> ShowS

show :: OrmoluException -> String

showList :: [OrmoluException] -> ShowS

Exception OrmoluException

Defined in Ormolu.Exception

Methods

toException :: OrmoluException -> SomeException

fromException :: SomeException -> Maybe OrmoluException

displayException :: OrmoluException -> String

withPrettyOrmoluExceptions

Arguments

:: IO a

Action that may throw the exception

-> IO a

Inside this wrapper OrmoluException will be caught and displayed nicely using displayException.