TOML.Decode

Decoding functions

decode :: DecodeTOML a => Text -> Either TOMLError a

Decode the given TOML input.

decodeWith :: Decoder a -> Text -> Either TOMLError a

Decode the given TOML input using the given Decoder.

decodeWithOpts :: Decoder a -> String -> Text -> Either TOMLError a

decodeFile :: DecodeTOML a => FilePath -> IO (Either TOMLError a)

Decode a TOML file at the given file path.

Decoder interface

class DecodeTOML a where

A type class containing the default Decoder for the given type.

See the docs for Decoder for examples.

Methods

tomlDecoder :: Decoder a

Instances

DecodeTOML Version

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Version

DecodeTOML Void

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Void

DecodeTOML Int16

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Int16

DecodeTOML Int32

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Int32

DecodeTOML Int64

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Int64

DecodeTOML Int8

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Int8

DecodeTOML Word16

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Word16

DecodeTOML Word32

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Word32

DecodeTOML Word64

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Word64

DecodeTOML Word8

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Word8

DecodeTOML IntSet

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder IntSet

DecodeTOML Ordering

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Ordering

DecodeTOML Text

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Text

DecodeTOML Text

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Text

DecodeTOML CalendarDiffDays

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder CalendarDiffDays

DecodeTOML Day

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Day

DecodeTOML DayOfWeek

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder DayOfWeek

DecodeTOML DiffTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder DiffTime

DecodeTOML NominalDiffTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder NominalDiffTime

DecodeTOML SystemTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder SystemTime

DecodeTOML UTCTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder UTCTime

DecodeTOML CalendarDiffTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder CalendarDiffTime

DecodeTOML LocalTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder LocalTime

DecodeTOML TimeOfDay

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder TimeOfDay

DecodeTOML ZonedTime

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder ZonedTime

DecodeTOML Value

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Value

DecodeTOML String

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder String

DecodeTOML Integer

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Integer

DecodeTOML Natural

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Natural

DecodeTOML ()

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder ()

DecodeTOML Bool

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Bool

DecodeTOML Char

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Char

DecodeTOML Double

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Double

DecodeTOML Float

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Float

DecodeTOML Int

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Int

DecodeTOML Word

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder Word

DecodeTOML a => DecodeTOML (Identity a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Identity a)

DecodeTOML a => DecodeTOML (First a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (First a)

DecodeTOML a => DecodeTOML (Last a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Last a)

DecodeTOML a => DecodeTOML (First a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (First a)

DecodeTOML a => DecodeTOML (Last a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Last a)

DecodeTOML a => DecodeTOML (Max a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Max a)

DecodeTOML a => DecodeTOML (Min a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Min a)

DecodeTOML a => DecodeTOML (Dual a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Dual a)

Integral a => DecodeTOML (Ratio a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Ratio a)

DecodeTOML a => DecodeTOML (IntMap a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (IntMap a)

DecodeTOML a => DecodeTOML (Seq a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Seq a)

(DecodeTOML a, Ord a) => DecodeTOML (Set a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Set a)

DecodeTOML a => DecodeTOML (NonEmpty a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (NonEmpty a)

DecodeTOML a => DecodeTOML (Maybe a)

Since TOML doesn't support literal NULLs, this will only ever return Just. To get the absence of a field, use getFieldOpt or one of its variants.

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Maybe a)

DecodeTOML a => DecodeTOML [a]

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder [a]

(DecodeTOML a, DecodeTOML b) => DecodeTOML (Either a b)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Either a b)

HasResolution a => DecodeTOML (Fixed a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Fixed a)

DecodeTOML (Proxy a)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Proxy a)

(IsString k, Ord k, DecodeTOML v) => DecodeTOML (Map k v)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Map k v)

(DecodeTOML a, DecodeTOML b) => DecodeTOML (a, b)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (a, b)

DecodeTOML a => DecodeTOML (Const a b)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (Const a b)

(DecodeTOML a, DecodeTOML b, DecodeTOML c) => DecodeTOML (a, b, c)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (a, b, c)

(DecodeTOML a, DecodeTOML b, DecodeTOML c, DecodeTOML d) => DecodeTOML (a, b, c, d)

Defined in TOML.Decode

Methods

tomlDecoder :: Decoder (a, b, c, d)

newtype Decoder a

A Decoder a represents a function for decoding a TOML value to a value of type a.

Generally, you'd only need to chain the getField* functions together, like

decoder =
  MyConfig
    <$> getField "a"
    <*> getField "b"
    <*> getField "c"

or use interfaces like Monad and Alternative:

decoder = do
  cfgType <- getField "type"
  case cfgType of
    "int" -> MyIntValue <$> (getField "int" <|> getField "integer")
    "bool" -> MyBoolValue <$> getField "bool"
    _ -> fail $ "Invalid type: " <> cfgType

but you can also manually implement a Decoder with makeDecoder.

Constructors

Decoder

Fields

• unDecoder :: Value -> DecodeM a

Instances

MonadFail Decoder

Defined in TOML.Decode

Methods

fail :: String -> Decoder a

Alternative Decoder

Defined in TOML.Decode

Methods

empty :: Decoder a

(<|>) :: Decoder a -> Decoder a -> Decoder a

some :: Decoder a -> Decoder [a]

many :: Decoder a -> Decoder [a]

Applicative Decoder

Defined in TOML.Decode

Methods

pure :: a -> Decoder a

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

liftA2 :: (a -> b -> c) -> Decoder a -> Decoder b -> Decoder c

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

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

Functor Decoder

Defined in TOML.Decode

Methods

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

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

Monad Decoder

Defined in TOML.Decode

Methods

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

(>>) :: Decoder a -> Decoder b -> Decoder b

return :: a -> Decoder a

Decoder getters

getField :: DecodeTOML a => Text -> Decoder a

Decode a field in a TOML Value. Equivalent to getFields with a single-element list.

a = 1
b = asdf

-- MyConfig 1 "asdf"
MyConfig <$> getField "a" <*> getField "b"

getFieldOr :: DecodeTOML a => a -> Text -> Decoder a

Decode a field in a TOML Value or succeed with a default value when the field is missing.

a = 1
# b is missing

-- MyConfig 1 "asdf"
MyConfig <$> getFieldOr 42 "a" <*> getFieldOr "asdf" "b"

getFields :: DecodeTOML a => [Text] -> Decoder a

Decode a nested field in a TOML Value.

a.b = 1

-- MyConfig 1
MyConfig <$> getFields ["a", "b"]

getFieldOpt :: DecodeTOML a => Text -> Decoder (Maybe a)

Decode a field in a TOML Value, or Nothing if the field doesn't exist. Equivalent to getFieldsOpt with a single-element list.

a = 1

-- MyConfig (Just 1) Nothing
MyConfig <$> getFieldOpt "a" <*> getFieldOpt "b"

getFieldsOpt :: DecodeTOML a => [Text] -> Decoder (Maybe a)

Decode a nested field in a TOML Value, or Nothing if any of the fields don't exist.

a.b = 1

-- MyConfig (Just 1) Nothing Nothing
MyConfig
  <$> getFieldsOpt ["a", "b"]
  <*> getFieldsOpt ["a", "c"]
  <*> getFieldsOpt ["b", "c"]

getFieldWith :: Decoder a -> Text -> Decoder a

Same as getField, except with the given Decoder.

getFieldsWith :: Decoder a -> [Text] -> Decoder a

Same as getFields, except with the given Decoder.

getFieldOptWith :: Decoder a -> Text -> Decoder (Maybe a)

Same as getFieldOpt, except with the given Decoder.

getFieldsOptWith :: Decoder a -> [Text] -> Decoder (Maybe a)

Same as getFieldsOpt, except with the given Decoder.

getArrayOf :: Decoder a -> Decoder [a]

Decode a list of values using the given Decoder.

[[a]]
b = 1

[[a]]
b = 2

-- MyConfig [1, 2]
MyConfig
  <$> getFieldWith (getArrayOf (getField "b")) "a"

Build custom Decoder

newtype DecodeM a

The underlying decoding monad that either returns a value of type a or returns an error.

Constructors

DecodeM

Fields

• unDecodeM :: DecodeContext -> Either (DecodeContext, DecodeError) a

Instances

MonadFail DecodeM

Defined in TOML.Decode

Methods

fail :: String -> DecodeM a

Alternative DecodeM

Defined in TOML.Decode

Methods

empty :: DecodeM a

(<|>) :: DecodeM a -> DecodeM a -> DecodeM a

some :: DecodeM a -> DecodeM [a]

many :: DecodeM a -> DecodeM [a]

Applicative DecodeM

Defined in TOML.Decode

Methods

pure :: a -> DecodeM a

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

liftA2 :: (a -> b -> c) -> DecodeM a -> DecodeM b -> DecodeM c

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

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

Functor DecodeM

Defined in TOML.Decode

Methods

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

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

Monad DecodeM

Defined in TOML.Decode

Methods

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

(>>) :: DecodeM a -> DecodeM b -> DecodeM b

return :: a -> DecodeM a

makeDecoder :: (Value -> DecodeM a) -> Decoder a

Manually implement a Decoder with the given function.

runDecoder :: Decoder a -> Value -> DecodeM a

Run a Decoder with the given Value.

makeDecoder $ \v -> do
  a <- runDecoder decoder1 v
  b <- runDecoder decoder2 v
  return (a, b)

Satisfies

makeDecoder . runDecoder === id
runDecoder . makeDecoder === id

addContextItem :: ContextItem -> DecodeM a -> DecodeM a

invalidValue :: Text -> Value -> DecodeM a

Throw an error indicating that the given Value is invalid.

makeDecoder $ \v ->
  case v of
    Integer 42 -> invalidValue "We don't like this number" v
    _ -> runDecoder tomlDecoder v

-- or alternatively,
tomlDecoder >>= case
  42 -> makeDecoder $ invalidValue "We don't like this number"
  v -> pure v

typeMismatch :: Value -> DecodeM a

Throw an error indicating that the given Value isn't the correct type of value.

makeDecoder $ \v ->
  case v of
    String s -> ...
    _ -> typeMismatch v

decodeFail :: Text -> DecodeM a

Throw a generic failure message.

decodeError :: DecodeError -> DecodeM a

Throw the given TOMLError.