Safe Haskell	None

Data.Yaml

Contents

Types
Constructors and accessors
Parsing
Classes
Encoding/decoding
- Better error information
- More control over decoding

Description

Provides a high-level interface for processing YAML files.

This module reuses most of the infrastructure from the aeson package. This means that you can use all of the existing tools for JSON processing for processing YAML files. As a result, much of the documentation below mentions JSON; do not let that confuse you, it's intentional.

For the most part, YAML content translates directly into JSON, and therefore there is very little data loss. If you need to deal with YAML more directly (e.g., directly deal with aliases), you should use the Text.Libyaml module instead.

For documentation on the aeson types, functions, classes, and operators, please see the Data.Aeson module of the aeson package.

Synopsis

Types

data Value

Constructors

Object !Object
Array !Array
String !Text
Number !Number
Bool !Bool
Null

Instances

Eq Value
Show Value
Typeable Value
IsString Value
Hashable Value
NFData Value
ToJSON Value
FromJSON Value

data Parser a

Instances

Monad Parser
Functor Parser
MonadPlus Parser
Applicative Parser
Alternative Parser
Monoid (Parser a)

type Object = HashMap Text Value

type Array = Vector Value

data ParseException

Constructors

NonScalarKey
UnknownAlias
Fields _anchorName :: AnchorName
UnexpectedEvent
Fields _received :: Maybe Event _expected :: Maybe Event
InvalidYaml (Maybe YamlException)
AesonException String
OtherParseException SomeException

Instances

Show ParseException
Typeable ParseException
Exception ParseException

data YamlException

Constructors

YamlException String
YamlParseException	problem, context, index, position line, position column
Fields yamlProblem :: String yamlContext :: String yamlProblemMark :: YamlMark

Instances

Show YamlException
Typeable YamlException
Exception YamlException

data YamlMark

The pointer position

Constructors

YamlMark
Fields yamlIndex :: Int yamlLine :: Int yamlColumn :: Int

Instances

Show YamlMark

Constructors and accessors

object :: [Pair] -> Value

array :: [Value] -> Value

(.=) :: ToJSON a => Text -> a -> Pair

(.:) :: FromJSON a => Object -> Text -> Parser a

(.:?) :: FromJSON a => Object -> Text -> Parser (Maybe a)

(.!=) :: Parser (Maybe a) -> a -> Parser a

Parsing

parseMonad :: Monad m => (a -> Parser b) -> a -> m b

parseEither :: (a -> Parser b) -> a -> Either String b

parseMaybe :: (a -> Parser b) -> a -> Maybe b

Classes

class ToJSON a where

Methods

toJSON :: a -> Value

Instances

ToJSON Bool
ToJSON Char
ToJSON Double
ToJSON Float
ToJSON Int
ToJSON Int8
ToJSON Int16
ToJSON Int32
ToJSON Int64
ToJSON Integer
ToJSON Word
ToJSON Word8
ToJSON Word16
ToJSON Word32
ToJSON Word64
ToJSON ()
ToJSON ByteString
ToJSON ByteString
ToJSON Text
ToJSON Number
ToJSON Text
ToJSON Value
ToJSON DotNetTime
ToJSON ZonedTime
ToJSON IntSet
ToJSON UTCTime
ToJSON [Char]
ToJSON a => ToJSON [a]
ToJSON (Ratio Integer)
ToJSON a => ToJSON (Maybe a)
ToJSON a => ToJSON (First a)
ToJSON a => ToJSON (Last a)
ToJSON a => ToJSON (Dual a)
ToJSON a => ToJSON (HashSet a)
ToJSON a => ToJSON (Vector a)
(Vector Vector a, ToJSON a) => ToJSON (Vector a)
(Storable a, ToJSON a) => ToJSON (Vector a)
(Prim a, ToJSON a) => ToJSON (Vector a)
ToJSON a => ToJSON (IntMap a)
ToJSON a => ToJSON (Set a)
HasResolution a => ToJSON (Fixed a)
(ToJSON a, ToJSON b) => ToJSON (Either a b)
(ToJSON a, ToJSON b) => ToJSON (a, b)
ToJSON v => ToJSON (HashMap String v)
ToJSON v => ToJSON (HashMap ByteString v)
ToJSON v => ToJSON (HashMap ByteString v)
ToJSON v => ToJSON (HashMap Text v)
ToJSON v => ToJSON (HashMap Text v)
ToJSON v => ToJSON (Map String v)
ToJSON v => ToJSON (Map ByteString v)
ToJSON v => ToJSON (Map ByteString v)
ToJSON v => ToJSON (Map Text v)
ToJSON v => ToJSON (Map Text v)
(ToJSON a, ToJSON b, ToJSON c) => ToJSON (a, b, c)
(ToJSON a, ToJSON b, ToJSON c, ToJSON d) => ToJSON (a, b, c, d)

class FromJSON a where

Methods

parseJSON :: Value -> Parser a

Instances

FromJSON Bool
FromJSON Char
FromJSON Double
FromJSON Float
FromJSON Int
FromJSON Int8
FromJSON Int16
FromJSON Int32
FromJSON Int64
FromJSON Integer
FromJSON Word
FromJSON Word8
FromJSON Word16
FromJSON Word32
FromJSON Word64
FromJSON ()
FromJSON ByteString
FromJSON ByteString
FromJSON Text
FromJSON Number
FromJSON Text
FromJSON Value
FromJSON DotNetTime
FromJSON ZonedTime
FromJSON IntSet
FromJSON UTCTime
FromJSON [Char]
FromJSON a => FromJSON [a]
FromJSON (Ratio Integer)
FromJSON a => FromJSON (Maybe a)
FromJSON a => FromJSON (First a)
FromJSON a => FromJSON (Last a)
FromJSON a => FromJSON (Dual a)
(Eq a, Hashable a, FromJSON a) => FromJSON (HashSet a)
FromJSON a => FromJSON (Vector a)
(Vector Vector a, FromJSON a) => FromJSON (Vector a)
(Storable a, FromJSON a) => FromJSON (Vector a)
(Prim a, FromJSON a) => FromJSON (Vector a)
FromJSON a => FromJSON (IntMap a)
(Ord a, FromJSON a) => FromJSON (Set a)
HasResolution a => FromJSON (Fixed a)
(FromJSON a, FromJSON b) => FromJSON (Either a b)
(FromJSON a, FromJSON b) => FromJSON (a, b)
FromJSON v => FromJSON (HashMap String v)
FromJSON v => FromJSON (HashMap ByteString v)
FromJSON v => FromJSON (HashMap ByteString v)
FromJSON v => FromJSON (HashMap Text v)
FromJSON v => FromJSON (HashMap Text v)
FromJSON v => FromJSON (Map String v)
FromJSON v => FromJSON (Map ByteString v)
FromJSON v => FromJSON (Map ByteString v)
FromJSON v => FromJSON (Map Text v)
FromJSON v => FromJSON (Map Text v)
(FromJSON a, FromJSON b, FromJSON c) => FromJSON (a, b, c)
(FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSON (a, b, c, d)

Encoding/decoding

encode :: ToJSON a => a -> ByteString

encodeFile :: ToJSON a => FilePath -> a -> IO ()

decode :: FromJSON a => ByteString -> Maybe a

decodeFile :: FromJSON a => FilePath -> IO (Maybe a)

Better error information

decodeEither :: FromJSON a => ByteString -> Either String a

decodeEither' :: FromJSON a => ByteString -> Either ParseException a

More helpful version of decodeEither which returns the YamlException.

Since 0.8.3

decodeFileEither :: FromJSON a => FilePath -> IO (Either ParseException a)

A version of decodeFile which should not throw runtime exceptions.

Since 0.8.4

More control over decoding

decodeHelper :: FromJSON a => Source Parse Event -> IO (Either ParseException (Either String a))