Data.Bson

A BSON document is a JSON-like object with a standard binary encoding defined at bsonspec.org. This implements version 1.0 of that spec.

Use the GHC language extension OverloadedStrings to automatically convert String literals to Text

Document

type Document = [Field]

A BSON document is a list of Fields

(!?) :: Val a => Document -> Label -> Maybe a

Recursively lookup a nested field in a Document.

look :: Monad m => Label -> Document -> m Value

Value of field in document, or fail (Nothing) if field not found

lookup :: (Val v, Monad m) => Label -> Document -> m v

Lookup value of field in document and cast to expected type. Fail (Nothing) if field not found or value not of expected type.

valueAt :: Label -> Document -> Value

Value of field in document. Error if missing.

at :: forall v. Val v => Label -> Document -> v

Typed value of field in document. Error if missing or wrong type.

include :: [Label] -> Document -> Document

Only include fields of document in label list

exclude :: [Label] -> Document -> Document

Exclude fields from document in label list

merge :: Document -> Document -> Document

Merge documents with preference given to first one when both have the same label. I.e. for every (k := v) in first argument, if k exists in second argument then replace its value with v, otherwise add (k := v) to second argument.

Field

data Field

A BSON field is a named value, where the name (label) is a string and the value is a BSON Value

Constructors

:=

Fields

label :: !Label

value :: Value

Instances

Eq Field

Ord Field

Show Field

Typeable Field

Val Document

(=:) :: Val v => Label -> v -> Field

Field with given label and typed value

(=?) :: Val a => Label -> Maybe a -> Document

If Just value then return one field document, otherwise return empty document

type Label = Text

The name of a BSON field

Value

data Value

A BSON value is one of the following types of values

Constructors

Float Double

String Text

Doc Document

Array [Value]

Bin Binary

Fun Function

Uuid UUID

Md5 MD5

UserDef UserDefined

ObjId ObjectId

Bool Bool

UTC UTCTime

Null

RegEx Regex

JavaScr Javascript

Sym Symbol

Int32 Int32

Int64 Int64

Stamp MongoStamp

MinMax MinMaxKey

Instances

Eq Value

Ord Value

Show Value

Typeable Value

Val [Value]

Val (Maybe Value)

class (Typeable a, Show a, Eq a) => Val a where

Haskell types of this class correspond to BSON value types

Methods

val :: a -> Value

cast' :: Value -> Maybe a

Instances

Val Bool

Val Double

Val Float

Val Int

Val Int32

Val Int64

Val Integer

Val String

Val Text

Val POSIXTime

Val UTCTime

Val ObjectId

Val MinMaxKey

Val MongoStamp

Val Symbol

Val Javascript

Val Regex

Val UserDefined

Val MD5

Val UUID

Val Function

Val Binary

Val Document

Val a => Val [a]

Val [Value]

Val a => Val (Maybe a)

Val (Maybe Value)

fval :: (forall a. Val a => a -> b) -> Value -> b

Apply generic function to typed value

cast :: forall m a. (Val a, Monad m) => Value -> m a

Convert Value to expected type, or fail (Nothing) if not of that type

typed :: Val a => Value -> a

Convert Value to expected type. Error if not that type.

typeOfVal :: Value -> TypeRep

Type of typed value

Special Bson value types

newtype Binary

Constructors

Binary ByteString

Instances

Eq Binary

Ord Binary

Read Binary

Show Binary

Typeable Binary

Val Binary

newtype Function

Constructors

Function ByteString

Instances

Eq Function

Ord Function

Read Function

Show Function

Typeable Function

Val Function

newtype UUID

Constructors

UUID ByteString

Instances

Eq UUID

Ord UUID

Read UUID

Show UUID

Typeable UUID

Val UUID

newtype MD5

Constructors

MD5 ByteString

Instances

Eq MD5

Ord MD5

Read MD5

Show MD5

Typeable MD5

Val MD5

newtype UserDefined

Constructors

UserDefined ByteString

Instances

Eq UserDefined

Ord UserDefined

Read UserDefined

Show UserDefined

Typeable UserDefined

Val UserDefined

data Regex

The first string is the regex pattern, the second is the regex options string. Options are identified by characters, which must be listed in alphabetical order. Valid options are *i* for case insensitive matching, *m* for multiline matching, *x* for verbose mode, *l* to make \w, \W, etc. locale dependent, *s* for dotall mode ("." matches everything), and *u* to make \w, \W, etc. match unicode.

Constructors

Regex Text Text

Instances

Eq Regex

Ord Regex

Read Regex

Show Regex

Typeable Regex

Val Regex

data Javascript

Javascript code with possibly empty environment mapping variables to values that the code may reference

Constructors

Javascript Document Text

Instances

Eq Javascript

Ord Javascript

Show Javascript

Typeable Javascript

Val Javascript

newtype Symbol

Constructors

Symbol Text

Instances

Eq Symbol

Ord Symbol

Read Symbol

Show Symbol

Typeable Symbol

Val Symbol

newtype MongoStamp

Constructors

MongoStamp Int64

Instances

Eq MongoStamp

Ord MongoStamp

Read MongoStamp

Show MongoStamp

Typeable MongoStamp

Val MongoStamp

data MinMaxKey

Constructors

MinKey

MaxKey

Instances

Eq MinMaxKey

Ord MinMaxKey

Read MinMaxKey

Show MinMaxKey

Typeable MinMaxKey

Val MinMaxKey

ObjectId

data ObjectId

A BSON ObjectID is a 12-byte value consisting of a 4-byte timestamp (seconds since epoch), a 3-byte machine id, a 2-byte process id, and a 3-byte counter. Note that the timestamp and counter fields must be stored big endian unlike the rest of BSON. This is because they are compared byte-by-byte and we want to ensure a mostly increasing order.

Constructors

Oid Word32 Word64

Instances

Eq ObjectId

Ord ObjectId

Read ObjectId

Show ObjectId

Typeable ObjectId

Val ObjectId

timestamp :: ObjectId -> UTCTime

Time when objectId was created

genObjectId :: IO ObjectId

Create a fresh ObjectId