Jsonifier

Simple DSL for mapping Haskell values into JSON representation and rendering it into ByteString.

ByteString

toByteString :: Json -> ByteString

Render a JSON value into strict bytestring.

toWrite :: Json -> Write

Render a JSON value into Write.

Json

data Json

Specification of how to render a JSON value to ByteString. Sort of a JSON-specialized ByteString builder.

You can construct it from Haskell types using the specialized conversion functions like intNumber, textString or object. After constructing, you can convert to strict ByteString using the toByteString function.

Primitives

null :: Json

JSON Null literal.

bool :: Bool -> Json

JSON Boolean literal.

Numbers

intNumber :: Int -> Json

JSON Number literal from Int.

wordNumber :: Word -> Json

JSON Number literal from Word.

doubleNumber :: Double -> Json

JSON Number literal from Double.

Since JSON doesn't have support for them, non-real values like NaN, Infinity, -Infinity get rendered as 0.

scientificNumber :: Scientific -> Json

JSON Number literal from Scientific.

Strings

textString :: Text -> Json

JSON String literal from Text.

scientificString :: Scientific -> Json

JSON String literal from Scientific.

You may need this when the reader of your JSON cannot handle large number literals.

Composites

array :: Foldable f => f Json -> Json

JSON Array literal from a foldable over element literals.

Don't be afraid to use fmap to map the elements of the input datastructure, it will all be optimized away.

object :: Foldable f => f (Text, Json) -> Json

JSON Object literal from a foldable over pairs of key to value literal.

Don't be afraid to use fmap to map the elements of the input datastructure, it will all be optimized away.

Low-level

writeJson :: Write -> Json

Any JSON literal manually rendered as Write.

This is a low-level function allowing to avoid unnecessary processing in cases where you already have a rendered JSON at hand.

You can think of Write as a specialized version of ByteString builder. You can efficiently convert a ByteString to Write using byteString, making it possible to have parts of the JSON value tree rendered using other libraries. You can as well manually implement encoders for your custom types.

Warning:

It is your responsibility to ensure that the content is correct, otherwise you may produce invalid JSON.