Exporting data as JSON

A convenient way to store data that may not adhere to a strict schema is through JSON. To accomplish this, we will use a painless JSON library called Yocto. It sacrifices performance for readability and small size.

In this recipe, we will export a list of points as JSON.

Getting ready

Install the Yocto JSON encoder and decoder from cabal using the following command:

$ cabal install yocto

How to do it…

Start by creating a new file, which we call Main.hs and perform the following steps:

1. Import the relevant data structures, as shown in the following code:

   import Text.JSON.Yocto
   import qualified Data.Map as M

2. Define a data structure for 2D points:

   data Point = Point Rational Rational

3. Convert a Point data type into a JSON object, as shown in the following code:

   pointObject (Point x y) = 
     Object $ M.fromList [ ("x", Number x)
                         , ("y", Number y)]

4. Create the points and construct a JSON array out of them:

   main = do
     let points = [ Point...