Hello, I have this JSON string that I have put in a text file, test.json: {"coordinates": [0.0, 1.0]} using GHCi, I can read it like this:
s <- readFile "test.json" let r = decode s :: Result JSValue r Ok (JSObject (JSONObject {fromJSObject = [("coordinates",JSArray [JSRational False (0 % 1),JSRational False (1 % 1)])]}))
I want to affect this array of two Double to the type Coordinates being defined like this: type Coordinates = (Double, Double) Using this type I can create a Node: data Node = Node Coordinates Number deriving (Eq, Ord, Show) The problem is that I have no idea what to do with decoded JSValue. It seems I have to define an instance of JSON to read it. Does this mean using pattern matching to extract the values ? What do I do with the Result type ? Should I get rid of it like this: fromResult :: Result JSValue -> JSValue fromResult (Ok js) = js fromResult _ = JSNull and work with the raw JValue ? These questions might be trivial, but I know only imperative languages, which is why I like so much to learn Haskell and functional programming, lots to learn and discover :) Many thanks in advance, Adrien