Convert bitcoin value based on exchange rate from JSON API

Question

I’m learning F# and trying to find a more ‘functional’ way to code a simple program that retrieves the price of BTC and calculates the EUR value of an amount of Bitcoin.

open System
open System.Net
open Newtonsoft.Json.Linq
let myBTC = 0.1234567
let client = new WebClient()
client.UseDefaultCredentials = true
let priceInfo = client.DownloadString("https://blockchain.info/ticker")
let jPrice = JObject.Parse priceInfo
let eurPrice = float (jPrice.["EUR"].["buy"] :?> JValue)
let calcWorth = myBTC * eurPrice
printfn "%s" calcWorth.ToString("N")

Answer 1

My take is that there is no harm in adding a few named functions. Also it is probably better to ignore the result of setting a standard .net property.

open System
open System.Net
open Newtonsoft.Json.Linq
let downloadPriceInfo () =
 let client = new WebClient()
 client.DownloadString("https://blockchain.info/ticker")
let getPriceOfEuro (price: JObject) = float (price.["EUR"].["buy"] :?> JValue)
let euroToBtc euro = 0.1234567 * euro
let btcOfEuro = 
 downloadPriceInfo () 
 |> JObject.Parse
 |> getPriceOfEuro 
 |> euroToBtc
printfn "%s" (btcOfEuro.ToString("N"))

• VoronoiPotato: Some suggestions, which may or may not be useful... |> parseJObject is equivalent to |> JObject.Parse. jPrice might better be named price since the type definition is fully specified here. euroPrice might be better named euro since the function is EuroToBtc. I'm pretty sure client.UseDefaultCredentials = true doesn't actually do anything.
• ChaosPandion: @VoronoiPotato - You make some good points.
• VoronoiPotato: always happy to help :)