src/Cryptsy/API/Public/OrderBook.hs

   1 {-# LANGUAGE FlexibleContexts, ViewPatterns #-}
   2 -- |Request for a single order book by market id.
   3 module Cryptsy.API.Public.OrderBook
   4         ( module Cryptsy.API.Public.OrderBook
   5         , module Cryptsy.API.Public.Types.Monad
   6         , module Cryptsy.API.Public.Types.OrderBook
   7         )
   8 where
   9
  10 -- aeson
  11 import Data.Aeson (FromJSON(..), withObject)
  12
  13 -- text
  14 import Data.Text (Text, unpack)
  15
  16 -- unordered-containers
  17 import Data.HashMap.Strict (toList)
  18
  19 -- this package
  20 import Cryptsy.API.Public.Internal
  21 import Cryptsy.API.Public.Types.Monad
  22 import Cryptsy.API.Public.Types.OrderBook
  23
  24 -- |single orderbook API request
  25 singleOrderBook :: FromJSON (GOrderBook p q t)
  26                 => Text -- ^ marketid
  27                 -> PubCryptsy (GOrderBook p q t)
  28 singleOrderBook (unpack -> reqMarket) =
  29         pubCryptsy orderBookURL parseSingleOrderBook
  30  where
  31         orderBookURL = pubURL $ "singleorderdata&marketid=" ++ reqMarket
  32         parseSingleOrderBook = withObject dataStr $ \o ->
  33                 case toList o of
  34                         []       -> fail "No order book returned."
  35                         [(_, v)] -> parseJSON v
  36                         _        -> fail "Multiple order books returned."
  37 {-# INLINABLE singleOrderBook #-}