src/Cryptsy/API/Public/Market.hs

   1 {-# LANGUAGE FlexibleContexts, ViewPatterns #-}
   2 -- |Request for a single market by market id.
   3 module Cryptsy.API.Public.Market
   4         ( module Cryptsy.API.Public.Market
   5         , module Cryptsy.API.Public.Types.Market
   6         , module Cryptsy.API.Public.Types.Monad
   7         )
   8 where
   9
  10 -- text
  11 import Data.Text (Text, unpack)
  12
  13 -- aeson
  14 import Data.Aeson (FromJSON(..), withObject)
  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.Market
  22 import Cryptsy.API.Public.Types.Monad
  23
  24 -- |single market API request
  25 singleMarket :: FromJSON (GMarket p q dt t)
  26              => Text -- ^ marketid
  27              -> PubCryptsy (GMarket p q dt t)
  28 singleMarket (unpack -> reqMarket) = pubCryptsy marketURL $ onMarkets parseSingleMarket
  29  where
  30         marketURL = pubURL $ "singlemarketdata&marketid=" ++ reqMarket
  31         parseSingleMarket = withObject dataStr $ \o ->
  32                 case toList o of
  33                         []       -> fail "No market returned."
  34                         [(_, v)] -> parseJSON v
  35                         _        -> fail "Multiple markets returned."