Decoding.hs

-- | Decoding functions for JSON data

module Hydra.Langs.Json.Decoding where

import qualified Hydra.Compute as Compute
import qualified Hydra.Json as Json
import qualified Hydra.Lib.Flows as Flows
import qualified Hydra.Lib.Maps as Maps
import qualified Hydra.Lib.Strings as Strings
import Data.Int
import Data.List as L
import Data.Map as M
import Data.Set as S

decodeString :: (Json.Value -> Compute.Flow s String)
decodeString x = case x of
  Json.ValueString v277 -> (Flows.pure v277)
  _ -> (Flows.fail "expected a string")

decodeNumber :: (Json.Value -> Compute.Flow s Double)
decodeNumber x = case x of
  Json.ValueNumber v278 -> (Flows.pure v278)
  _ -> (Flows.fail "expected a number")

decodeBoolean :: (Json.Value -> Compute.Flow s Bool)
decodeBoolean x = case x of
  Json.ValueBoolean v279 -> (Flows.pure v279)
  _ -> (Flows.fail "expected a boolean")

decodeArray :: ((Json.Value -> Compute.Flow s a) -> Json.Value -> Compute.Flow s [a])
decodeArray decodeElem x = case x of
  Json.ValueArray v280 -> (Flows.mapList decodeElem v280)
  _ -> (Flows.fail "expected an array")

decodeObject :: (Json.Value -> Compute.Flow s (Map String Json.Value))
decodeObject x = case x of
  Json.ValueObject v281 -> (Flows.pure v281)
  _ -> (Flows.fail "expected an object")

decodeField :: ((Json.Value -> Compute.Flow s a) -> String -> Map String Json.Value -> Compute.Flow s a)
decodeField decodeValue name m = (Flows.bind (decodeOptionalField decodeValue name m) (\x -> case x of
  Nothing -> (Flows.fail (Strings.cat [
    "missing field: ",
    name]))
  Just v282 -> (Flows.pure v282)))

decodeOptionalField :: ((Json.Value -> Compute.Flow s a) -> String -> Map String Json.Value -> Compute.Flow s (Maybe a))
decodeOptionalField decodeValue name m = ((\x -> case x of
  Nothing -> (Flows.pure Nothing)
  Just v283 -> (Flows.map (\x -> Just x) (decodeValue v283))) (Maps.lookup name m))