blob: 61bebfdc7eeb9936c8d9300951a14befc6a52b45 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
|
{-# LANGUAGE DeriveGeneric #-}
module Model.Types
( ItemDate(..)
, isNever, isUnknown, isKnown
) where
import ClassyPrelude.Yesod
data ItemDate = DateUnknown | DateKnown Day | DateNever
deriving (Eq, Ord, Show, Read, Generic)
isNever, isUnknown, isKnown :: ItemDate -> Bool
isNever DateNever = True
isNever _ = False
isUnknown DateUnknown = True
isUnknown _ = False
isKnown (DateKnown _) = True
isKnown _ = False
unknownVerb :: IsString a => a
unknownVerb = "unknown"
instance ToJSON ItemDate where
toJSON DateNever = Null
toJSON DateUnknown = String unknownVerb
toJSON (DateKnown d) = toJSON d
instance FromJSON ItemDate where
parseJSON Null = pure DateNever
parseJSON v@(String inp)
| unknownVerb == inp = pure DateUnknown
| otherwise = DateKnown <$> parseJSON v
parseJSON v = DateKnown <$> parseJSON v
derivePersistFieldJSON "ItemDate"
|
