Data X = X { a :: Int <?> "b"

Question

Data X = X { a :: Int <?> "b"

, c :: Int <?> "d", e :: Maybe Int <?> "f" }
deriving stock (Generic, Show)
deriving (FromJSON, ToJSON) via CustomJSON '[OmitNothingFields] (ViaNamed X)

main :: IO ()
main = do
print $ decode @X "{\"b\": 1, \"d\": 2}"
print $ decode @X "{\"b\": 1, \"d\": 2, \"f\": 3}"
print $ encode X{a = N 1, c = N 2, e = N Nothing}
print $ encode X{a = N 1, c = N 2, e = N (Just 3)}

Just (X {a = N 1, c = N 2, e = N Nothing})
Just (X {a = N 1, c = N 2, e = N (Just 3)})
"{\"b\":1,\"d\":2}"
"{\"b\":1,\"d\":2,\"f\":3}"

?

#haskell #programming #russian

0

05.07.2021

1 ответов

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Maxim Koltsov · Accepted Answer

Maxim Koltsov

Так, я заинтересован

0

05.07.2021

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Data X = X { a :: Int <?> "b"

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