haskell - newbie question

yroslavasako

conv3rsje

$ cat test.hs 

data Data = Data { dString :: String, dFloat :: Float } deriving (Show)



main :: IO 

main = do

  let d = Data "string" 0.1

  putStrLn . show $ d { dString = "new string" }

  putStrLn . show $ d { dFloat = 1.3 }



$ runhaskell test.hs 

Data {dString = "new string", dFloat = 0.1}

Data {dString = "string", dFloat = 1.3}

yroslavasako

f x = x {SomeField = 12}

sergeikozyr

f x = x {SomeField = 12}

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sergeikozyr

data Data = Data { field1 :: Type1, field2 :: Type2, field3 :: Type 3}

e1 = Data { field1 = <inst1>, field2 = <inst2>, field3 = <inst3> }

e2 = e1 { field2 = <inst2'> }

e3 = e1 { field3 = <inst3'> }

  

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sergeikozyr

alfadred

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