Update Data in Files in Haskell

Question

i am learning about CRUD in haskell, but i get confuse to update data. so far this i have made, this is my data type

data ProjAdmin = RecordProjAdmin { projname :: String, animator :: String,
                             projstatus :: String} deriving (Show, Read)

this is data sample

thisData :: [ProjAdmin]
thisData = [RecordProjAdmin {projname = "SERIAL", animator = "jet juy", projstatus = "ongoing"},
           RecordProjAdmin {projname = "FIILER", animator = "jet juy", projstatus = "done"},
           RecordProjAdmin {projname = "RECYCLE-TVS", animator = "jet juy", projstatus = "done"}]

the logic here is, i want to change projname = "SERIAL" from "ongoing" status to "done", so next time i will set getLine input name "SERIAL". i still bit confuse to doing this either

filTering :: [ProjAdmin]->[ProjAdmin]
filTering = filter(\s-> projstatus s == "ongoing")

this is my main

main ::IO ()
main  = do
         let output = filTering thisData
         let changedata = map (\y -> if projstatus y=="ongoing" then projstatus y = "done" else projstatus y) output
         print changedata

if there's is any idea to create update function, i'll be so greatfull thank you so much, or is it possible to using monad transformer to doing this? or if you know post that already answer or web link please let me know

thank you before

Answer 1

You're pretty close! Here's a corrected version of the incorrect line:

let changedata = map (\y -> if projstatus y == "ongoing" then y { projstatus = "done" } else y) output

For your Googling pleasure, this is called "record update syntax".