Read in Haskell

In Haskell, we can read files using the readFile function from the System.IO module. Here is an example of how to use this function:

import System.IO
main = do

  fileHandle <- readFile "example.txt"

  putStrLn fileHandle

In this example, we have imported the System.IO module and defined a main function. Within the main function, we call the readFile function and pass it the name of the file we want to read ("example.txt"). The readFile function returns a string containing the contents of the file, which we store in the fileHandle variable.

Finally, we use the putStrLn function to print the contents of the file to the console.

Here is another example that shows how to read a file line by line:

import System.IO
main = do

  fileHandle <- openFile "example.txt" ReadMode

  contents <- hGetContents fileHandle

  let linesOfFile = lines contents

  mapM_ putStrLn linesOfFile

  hClose fileHandle

In this example, we use the openFile function to open the file in read mode, which returns a file handle. We then call the hGetContents function, passing it the file handle, to retrieve the contents of the file as a string.

We can use the lines function to split the contents into a list of strings, with each string representing a line in the file. We then use the mapM_ function to print each line to the console, followed by the hClose function to close the file handle.

These are just a couple of examples of how to read a file in Haskell using the System.IO module.