CODEWITHSUNDEEP
haskell
BarneyL. BarStin
BarneyL. BarStin

Reputation: 343

My haskell code have error to openFile with haskell

Im beginner and im trying to read files of a folder calles "papers"(you can see the tree of my project in the attached file). Im using this code for do it: enter image description here

module LeerDocumentos2 where
import System.Directory
import System.IO.Unsafe
import System.IO()
import Documento


reader :: IO [Documento]
reader = do
    setCurrentDirectory "papers"
    directorio <- getCurrentDirectory
    putStrLn directorio       -- Directorio donde estan los documentos
    pathFicheros <- getDirectoryContents directorio
    printAll pathFicheros
    return (leerDocumentos pathFicheros)
printAll xs = if null xs        -- If the list is empty
        then return ()              -- then we're done, so we quit.
        else do print (head xs)     -- Otherwise, print the first element
                printAll (tail xs)  -- then print all the other elements.

leerDocumentos :: [FilePath] -> [Documento]
leerDocumentos [] = []
leerDocumentos (x:xs) = do
                    let documento = unsafePerformIO (leerDocumento x)
                    [documento]++ leerDocumentos xs
leerDocumento :: String -> IO Documento
leerDocumento ruta = do
                putStrLn ruta
                texto <- readFile ruta
                let docuAux = lines texto
                let revista = obtenerRevista docuAux
                let idd = obtenerID docuAux
                let anno = obtenerAnno docuAux
                let titulo = obtenerTitulo docuAux
                let resumen = obtenerResumen docuAux
                let secciones = obtenerSecciones docuAux
                let documento = D (revista,idd,anno,titulo,resumen,secciones)
                return documento

obtenerRevista :: [String] -> String
obtenerRevista [] = []
obtenerRevista texto = head texto

obtenerID:: [String] -> String
obtenerID [] = []
obtenerID texto =  head (drop 1 (texto))

obtenerAnno:: [String] -> String
obtenerAnno [] = []
obtenerAnno texto =  head (drop 2 (texto))

obtenerTitulo:: [String] -> String
obtenerTitulo [] = []
obtenerTitulo texto =  head (drop 4 (texto))

obtenerResumen:: [String] -> String
obtenerResumen [] = []
obtenerResumen texto =  head (drop 6 (texto))

obtenerSecciones :: [String]->[String]
obtenerSecciones [] = []
obtenerSecciones texto = quitarSeparador (drop 8 (texto))

quitarSeparador :: [String] -> [String]
quitarSeparador [] = []
quitarSeparador (s:sn) = if s == "--" || length s <= 1 then --Para quitar lineas blancas
                            quitarSeparador sn
                          else
                            s:quitarSeparador sn

but im having the next error:

*** Exception: .: openFile: inappropriate type (is a directory)

Someone can help me please?

Upvotes: 0

Views: 241

Answers (1)

ErikR
ErikR

Reputation: 52039

Again, don't use unsafePerformIO.

I bet your problem is that getDirectoryContents returns . and .. which are directories.

At the very least I would filter those out. If the directory has any sub-directories you will also need to filter those out.

Also, I would become familiar with Control.Monad. Try something like this:

import Control.Monad (forM)
import Data.List  (isPrefixOf)

reader = do setCurrentDirectory ...
            paths <- getDirectoryContents dir
            let files = filter (not . isPrefixOf ".") paths
            forM files $ \file -> do
              putStrLn $ "processing " ++ file
              leerDocumento file

Now you can get rid of unsafePerformIO and leerDocumentos.

Upvotes: 2

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