module Data.String.Extra
(
safeReadFile
, sanitizeLCIdentifier
, sanitizeUCIdentifier
)
where
import Control.Exception ( catch )
import Data.Char ( toLower, toUpper )
import System.IO.Error ( isDoesNotExistError )
safeReadFile :: FilePath -> IO (Either String String)
safeReadFile :: String -> IO (Either String String)
safeReadFile String
fp =
IO (Either String String)
-> (IOError -> IO (Either String String))
-> IO (Either String String)
forall e a. Exception e => IO a -> (e -> IO a) -> IO a
catch (String -> Either String String
forall a. a -> Either String a
forall (m :: * -> *) a. Monad m => a -> m a
return (String -> Either String String)
-> IO String -> IO (Either String String)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> String -> IO String
readFile String
fp) ((IOError -> IO (Either String String))
-> IO (Either String String))
-> (IOError -> IO (Either String String))
-> IO (Either String String)
forall a b. (a -> b) -> a -> b
$ \IOError
e ->
if IOError -> Bool
isDoesNotExistError IOError
e
then Either String String -> IO (Either String String)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (Either String String -> IO (Either String String))
-> Either String String -> IO (Either String String)
forall a b. (a -> b) -> a -> b
$ String -> Either String String
forall a b. a -> Either a b
Left (String -> Either String String) -> String -> Either String String
forall a b. (a -> b) -> a -> b
$ String -> String
strStringFileNotFound String
fp
else Either String String -> IO (Either String String)
forall a. a -> IO a
forall (m :: * -> *) a. Monad m => a -> m a
return (Either String String -> IO (Either String String))
-> Either String String -> IO (Either String String)
forall a b. (a -> b) -> a -> b
$ String -> Either String String
forall a b. a -> Either a b
Left (String -> Either String String) -> String -> Either String String
forall a b. (a -> b) -> a -> b
$ String -> String
strStringCannotOpenFile String
fp
strStringFileNotFound :: FilePath -> String
strStringFileNotFound :: String -> String
strStringFileNotFound String
fp = String
"File not found: " String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
fp
strStringCannotOpenFile :: FilePath -> String
strStringCannotOpenFile :: String -> String
strStringCannotOpenFile String
fp = String
"Error opening file: " String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
fp
sanitizeLCIdentifier :: String -> String
sanitizeLCIdentifier :: String -> String
sanitizeLCIdentifier = String -> String
headToLower (String -> String) -> (String -> String) -> String -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (Char -> Char) -> String -> String
forall a b. (a -> b) -> [a] -> [b]
map Char -> Char
sanitizeCharacter
where
sanitizeCharacter :: Char -> Char
sanitizeCharacter Char
'-' = Char
'_'
sanitizeCharacter Char
x = Char
x
headToLower :: [Char] -> [Char]
headToLower :: String -> String
headToLower [] = []
headToLower (Char
x:String
xs) = Char -> Char
toLower Char
x Char -> String -> String
forall a. a -> [a] -> [a]
: String
xs
sanitizeUCIdentifier :: String -> String
sanitizeUCIdentifier :: String -> String
sanitizeUCIdentifier = String -> String
headToUpper (String -> String) -> (String -> String) -> String -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (Char -> Char) -> String -> String
forall a b. (a -> b) -> [a] -> [b]
map Char -> Char
sanitizeCharacter
where
sanitizeCharacter :: Char -> Char
sanitizeCharacter Char
'-' = Char
'_'
sanitizeCharacter Char
x = Char
x
headToUpper :: [Char] -> [Char]
headToUpper :: String -> String
headToUpper [] = []
headToUpper (Char
x:String
xs) = Char -> Char
toUpper Char
x Char -> String -> String
forall a. a -> [a] -> [a]
: String
xs