System.IO.StringLike.Impl

The classes in this library roughly encapulates things you can read or write through a "handle", typically writing something "string like" to a file, but the interface is very flexible.

Currently only String, ByteString and Text in their strict/lazy varieties and builders are implemented.

However, the interface has the flexibility to write non-character data. For example an implementation for a [Int] could just write all the Ints in binary to the file and read them back into a [Int].

Also the interface can be defined for "handles" other than standard files. Currently the only such instance that does not use Handle is for hGetContents, where one can call directly:

hGetContents fileName

In this case, "handle" is a FilePath.

The initial motivation of to avoid having to change all your function calls if you change your string type, but it's actually more general than that now.

The point of this library is to be able to read and write raw data to the disk (and perhaps other places) quickly without thinking too much about it.

It's not intended to be a replacement for say Binary. It's intended to be lower level. Binary internally creates lazy bytestrings for the user to write to the disk, this library is instead just about directly writing raw data.

Note that we currently only have classes for

Most of the functions should be fairly self explanatory having the same meaning as in Prelude or System.IO but more general.

Documentation

type CanGetContents t = CanGetContentsClass IO Handle t

Type synonym, for the common case of an ordinary Handle in the IO.

class Monad m => CanGetContentsClass m handleT t where

Methods

hGetContents :: handleT -> m t

Generalised hGetContents

hGetContents :: (CanProxyFrom t, CanGetContentsClass m handleT (CanProxyT t)) => handleT -> m t

Generalised hGetContents

Instances

(Monad m, CanGetContentsClass m Handle Text) => CanGetContentsClass m Handle Builder

Methods

hGetContents :: Handle -> m Builder

(~) (* -> *) m IO => CanGetContentsClass m Handle Text

Methods

hGetContents :: Handle -> m Text

(~) (* -> *) m IO => CanGetContentsClass m Handle Text

Methods

hGetContents :: Handle -> m Text

(Monad m, CanGetContentsClass m Handle ByteString) => CanGetContentsClass m Handle Builder

Methods

hGetContents :: Handle -> m Builder

(~) (* -> *) m IO => CanGetContentsClass m Handle ByteString

Methods

hGetContents :: Handle -> m ByteString

(~) (* -> *) m IO => CanGetContentsClass m Handle ByteString

Methods

hGetContents :: Handle -> m ByteString

(~) (* -> *) m IO => CanGetContentsClass m Handle String

Methods

hGetContents :: Handle -> m String

((~) (* -> *) m IO, CanGetContentsClass m Handle t) => CanGetContentsClass m FilePath t

Methods

hGetContents :: FilePath -> m t

getContents :: CanGetContents t => IO t

readFile :: CanGetContents t => FilePath -> IO t

type CanGetLine t = CanGetLineClass IO Handle t

Type synonym for CanGetLineClass. See CanGetContents for more details.

class CanGetContentsClass m handleT t => CanGetLineClass m handleT t where

Methods

hGetLine :: handleT -> m t

Generalised hGetLine

hGetLine :: (CanProxyFrom t, CanGetLineClass m handleT (CanProxyT t)) => handleT -> m t

Generalised hGetLine

Instances

CanGetLineClass m Handle Text => CanGetLineClass m Handle Builder

Methods

hGetLine :: Handle -> m Builder

(~) (* -> *) m IO => CanGetLineClass m Handle Text

Methods

hGetLine :: Handle -> m Text

(~) (* -> *) m IO => CanGetLineClass m Handle Text

Methods

hGetLine :: Handle -> m Text

CanGetLineClass m Handle ByteString => CanGetLineClass m Handle Builder

Methods

hGetLine :: Handle -> m Builder

(~) (* -> *) m IO => CanGetLineClass m Handle ByteString

Methods

hGetLine :: Handle -> m ByteString

(~) (* -> *) m IO => CanGetLineClass m Handle ByteString

Methods

hGetLine :: Handle -> m ByteString

(~) (* -> *) m IO => CanGetLineClass m Handle String

Methods

hGetLine :: Handle -> m String

getLine :: CanGetLine t => IO t

type CanPutStr t = CanPutStrClass IO Handle t

Type synonym for CanPutStrClass. See CanGetContents for more details.

class Monad m => CanPutStrClass m handleT t where

Methods

hPutStr :: handleT -> t -> m ()

Generalised hPutStr

hPutStr :: (CanProxyTo t, CanPutStrClass m handleT (CanProxyT t)) => handleT -> t -> m ()

Generalised hPutStr

Instances

(Monad m, CanPutStrClass m Handle Text) => CanPutStrClass m Handle Builder

Methods

hPutStr :: Handle -> Builder -> m ()

(~) (* -> *) m IO => CanPutStrClass m Handle Text

Methods

hPutStr :: Handle -> Text -> m ()

(~) (* -> *) m IO => CanPutStrClass m Handle Text

Methods

hPutStr :: Handle -> Text -> m ()

(~) (* -> *) m IO => CanPutStrClass m Handle Builder

Methods

hPutStr :: Handle -> Builder -> m ()

(~) (* -> *) m IO => CanPutStrClass m Handle ByteString

Methods

hPutStr :: Handle -> ByteString -> m ()

(~) (* -> *) m IO => CanPutStrClass m Handle ByteString

Methods

hPutStr :: Handle -> ByteString -> m ()

(~) (* -> *) m IO => CanPutStrClass m Handle String

Methods

hPutStr :: Handle -> String -> m ()

((~) (* -> *) m IO, CanPutStrClass m Handle t) => CanPutStrClass m FilePath t

Methods

hPutStr :: FilePath -> t -> m ()

putStr :: CanPutStr t => t -> IO ()

writeFile :: CanPutStr t => FilePath -> t -> IO ()

appendFile :: CanPutStr t => FilePath -> t -> IO ()

interact :: (CanGetContents t, CanPutStr t) => (t -> t) -> IO ()

type CanPutStrLn t = CanPutStrLnClass IO Handle t

Effective type synonym for CanPutStrLnClass. See CanGetContents for more details.

class CanPutStrClass m handleT t => CanPutStrLnClass m handleT t where

Methods

hPutStrLn :: handleT -> t -> m ()

Generalised hPutStrLn

hPutStrLn :: (CanProxyTo t, CanPutStrLnClass m handleT (CanProxyT t)) => handleT -> t -> m ()

Generalised hPutStrLn

Instances

CanPutStrLnClass m Handle Text => CanPutStrLnClass m Handle Builder

Methods

hPutStrLn :: Handle -> Builder -> m ()

(~) (* -> *) m IO => CanPutStrLnClass m Handle Text

Methods

hPutStrLn :: Handle -> Text -> m ()

(~) (* -> *) m IO => CanPutStrLnClass m Handle Text

Methods

hPutStrLn :: Handle -> Text -> m ()

CanPutStrClass m Handle Builder => CanPutStrLnClass m Handle Builder

Methods

hPutStrLn :: Handle -> Builder -> m ()

(~) (* -> *) m IO => CanPutStrLnClass m Handle ByteString

Methods

hPutStrLn :: Handle -> ByteString -> m ()

(~) (* -> *) m IO => CanPutStrLnClass m Handle ByteString

Methods

hPutStrLn :: Handle -> ByteString -> m ()

(~) (* -> *) m IO => CanPutStrLnClass m Handle String

Methods

hPutStrLn :: Handle -> String -> m ()

putStrLn :: CanPutStrLn t => t -> IO ()

type family CanProxyT t

If you have a data structure where in many cases the simplest way to read or write to it is just convert it to another you should define an instance of this class.

For example, the simple way to write ByteString Builders is just to convert them to and from lazy ByteStrings.

Defining classese CanProxyTo and CanProxyFrom will define default methods for many of the other classes in this library. These can still be overriden if desired but it will save you a lot of boilerplate if you just which to convert your structure through some other.

Instances

type CanProxyT Builder

type CanProxyT Builder = ByteString

type CanProxyT Builder

type CanProxyT Builder = Text

class CanProxyTo t where

Minimal complete definition

canProxyTo

Methods

canProxyTo :: t -> CanProxyT t

How to convert to the type you will attempt to store

Instances

CanProxyTo Builder

Methods

canProxyTo :: Builder -> CanProxyT Builder

CanProxyTo Builder

Methods

canProxyTo :: Builder -> CanProxyT Builder

class CanProxyFrom t where

Minimal complete definition

canProxyFrom

Methods

canProxyFrom :: CanProxyT t -> t

How to convert from the type you will attempt to store

Instances

CanProxyFrom Builder

Methods

canProxyFrom :: CanProxyT Builder -> Builder

CanProxyFrom Builder

Methods

canProxyFrom :: CanProxyT Builder -> Builder