[Haskell-cafe] Re: Writing binary files?
glynn.clements at virgin.net
Thu Sep 16 05:51:46 EDT 2004
Udo Stenzel wrote:
> > > One more reason to fix the I/O functions to handle encodings and have
> > > a seperate/underlying binary I/O API.
> > The problem is that we also need to fix them to handle *no encoding*.
> What are you proposing here? Making the breakage even worse by specifying
> a text based api that uses "no encoding"?
No. I'm suggesting that many of the I/O functions shouldn't be
treating their arguments or return values as text.
> Having a seperate byte based api is far better. If you don't know
> the encoding, all you have is bytes, no text.
My point is that many of the existing functions should be changed to
use bytes instead of text (not separate byte/char versions). E.g.:
type FilePath = [Byte]
If you have a reason to treat a FilePath as text, then you convert it.
names <- getDirectoryContents dir
let namesT = map (toString localeEncoding) names
We don't need a separate getDirectoryContentsAsText, and we certainly
don't want that to be the default.
For stream I/O, then having both text and binary read/write functions
> > > String's are a list of unicode characters, [Word8] is a
> > > list of bytes.
> > And what comes out of (and goes into) most core library functions is
> > the latter.
> So System.Directory needs to be specified in terms of bytes, too. Looks like
> a clean solution to me.
Sure. But I'm looking for a solution which doesn't involve re-writing
everything, and which won't result in lots of programs suddenly
becoming unreliable if the hardwired default ISO-8859-1 conversion is
Glynn Clements <glynn.clements at virgin.net>
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