Removing lazy IO? (Was: Re: Proposal: Stop enforcing single-writer-multi-reader file access)

Jason Dagit dagitj at
Wed Nov 9 04:26:46 CET 2011

On Tue, Nov 8, 2011 at 7:02 PM, Ian Lynagh <igloo at> wrote:
> On Tue, Nov 08, 2011 at 01:07:23PM +0000, Duncan Coutts wrote:
>> We should take the same approach with openFile. Currently we have:
>> openFile :: FilePath -> IOMode -> IO Handle
>> I suggest changing the IOMode for a record of options which would
>> include the IO mode (read/write/read-write/etc), and other things like
>> file locking, default create permissions, create exclusive etc. Again,
>> we'd use a default value and override extra options as necessary.
> I've just reread the thread, and I think the best way forwards would be
> to make the original proposed change now, and for the above change to be
> proposed separately.

The other separate proposal that I would like to propose (at some time
in the future) is a thorough removal of "lazy IO" from base.  Or at
least make it not available in the Prelude (ie., people have to ask
for it if they want it).  Perhaps this would require the support of


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