[clean-list] Wish list =+ New *World

[Andrew Butterfield]

Edsko de Vries wrote:
> On Thu, Aug 23, 2007 at 08:16:55AM -0700, Shivkumar Chandrasekaran wrote:
>> But this still requires that an extra *File parameter be threaded  
>> down from Start to the local call site. I still don't see why we  
>> couldn't (well I guess I could using C functions?) have a  
>> createFiles :: *Files call that returns a blank nameless partition  
>> from the FileSystem? This would be very convenient for any systems  
>> programming task requiring functional access to /tmp......
> 
> Yes, I guess if you can guarantee that that the *Files you get is
> pointing to an 'empty partition', you're safe. But I wouldn't be too
> sure how to implement that.

The file-system implementation in Clean would have to
manage such a invisible (not empty) partition, and ensure that it
was not observable by file/directory accesses coming from other parts
of the program.

For example, if such a partition was implemented as /tmp/invisible123 
(say), then if someone using a Clean program directory dialogue actaully
went at looked at /tmp, then the directory invisible123 would not show 
up - if it did, then the Clean program would lose referential transparency.

In other words a sort of "visibility layer" would have to reside between
the Clean File access API and the underlying OS file API.


> 
> Edsko
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