On Saturday, 28 December 2013 at 08:18:44 UTC, Jonathan M Davis
wrote:
on it specifically. My main point was that some stuff in
std.file is system-
specific and that if it has to be, it's better to have it in
std.file as system-
specific rather than not having it at all just because it
couldn't be
completely cross-platform and portable. So, just because
setFileAttributes is
doing something system-specific does not mean that it's bad.
It is bad. If you want system-specific behaviour you should have
a separate interface that provide all the advantages that going
to a lower level provides. Having half-assed OS-specific support
is too pragmatic and will lead to a legacy mess in the long run
when those interfaces become obsolete.
A good file abstraction should also support newer file systems
like Google Cloud Storage, though. GCS does not support append()
or directories.
A good file abstraction should also provide mechanisms to deal
with different levels of consistency on the underlying filesystem
and caching-mechanism:
- read after write might return an old version
- read after write returns the new version if read from the same
computer
- read after write always returns the new version
As a new language D should support Cloud based environments
out-of-the-box with a hierarchy of functionality down to the
peculiarities of Windows/Posix etc so that you can decide to code
in a manner that supports all platforms without having to litter
your code with ifs and version-statements… and also restrict you
to the subset you have "authorized" so that you can develop on
your Windows system and port it to the cloud with just a
recompile without knowing the details of the cloud file system.
(i.e. the compiler warns you when you are using system specific
functionality).
I also think good file system support implies built-in caching
and let the library decide whether to turn library-level caching
on or off based on what the operating system or underlying
interface supports. E.g. the ability to tell the system that you
want successive reads of a file to be available fast at the cost
of consistency.
