Hi Olivier,
you wrote:
>Do you think that %"" should be accepted as a valid filename ?
>Personnally I don't think so, because no operating system I know accept
>that.
>%"" should return <none>.
>This would solve many issues with filename handling (split-path,
>clean-path).
A valid filename and a valid file! datatype are completely different
concepts. A file! datatype is just a sort of string, and whether that
can serve as a valid filename is not something REBOL should have to
worry about. How about this?
>> nasty-file: to file! {echo "clobber" > rebol.exe}
== %echo%20%22clobber%22%20>%20rebol.exe
>> write nasty-file "I did it"
** Access Error: Cannot open /C/temp/echo "clobber" > rebol.exe.
** Where: write nasty-file "I did it"
It's the operating system that decides whether to allow a filename or not.
%"" by itself is not very useful, but how about this:
>> prefix: %X-
== %X-
>> join prefix %name.ext
== %X-name.ext
>> prefix: %""
== %
>> join prefix %name.ext
== %name.ext
Even a value that by itself is not a valid filename can make sense in
combination with another value.
>Another related problem:
>>> to file! none
>== %none
>
>It should return either the none value (of datatype none!) or %"" (depending
>on your answer to the previous question).
This behavior can be annoying, but it's fairly consistent. Compare:
>> join "a string: " none
== "a string: none"
>> head insert ", a string" true
== "true, a string"
>> to issue! file!
== #file
Your idea of having TO FILE! NONE return the value NONE is not a good idea.
TO always returns a value belonging to the datatype specified in its first
argument (or if that's not possible, an error is produced). To have TO
return various other datatypes depending on the circumstance would make
REBOL much more inconsistent.
Your idea of having TO FILE! NONE return the value %"" makes a lot of sense,
but still, what will you do with TRUE, FALSE, or datatypes? It's not always
obvious what is the most reasonable value. I personally find the present
behavior the best. I never intend to convert NONE to a file! , so when
I do and I see a file name like %abcnone.xyz it's a dead giveaway what
went wrong. If I just got %abc.xyz and that wasn't what I was expecting,
it'd be a lot harder to track down the problem.
See you,
Eric
