Re: naming data sets

[Ben Pfaff]

Ben Pfaff <address@hidden> writes:

> John Darrington <address@hidden> writes:
>
>> On Tue, Jan 24, 2006 at 11:13:00PM -0800, Ben Pfaff wrote:
>>      
>>      > Here's what I'd add to the PSPP language:
>>      >
>>      >         * Some extra syntax on FILE HANDLE for declaring
>>      >           temporary file handles (MODE=TEMPORARY perhaps).
>>      
>>      I dropped this.  There is no need to declare a temporary file
>>      handle in advance.  Instead, any file handle with a name that
>>      begins with $ is a temporary file handle.
>>
>> That makes sense iff the current spss language prohibits file handles
>> which begin with $ --- I don't know if that is the case.
>
> I haven't checked yet, but the manual I have here says "File
> handles must conform to SPSS variable naming rules."  User
> variable names aren't allowed to start with $ so I was making the
> same assumption for file handles.

You know, it occurs to me now that # would be a better prefix
character for a temporary handle, because # is already used for
"scratch variables" have somewhat similar attributes.  Perhaps
I'll use # as the prefix and call them "scratch files" instead?
I like this better than $ and "temporary files".

I thought about the compatibility issue a bit more.  I don't
think it's a problem.  First, scratch files apply only when
"enhanced syntax" is enabled.  Second, correct SPSS syntax will
still work even if it has file handles whose names begin with #,
because explicitly declaring a file handle on FILE HANDLE whose
name begins with # is still allowed (even in enhanced mode).
It's just that if you *don't* declare the name (in enhanced mode)
it's assumed that it's a scratch file.
-- 
"Sanity is not statistical."
--George Orwell