Dear Jürgen,

Thank you for your response.  Implementing 11⎕CR and 12⎕CR would be very
helpful.

I still need an answer to question 3 if you can.

Thanks!

Blake



On Sat, Apr 19, 2014 at 8:05 AM, Juergen Sauermann <
[email protected]> wrote:

> Hi Blake,
>
> 3 ⎕TF produces a byte vector in the CDR (common data representation)
> format defined by IBM.
> It was a by-product  of the CDR format which is used internally in GNU APL
> for communication
> with shared variables and other running GNU APL workspaces. Right now
> there is no inverse
> function for 3 ⎕TF at APL level even though CDR decoding end encoding is
> implemented
> (with the exception of the "progression" type that does not occur in GNU
> APL).
>
> I could add these functions but I would use dyadic ⎕CR rather than ⎕TF
> because that lets you
> work with the values rather than variable names. That is, instead of
> "var←value ◊ 3 ⎕TF 'var'"
> you could do eg. "11⎕CR value" directly and 12⎕CR to convert back.
>
> There is also a similar format called "SCAR" which seems to be supported
> by other APL interpreters
> for exchanging data. I am looking forward to implement that as well, but I
> am currently lacking
> some more information about it.
>
> /// Jürgen
>
>
>
> On 04/19/2014 12:16 PM, Blake McBride wrote:
>
>> Greetings,
>>
>> Now that the wonderful SQL interface is working for me, I believe I can
>> create a component and keyed file system in straight APL easily.  I just
>> need to understand ⎕TF a bit better.
>>
>> 1.  3 ⎕TF seems to produce a string vector representation of an arbitrary
>> nested array without retaining the specific name of the variable.  Is this
>> true?  (If so, this is exactly what I need!)
>>
>> 2.  How can I reverse the process?  i.e. if X holds the result of a 3
>> ⎕TF, I need a way of converting it back to an APL (possibly nested) array
>> that is exactly the same array.  i.e.:
>>
>> x←(5 5⍴⍳25) 'Hello there'
>> y←3⎕TF'x'
>> z←??????????
>>
>> I need to know what ?????? is so that x and z have the exactly equivalent
>> arrays.
>>
>> 3.  I am a little concerned that the vector produced by 3 ⎕TF may have
>> trouble going to and from an SQL VARCHAR using the existing (and
>> fantastic!) library.  I am not sure, but there may be a problem with C null
>> characters ('\0') or other non-printable characters.  Some feedback on this
>> would be very helpful.
>>
>> I suppose I can achieve the same effect by using 2⎕TF and then dropping
>> the assignment part before executing the string.  This should be highly
>> portable but I'd guess less efficient.  Thoughts?
>>
>> Thanks a lot!!
>>
>> Blake
>>
>>
>

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