tcl-core

[TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Jan N. <jan...@gm...>]

In 7 places in the core I find calls like:
     (void) Tcl_GetStringResult(interp)
but interp->result is not used afterwards. I'm
refering to tclBasic.c (6) and tclHistory.c (1).

Shouldn't these calls have been removed as part
of the TIP #330 implementation? If extensions
are not allowed any more to access interp->result
directly, then those calss serve no purpose other than
slowing down Tcl. It might break extensions which still
use interp->result, but due to TIP #330, that's exactly
what users of Tcl 8.6 should expect.

Regards,
         Jan Nijtmans

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Donald G P. <dg...@ni...>]

Jan Nijtmans wrote:
> In 7 places in the core I find calls like:
>      (void) Tcl_GetStringResult(interp)
> but interp->result is not used afterwards. I'm
> refering to tclBasic.c (6) and tclHistory.c (1).
> 
> Shouldn't these calls have been removed as part
> of the TIP #330 implementation? 

No.  TIP 330 called for #define USE_INTERP_RESULT
to permit one last path of reprieve for direct access
to interp->result.  Such code needs to remain present
to make that mode work.

-- 
| Don Porter          Mathematical and Computational Sciences Division |
| don...@ni...             Information Technology Laboratory |
| http://math.nist.gov/~DPorter/                                  NIST |
|______________________________________________________________________|

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Kevin K. <ke...@ac...>]

Jan Nijtmans wrote:
> In 7 places in the core I find calls like:
>      (void) Tcl_GetStringResult(interp)
> but interp->result is not used afterwards. I'm
> refering to tclBasic.c (6) and tclHistory.c (1).
> 
> Shouldn't these calls have been removed as part
> of the TIP #330 implementation? If extensions
> are not allowed any more to access interp->result
> directly, then those calss serve no purpose other than
> slowing down Tcl. It might break extensions which still
> use interp->result, but due to TIP #330, that's exactly
> what users of Tcl 8.6 should expect.

If we had made the Tcl_Interp data structure opaque in
8.5, I'd agree with you wholeheartedly.  We've moved too slowly
on this, and been too quiet about the initial warnings.
Since we didn't vote to take out interp->result altogether,
I'm a little nervous about taking out the code that makes
it useful, particularly since there's not much field
experience left (unless Andreas has reported something
that I've missed) about what this does to currently fielded
extensions. (He maintains the largest extension distribution
that I'm aware of.) Andreas, have you tried building the
AT extension set against 8.6-post-TIP#330?

-- 
73 de ke9tv/2, Kevin

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Donald G P. <dg...@ni...>]

Kevin Kenny wrote:
> it useful, particularly since there's not much field
> experience left (unless Andreas has reported something
> that I've missed) about what this does to currently fielded
> extensions. (He maintains the largest extension distribution
> that I'm aware of.) Andreas, have you tried building the
> AT extension set against 8.6-post-TIP#330?

Relevant to this is the message from Adam Williamson several days ago
reporting Tcl package updates for 8.6 for Mandriva:

https://sourceforge.net/mailarchive/message.php?msg_id=1228554157.29250.12.camel%40lenovo.local.net

-- 
| Don Porter          Mathematical and Computational Sciences Division |
| don...@ni...             Information Technology Laboratory |
| http://math.nist.gov/~DPorter/                                  NIST |
|______________________________________________________________________|

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Jan N. <jan...@gm...>]

2008/12/16 Donald G Porter <dg...@ni...>:
> Relevant to this is the message from Adam Williamson several days ago
> reporting Tcl package updates for 8.6 for Mandriva:
>
> https://sourceforge.net/mailarchive/message.php?msg_id=1228554157.29250.12.camel%40lenovo.local.net

OK. Looks too dangerous to do it now, but it definitely should be
considered in a future Tcl version. (In my view it doesn't need to wait
for Tcl 9, but others might disagree on that)

Regards,
          Jan Nijtmans

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Donald G P. <dg...@ni...>]

Jan Nijtmans wrote:
> OK. Looks too dangerous to do it now, but it definitely should be
> considered in a future Tcl version. (In my view it doesn't need to wait
> for Tcl 9, but others might disagree on that)

And others might disagree that Tcl 9 is something we will be waiting 
for. :):):)

-- 
| Don Porter          Mathematical and Computational Sciences Division |
| don...@ni...             Information Technology Laboratory |
| http://math.nist.gov/~DPorter/                                  NIST |
|______________________________________________________________________|

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Alexandre F. <ale...@gm...>]

On Tue, Dec 16, 2008 at 4:48 PM, Donald G Porter <dg...@ni...> wrote:
>
> And others might disagree that Tcl 9 is something we will be waiting
> for. :):):)

Indeed :)

I'd be happy with a Tcl freezing in 8.x, without a new quantum leap.
And then rule for 1000 years. Just like the Bourne Shell has been
frozen for eons, and will rule longer than mankind.

-Alex

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Jan N. <jan...@gm...>]

2008/12/16 Alexandre Ferrieux <ale...@gm...>:
> I'd be happy with a Tcl freezing in 8.x, without a new quantum leap.
> And then rule for 1000 years. Just like the Bourne Shell has been
> frozen for eons, and will rule longer than mankind.

Then how do you explain the existance of
bash (Bourne Again Shell?)  .....  ;-)

(I shouldn't continue this discussion, just couldn't
resist answering that.......I don't really expect an answer..)

Regards,
         Jan Nijtmans

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Adam W. <awi...@ma...>]

On Tue, 2008-12-16 at 11:49 +0100, Jan Nijtmans wrote:
> In 7 places in the core I find calls like:
>      (void) Tcl_GetStringResult(interp)
> but interp->result is not used afterwards. I'm
> refering to tclBasic.c (6) and tclHistory.c (1).
> 
> Shouldn't these calls have been removed as part
> of the TIP #330 implementation? If extensions
> are not allowed any more to access interp->result
> directly, then those calss serve no purpose other than
> slowing down Tcl. It might break extensions which still
> use interp->result, but due to TIP #330, that's exactly
> what users of Tcl 8.6 should expect.

(after writing this i see that DGP already did, but to add weight, I'll
send it anyway).

FWIW, I'm against this. The current state of #330 is that 8.6 explicitly
allows a 'hack' to re-enable interp->result, as a transitional measure,
and it is stated that 9.0 will remove any possibility to use
interp->result. Thus changes that would break the use of interp->result
should only be done in 9.0, not 8.6.

In practical terms, for the Mandriva 8.6 migration, I could not properly
fix some obscure Tcl packages not to use interp->result, not being a
strong enough coder, so I had to use the hack to re-enable it for those
packages. If it stops working it'd cause me rather a bit of
inconvenience as I have to either a) learn enough to fix that code
myself or b) find someone else to do it. I was rather counting on having
the time until the 9.0 release to do that, not having to try and get it
done for 8.6.
-- 
adamw

Re: [TCLCORE] TIP #330 and (void) Tcl_GetStringResult(interp) calls in the core.

[Jan N. <jan...@gm...>]

2008/12/24 Adam Williamson <awi...@ma...>:
> FWIW, I'm against this. The current state of #330 is that 8.6 explicitly
> allows a 'hack' to re-enable interp->result, as a transitional measure,
> and it is stated that 9.0 will remove any possibility to use
> interp->result. Thus changes that would break the use of interp->result
> should only be done in 9.0, not 8.6.

Don´t worry! The reactions convinced me of the same. However,
in the mean time I was thinking about a better way to keep the
current contract, and still improve the curent duality between
interp->result and interp->objResult.

This idea, in short, is a new object type "dstring", which
is nothing more than a DString wrapped in an object. We can
simply change Tcl_GetStringResult() such that it modifies the
current objResult type to be a "dstring". Then we simply
let interp->result point to de dstring of interp->objResult and
the two versions point to the same. It would simplyfy a lot
other functions as well, like Tcl_AppendResult or
Tcl_ObjPrintf, and it can be made such that all StringResult
functions keep the current behavior, only it prevents the
constant conversion between string and Tcl_Obj.

Anyway, it's just an idea that has to be worked out further,
maybe for Tcl 8.7 (maybe not).

Regards,
          Jan Nijtmans