* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
[not found] ` <E1ZTaib-0004Wz-Ih@vcs.savannah.gnu.org>
@ 2015-08-24 13:37 ` Stefan Monnier
2015-08-24 13:51 ` Nicolas Petton
0 siblings, 1 reply; 7+ messages in thread
From: Stefan Monnier @ 2015-08-24 13:37 UTC (permalink / raw)
To: emacs-devel; +Cc: Nicolas Petton
> Remove the calls to `seq-into` from `seq-concatenate`
> Since most new types of seq would have to be defined as sequences (cons
> cells or CL structs, mostly), there is no need to convert the seqs to
> sequences (which can be a fairly expensive operation).
I don't understand this change. Can't it cause two CL-structs to be
vconcat'd together, which wouldn't make much sense?
Stefan
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
2015-08-24 13:37 ` [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate` Stefan Monnier
@ 2015-08-24 13:51 ` Nicolas Petton
2015-08-24 19:23 ` Stefan Monnier
0 siblings, 1 reply; 7+ messages in thread
From: Nicolas Petton @ 2015-08-24 13:51 UTC (permalink / raw)
To: Stefan Monnier, emacs-devel
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Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> Remove the calls to `seq-into` from `seq-concatenate`
>> Since most new types of seq would have to be defined as sequences (cons
>> cells or CL structs, mostly), there is no need to convert the seqs to
>> sequences (which can be a fairly expensive operation).
>
> I don't understand this change. Can't it cause two CL-structs to be
> vconcat'd together, which wouldn't make much sense?
The previous version of `seq-concatenate' did not prevent that, since
CL-structs are vectors, thus sequences, and the function was using
`sequencep' to determine if the seq had to be converted or not.
Nico
--
Nicolas Petton
http://nicolas-petton.fr
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
2015-08-24 13:51 ` Nicolas Petton
@ 2015-08-24 19:23 ` Stefan Monnier
2015-08-25 8:32 ` Nicolas Petton
0 siblings, 1 reply; 7+ messages in thread
From: Stefan Monnier @ 2015-08-24 19:23 UTC (permalink / raw)
To: Nicolas Petton; +Cc: emacs-devel
>> I don't understand this change. Can't it cause two CL-structs to be
>> vconcat'd together, which wouldn't make much sense?
> The previous version of `seq-concatenate' did not prevent that, since
> CL-structs are vectors, thus sequences, and the function was using
> `sequencep' to determine if the seq had to be converted or not.
Indeed, but if we intend to work for new "sequence" types defined via
CL-struct, that's still a problem.
Stefan
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
2015-08-24 19:23 ` Stefan Monnier
@ 2015-08-25 8:32 ` Nicolas Petton
2015-08-25 14:30 ` Stefan Monnier
0 siblings, 1 reply; 7+ messages in thread
From: Nicolas Petton @ 2015-08-25 8:32 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
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Stefan Monnier <monnier@iro.umontreal.ca> writes:
>>> I don't understand this change. Can't it cause two CL-structs to be
>>> vconcat'd together, which wouldn't make much sense?
>> The previous version of `seq-concatenate' did not prevent that, since
>> CL-structs are vectors, thus sequences, and the function was using
>> `sequencep' to determine if the seq had to be converted or not.
>
> Indeed, but if we intend to work for new "sequence" types defined via
> CL-struct, that's still a problem.
Yes, it is still a problem. One solution would be to test if the seq is
a cl-struct with, in which case we could use `seq-into'. But then that
would only fix the cl-struct case, not any other.
Nico
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
2015-08-25 8:32 ` Nicolas Petton
@ 2015-08-25 14:30 ` Stefan Monnier
2015-08-25 14:48 ` Nicolas Petton
0 siblings, 1 reply; 7+ messages in thread
From: Stefan Monnier @ 2015-08-25 14:30 UTC (permalink / raw)
To: Nicolas Petton; +Cc: emacs-devel
> Yes, it is still a problem. One solution would be to test if the seq is
> a cl-struct with, in which case we could use `seq-into'. But then that
> would only fix the cl-struct case, not any other.
If we make it into a defmethod, at least it would be possible for
specific cl-structs to fix the problem.
Stefan
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
2015-08-25 14:30 ` Stefan Monnier
@ 2015-08-25 14:48 ` Nicolas Petton
2015-08-25 21:52 ` Stefan Monnier
0 siblings, 1 reply; 7+ messages in thread
From: Nicolas Petton @ 2015-08-25 14:48 UTC (permalink / raw)
To: Stefan Monnier; +Cc: emacs-devel
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Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> Yes, it is still a problem. One solution would be to test if the seq is
>> a cl-struct with, in which case we could use `seq-into'. But then that
>> would only fix the cl-struct case, not any other.
>
> If we make it into a defmethod, at least it would be possible for
> specific cl-structs to fix the problem.
It is already, or did you mean something else? But how would you do it
here? There can be any number of sequences.
Nico
--
Nicolas Petton
http://nicolas-petton.fr
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate`
2015-08-25 14:48 ` Nicolas Petton
@ 2015-08-25 21:52 ` Stefan Monnier
0 siblings, 0 replies; 7+ messages in thread
From: Stefan Monnier @ 2015-08-25 21:52 UTC (permalink / raw)
To: Nicolas Petton; +Cc: emacs-devel
>>> Yes, it is still a problem. One solution would be to test if the seq is
>>> a cl-struct with, in which case we could use `seq-into'. But then that
>>> would only fix the cl-struct case, not any other.
>> If we make it into a defmethod, at least it would be possible for
>> specific cl-structs to fix the problem.
> It is already, or did you mean something else? But how would you do it
> here? There can be any number of sequences.
That's exactly the issue: it needs to be structured so that callers can
usefully override it.
As it is currently defined, the only overriding possible is to provide
new valid values for the `type' argument.
So its default definition should make use of seq-into or something
similar so that new types can provide their own implementation.
E.g., you could define a new
(cl-defgeneric seq-into-sequence (seq)
(if (sequencep seq) seq
(error "Don't know how to turn %S into a sequence" seq)))
and then
(cl-defgeneric seq-concatenate (type &rest seqs)
(apply #'cl-concatenate type (mapcar #'seq-into-sequence seqs)))
Stefan
^ permalink raw reply [flat|nested] 7+ messages in thread
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[not found] ` <E1ZTaib-0004Wz-Ih@vcs.savannah.gnu.org>
2015-08-24 13:37 ` [Emacs-diffs] master c13a4df: Remove the calls to `seq-into` from `seq-concatenate` Stefan Monnier
2015-08-24 13:51 ` Nicolas Petton
2015-08-24 19:23 ` Stefan Monnier
2015-08-25 8:32 ` Nicolas Petton
2015-08-25 14:30 ` Stefan Monnier
2015-08-25 14:48 ` Nicolas Petton
2015-08-25 21:52 ` Stefan Monnier
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