On Thu, 2 Dec 2010, Ben Hyde wrote:
> On Dec 2, 2010, at 4:38 PM, David Owen wrote:
>> Perhaps you are looking for WITH-ACCESSORS?
>
> Indeed, I'm delighted to discover there is something in the language
> I've not used. thanks!
>
> Further I didn't know that setq turns into setf with the help o
On Dec 2, 2010, at 4:38 PM, David Owen wrote:
> On Thu, 2 Dec 2010, Ben Hyde wrote:
>> Anyhow. Recall that with-slots expands to slot-value. That leads
>> me to wonder. Given that with-slots and slot-value are couple, why
>> haven't I observed analogous couple (with-fields and field-value
>> say
On Thu, 2 Dec 2010, Ben Hyde wrote:
> Anyhow. Recall that with-slots expands to slot-value. That leads
> me to wonder. Given that with-slots and slot-value are couple, why
> haven't I observed analogous couple (with-fields and field-value
> say) for accessors.
Perhaps you are looking for WITH-A
The system that Dan and I are working on does, in fact,
have a 'with-accessors' macro that does just what you think.
On Dec 2, 2010, at 12:37 PM, Ben Hyde wrote:
> On Dec 1, 2010, at 9:51 AM, Daniel Weinreb wrote:
>> The methods called by the callers (1) expect to find the object in a
>> consiste
On Dec 1, 2010, at 9:51 AM, Daniel Weinreb wrote:
> The methods called by the callers (1) expect to find the object in a
> consistent state, and (2) must leave the object in a consistent state
> when they terminate, whether they terminate normally (return) or
> abruptly (signal, return, throw, etc.
You considered the idea that when you write a library (internal
module, whatever) that defines a new type of Lisp object, it should
not necessarily be apparent to the caller whether the implementation
of objects of that type happen to use CLOS.
Hans: Of course, one may want to argue that DEFCL
Sorry for the delay; here are my comments.
Meta-point: I prefer to work out these issues by first disregarding
speed issues, and figuring out what the best semantics is. Then,
later, if there is real need for speedup, we can do that, but keep in
place the original intention of the code, for the
By private email, James Anderson pointed out that accessors are
traceable, whereas SLOT-VALUE is not. To me, that is the most
convincing argument for always using accessors, even in class-internal
initialization code.
Thanks for all your input!
-Hans
On Tue, Nov 16, 2010 at 11:05 AM, Hans Hübne
On 17 November 2010 00:07, Scott L. Burson wrote:
> Presumably the automatically generated methods for the accessor use the
> optimization internally, but the compiler can't inline those methods -- it
Basically yes. (Also, in addition to Andreas' caveat about
implementation differences, note tha
On Tue, Nov 16, 2010 at 13:15, Nikodemus Siivola
wrote:
> Of course, readability and maintainability trump efficiency any time,
> as long as the code if efficient enough for its intended purpose.
I'm not sure that it's entirely right to say slot-value will
definitely be faster. It may be faster i
On Tue, Nov 16, 2010 at 1:15 PM, Nikodemus Siivola <
nikode...@random-state.net> wrote:
> I *think* permutation vectors can be extended to accessors
> as well, but I don't know how commonly that is implemented (eg. SBCL
> at least currently doesn't)
Presumably the automatically generated methods
One angle that hasn't been mentioned yet is efficiency.
There's a fairly well known optimization (permutation vectors) that allows
(defmethod foo ((x bar))
...
(slot-value x 'quux)
...)
to be very efficient as long as X isn't assigned to (and as long as
there is not SLOT-VALUE-USING-CL
On Tue, Nov 16, 2010 at 2:22 AM, Pascal Costanza wrote:
>
> Note that it is always possible to have several accessors with different
> names. So you could define something like this:
>
> (defclass foo ()
> ((some-slot :reader official-slot-reader :accessor
> %internal-slot-accessor) ...))
>
>
I
On 16 Nov 2010, at 11:05, Hans Hübner wrote:
> Hi,
>
> The company I work for has a Common Lisp style guide that generally disallows
> using SLOT-VALUE. Instead, accessor should be used so that: BEFORE and
> :AFTER methods are always invoked when accessing a slot. Generally, I think
> this
Hi,
The company I work for has a Common Lisp style guide that generally
disallows using SLOT-VALUE. Instead, accessor should be used so that:
BEFORE and :AFTER methods are always invoked when accessing a slot.
Generally, I think this is a good idea when looking at classes and instances
from the o
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