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Re: [Xotcl] Expand init arguments and custom destructor
From: Stefan Sobernig <stefan.sobernig_at_wu.ac.at>
Date: Tue, 08 Feb 2011 09:58:03 +0100
Krzysztof,
> 1. Is it less efficient if I expand a list before providing it as an
> argument for init?
>
> set myList [list 1 2 3 4]
>
> MyClass myObject $myList
>
> vs
>
> eval MyClass myObject $myList
well, it depends on what you want to achieve. Is it just about boxing
the arguments in a list and then, for further processing unboxing it
(e.g., in the init body?). Or are the values treated as a list in
follow-up steps?
the script below sheds some light on various scenarios (you can run it
to reproduce on your machine; timing in microsecs per iteration, 10000
iterations each):
t.001: 26.2 mms, MyClass myObject $myList; set ::out
t.002: 32.6 mms, eval MyClass myObject $myList; set ::out
t.003: 26.9 mms, MyClass myObject 1 2 3 4; set ::out
t.004: 26.0 mms, MyClass myObject {*}$myList; set ::out
from this bird eye perspective (and without knowing the details of your
scenario), you might want to consider avoiding the [eval] overhead by
using the {*} operator in 8.5+ for the boxing case ...
(t.003 is a kind of baseline measurement and appears slightly more
expensive because the values in the argument vector must be turned into
Tcl_Objs first etc., a conversion which has already been achieved if
dealing with a [list] and its values).
> 2. When do I need to create a custom destructor? I create objects inside
> init - do I have to do that in this case, or will those object be
> destroyed automatically when I destroy their parent?
>
> MyClass instproc init args {
>
> my contains {
> MySecondClass innerObject
> }
> }
The deletion of parents cascades. So there is no need for a custom
destructor on a parent to deal with its kids.
//stefan
>
> Best Regards,
> Krzysztof
>
>
>
> _______________________________________________
> Xotcl mailing list
> Xotcl_at_alice.wu-wien.ac.at
> http://alice.wu-wien.ac.at/mailman/listinfo/xotcl
Date: Tue, 08 Feb 2011 09:58:03 +0100
Krzysztof,
> 1. Is it less efficient if I expand a list before providing it as an
> argument for init?
>
> set myList [list 1 2 3 4]
>
> MyClass myObject $myList
>
> vs
>
> eval MyClass myObject $myList
well, it depends on what you want to achieve. Is it just about boxing
the arguments in a list and then, for further processing unboxing it
(e.g., in the init body?). Or are the values treated as a list in
follow-up steps?
the script below sheds some light on various scenarios (you can run it
to reproduce on your machine; timing in microsecs per iteration, 10000
iterations each):
t.001: 26.2 mms, MyClass myObject $myList; set ::out
t.002: 32.6 mms, eval MyClass myObject $myList; set ::out
t.003: 26.9 mms, MyClass myObject 1 2 3 4; set ::out
t.004: 26.0 mms, MyClass myObject {*}$myList; set ::out
from this bird eye perspective (and without knowing the details of your
scenario), you might want to consider avoiding the [eval] overhead by
using the {*} operator in 8.5+ for the boxing case ...
(t.003 is a kind of baseline measurement and appears slightly more
expensive because the values in the argument vector must be turned into
Tcl_Objs first etc., a conversion which has already been achieved if
dealing with a [list] and its values).
> 2. When do I need to create a custom destructor? I create objects inside
> init - do I have to do that in this case, or will those object be
> destroyed automatically when I destroy their parent?
>
> MyClass instproc init args {
>
> my contains {
> MySecondClass innerObject
> }
> }
The deletion of parents cascades. So there is no need for a custom
destructor on a parent to deal with its kids.
//stefan
>
> Best Regards,
> Krzysztof
>
>
>
> _______________________________________________
> Xotcl mailing list
> Xotcl_at_alice.wu-wien.ac.at
> http://alice.wu-wien.ac.at/mailman/listinfo/xotcl
-- Institute for Information Systems and New Media Vienna University of Economics and Business Augasse 2-6, A-1090 Vienna `- http://nm.wu.ac.at/en/sobernig `- stefan.sobernig_at_wu.ac.at `- ss_at_thinkersfoot.net `- +43-1-31336-4878 [phone] `- +43-1-31336-746 [fax]