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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 10:39:52 +0100
> On 02/08/2011 09:58 AM, Stefan Sobernig wrote:
>> 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).
>>
>
> Thank you for this example. I forgot to mention that my application
> will, in some cases, create argument list that may be long (few thousand
> integer values). I expect it to handle up to 7200 values that are
> integers (2 digits maximum).
This changes the picture. If you look at my examples, they assume that
you want to turn each list value a value to a proper method parameter
and so into a local variable in the init body ($a, $b, $c, ...). This is
certainly not the case here ...
What is going to happen to with this data vector in init? Why do you
want to treat each value of this vector as a method parameter of init?
> Is it a bad idea to expand that list and
> pass 7200 arguments to init?
Let me rephrase the question: Is it a bad idea to have a method with
7200 method parameters :) Besides: The # of method parameter of init
would have to change which each call, depending on the size of your data
vector.
One might think of using args on init, but args simply boxes a variable
argument vector into a single Tcl list. So why not pass the data vector
as a single list value right from the beginning?
> In this example it appears that it is actually better to expend the list
> using {*}, than to pass it as a value?
Only and only *iff* you want to treat each list value as a method
parameter. In your scenario, it is more likey a data vector which is to
be addressed by a single handle:
MyClass instproc init {v} {
foreach value $v {
# do sth. to each of the 7200 values
}
}
//stefan
Date: Tue, 08 Feb 2011 10:39:52 +0100
> On 02/08/2011 09:58 AM, Stefan Sobernig wrote:
>> 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).
>>
>
> Thank you for this example. I forgot to mention that my application
> will, in some cases, create argument list that may be long (few thousand
> integer values). I expect it to handle up to 7200 values that are
> integers (2 digits maximum).
This changes the picture. If you look at my examples, they assume that
you want to turn each list value a value to a proper method parameter
and so into a local variable in the init body ($a, $b, $c, ...). This is
certainly not the case here ...
What is going to happen to with this data vector in init? Why do you
want to treat each value of this vector as a method parameter of init?
> Is it a bad idea to expand that list and
> pass 7200 arguments to init?
Let me rephrase the question: Is it a bad idea to have a method with
7200 method parameters :) Besides: The # of method parameter of init
would have to change which each call, depending on the size of your data
vector.
One might think of using args on init, but args simply boxes a variable
argument vector into a single Tcl list. So why not pass the data vector
as a single list value right from the beginning?
> In this example it appears that it is actually better to expend the list
> using {*}, than to pass it as a value?
Only and only *iff* you want to treat each list value as a method
parameter. In your scenario, it is more likey a data vector which is to
be addressed by a single handle:
MyClass instproc init {v} {
foreach value $v {
# do sth. to each of the 7200 values
}
}
//stefan