Smalltalk › Squeak › Squeak - Beginners

Object clone

_‹ Previous Topic Next Topic _›

Classic

List

Threaded

9 messages Options

Jakub-8

Object clone

hello,

i want do i want set var a as all instance vars of b. Something s clone - coppy of one object. I look for clone command in SBE book but i found nothing.

Thnx.

--
Jakub.
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Ralph Johnson

Re: Object clone

On Jan 14, 2008 3:42 PM, Jakub <[hidden email]> wrote:
> I look for clone command in SBE book but i found
> nothing.

Perhaps you are looking for the #copy method. Also, see #shallowCopy
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Mathieu SUEN

Re: Object clone

In reply to this post by Jakub-8

Hi Jakub

I don't really understand your question.
What is a and b? Are they instance of the same class?

On Jan 14, 2008, at 10:42 PM, Jakub wrote:

> hello,
>
> i want do i want set var a as all instance vars of b. Something s
> clone - coppy of one object. I look for clone command in SBE book
> but i found nothing.
>
> Thnx.
>
> --
> Jakub. _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners

Mth

_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Jakub-8

Re: Object clone

yeah a, b instance of same class and i want copy all instance variables values to a i want do a := b but i dont want to a is same object as b. In memory will be two objects a, b with same values .. but if i change a i dont change b.

regards

2008/1/15, Mathieu Suen <[hidden email]>:

Hi Jakub

I don't really understand your question.
What is a and b? Are they instance of the same class?

On Jan 14, 2008, at 10:42 PM, Jakub wrote:

> hello,
>
> i want do i want set var a as all instance vars of b. Something s
> clone - coppy of one object. I look for clone command in SBE book
> but i found nothing.
>
> Thnx.
>
> --
> Jakub. _______________________________________________
> Beginners mailing list
> [hidden email]
> http://lists.squeakfoundation.org/mailman/listinfo/beginners

Mth

_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

--
Jakub.
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Randal L. Schwartz

Re: Object clone

>>>>> "Jakub" == Jakub <[hidden email]> writes:

Jakub> yeah a, b instance of same class and i want copy all instance variables
Jakub> values to a i want do a := b but i dont want to a is same object as b. In
Jakub> memory will be two objects a, b with same values .. but if i change a i dont
Jakub> change b.

b := a copy.

but you might also want to look at #deepCopy.

--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<[hidden email]> <URL:http://www.stonehenge.com/merlyn/>
Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Marcin Tustin

Re: Object clone

So, I take it that clone is a "stupider" (no postCopy polymorphism) version of copy (or shallowCopy). Is that right, or does it do something odd?

On Jan 15, 2008 5:38 PM, Randal L. Schwartz < [hidden email]> wrote:

>>>>> "Jakub" == Jakub < [hidden email]> writes:

Jakub> yeah a, b instance of same class and i want copy all instance variables
Jakub> values to a i want do a := b but i dont want to a is same object as b. In
Jakub> memory will be two objects a, b with same values .. but if i change a i dont
Jakub> change b.

b := a copy.

but you might also want to look at #deepCopy.

--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<[hidden email]> <URL:http://www.stonehenge.com/merlyn/ >
Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Randal L. Schwartz

Re: Object clone

>>>>> "Marcin" == Marcin Tustin <[hidden email]> writes:

Marcin> So, I take it that clone is a "stupider" (no postCopy polymorphism) version
Marcin> of copy (or shallowCopy). Is that right, or does it do something odd?

Object>>#clone looks like an optional-implemented primitive that
does a #shallowCopy, but without the fallback-to-smalltalk that #shallowCopy
performs. Not sure why those are both in the image.

I'd stick with #copy unless I was the implementor of the class being
copied, and even then, I'd make copy "do the right thing". :)

--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<[hidden email]> <URL:http://www.stonehenge.com/merlyn/>
Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Klaus D. Witzel

Object copyFrom: [was: Object clone]

In reply to this post by Jakub-8

Hi Jakub,

on Tue, 15 Jan 2008 18:29:53 +0100, you wrote:

> yeah a, b instance of same class and i want copy all instance variables
> values to a i want do a := b but i dont want to a is same object as b. In
> memory will be two objects a, b with same values ..

If you mean to have class Person and (aPerson := Person new), (bPerson :=
Person new) and later you want that aPerson has exactly the same instance
variables as bPerson, then you might want

aPerson copyFrom: bPerson

This is not often used (it's rather at the system level), because most
Smalltalk developers set instance variables by mutators, like

aPerson name: bPerson name.
aPerson address: bPerson address.
...

See also the comment in #copyFrom: on the instance side of Object.

Enjoy Smalltalk :)

/Klaus

> but if i change a i dont
> change b.
>
> regards
>
> 2008/1/15, Mathieu Suen <[hidden email]>:
>>
>> Hi Jakub
>>
>> I don't really understand your question.
>> What is a and b? Are they instance of the same class?
>>
>> On Jan 14, 2008, at 10:42 PM, Jakub wrote:
>>
>> > hello,
>> >
>> > i want do i want set var a as all instance vars of b. Something s
>> > clone - coppy of one object. I look for clone command in SBE book
>> > but i found nothing.
>> >
>> > Thnx.
>> >
>> > --
>> > Jakub. _______________________________________________
>> > Beginners mailing list
>> > [hidden email]
>> > http://lists.squeakfoundation.org/mailman/listinfo/beginners
>>
>> Mth
>>
>>
>>
>> _______________________________________________
>> Beginners mailing list
>> [hidden email]
>> http://lists.squeakfoundation.org/mailman/listinfo/beginners
>>
>
>
>

_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

Xinyu Liu

Re: Object clone

In reply to this post by Randal L. Schwartz

Hi,

In squeak copy is implemented as:
^self shallowCopy postCopy

and deepCopy just copy 2 layers of instance, so if the object has tree like sub instance, postCopy must be implemented.

Best regards.
-Liu Xinyu

On Jan 16, 2008 2:11 AM, Randal L. Schwartz <[hidden email]> wrote:

>>>>> "Marcin" == Marcin Tustin <[hidden email]> writes:

Marcin> So, I take it that clone is a "stupider" (no postCopy polymorphism) version
Marcin> of copy (or shallowCopy). Is that right, or does it do something odd?

Object>>#clone looks like an optional-implemented primitive that
does a #shallowCopy, but without the fallback-to-smalltalk that #shallowCopy
performs. Not sure why those are both in the image.

I'd stick with #copy unless I was the implementor of the class being
copied, and even then, I'd make copy "do the right thing". :)

--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<[hidden email]> <URL: http://www.stonehenge.com/merlyn/>
Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners

_______________________________________________
Beginners mailing list
[hidden email]
http://lists.squeakfoundation.org/mailman/listinfo/beginners