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Joseph Alotta

mix ins

Greetings,

I want to add a method to the Array class.

#(‘abc’ ‘def’) join => ‘abcdef’

#(‘abc’ ‘def’) join: $/ => ‘abc/def’

I am afraid that if I add it to Array directly, it will get lost in a new update. I want to keep it in my project area.

In ruby, this is called a “mix in”.

How can I do this?

Sincerely,

Joe.

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Bert Freudenberg

Re: mix ins

On Tue, Aug 2, 2016 at 5:03 PM, Joseph Alotta <[hidden email]> wrote:

Greetings,

I want to add a method to the Array class.

#(‘abc’ ‘def’) join => ‘abcdef’

#(‘abc’ ‘def’) join: $/ => ‘abc/def’

I am afraid that if I add it to Array directly, it will get lost in a new update. I want to keep it in my project area.

In ruby, this is called a “mix in”.

How can I do this?

Firstly, these methods exist already. They are defined in SequencableCollection, a superclass of Array, so Array inherits them:

#('abc' 'def') join => 'abcdef'

#('abc' 'def') joinSeparatedBy: '/' => 'abc/def'

Secondly, if you wanted to add these (or other methods), they would not be lost by updating. That is, unless the update specifically includes a method of the same name in the same class. Updating only adds and removes methods, it doesn't "reset" the whole class.

Thirdly, to keep these "extension methods" in your own package, put them in a method category that starts with an asterisk followed by your package name. That is, if your Monticello package is named "Foo-Bar", then put your "mix in" Array methods into the category "*foo-bar" which will mark them as belonging to your package, not the package the Array class is in. The extension methods will be stored and loaded with your package.

Have fun!

- Bert -

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Joseph Alotta

Re: mix ins

> On Aug 2, 2016, at 9:38 AM, Bert Freudenberg [via Smalltalk] <[hidden email]> wrote:
>
> Thirdly, to keep these "extension methods" in your own package, put them in a method category that starts with an asterisk followed by your package name. That is, if your Monticello package is named "Foo-Bar", then put your "mix in" Array methods into the category "*foo-bar" which will mark them as belonging to your package, not the package the Array class is in. The extension methods will be stored and loaded with your package.

Bert,

I am not sure how to do this. My project is called Books. Is this what you mean?

Object subclass: #Array
instanceVariableNames: ''
classVariableNames: ''
poolDictionaries: ''
category: ‘*Books’

Sincerely,

Joe.

PS. Thanks for the bit about the join methods and the changes. :-)

Joseph Alotta

Re: mix ins

In reply to this post by Bert Freudenberg

Bert,

I don’t have these methods. I get an error. See attached:

Sincerely,

Joe.

On Aug 2, 2016, at 9:38 AM, Bert Freudenberg [via Smalltalk] <[hidden email]> wrote:

Firstly, these methods exist already. They are defined in SequencableCollection, a superclass of Array, so Array inherits them:

#('abc' 'def') join => 'abcdef'

#('abc' 'def') joinSeparatedBy: '/' => 'abc/def'

Bert Freudenberg

Re: mix ins

On Tue, Aug 2, 2016 at 5:48 PM, Joseph Alotta <[hidden email]> wrote:

Bert,

I don’t have these methods. I get an error. See attached:

Are you using Squeak 5.0?

- Bert -

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Bert Freudenberg

Re: mix ins

In reply to this post by Joseph Alotta

On Tue, Aug 2, 2016 at 5:39 PM, Joseph Alotta <[hidden email]> wrote:

> On Aug 2, 2016, at 9:38 AM, Bert Freudenberg [via Smalltalk] <[hidden email]> wrote:
>
> Thirdly, to keep these "extension methods" in your own package, put them in a method category that starts with an asterisk followed by your package name. That is, if your Monticello package is named "Foo-Bar", then put your "mix in" Array methods into the category "*foo-bar" which will mark them as belonging to your package, not the package the Array class is in. The extension methods will be stored and loaded with your package.

Bert,

I am not sure how to do this. My project is called Books.

I meant a method category (a.k.a. protocol). Right-click in Array's method categories list and add a new category named *books. Then select it and put your methods there. You can also use drag-and-drop to move a method to the right category.

- Bert -

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Joseph Alotta

Re: mix ins

In reply to this post by Bert Freudenberg

4.3

What is the procedure for upgrading? Should I file-out the classes, download the new version and then file-in?

Sincerely,

Joe.

> On Aug 2, 2016, at 1:31 PM, Bert Freudenberg [via Smalltalk] <[hidden email]> wrote:
>
> On Tue, Aug 2, 2016 at 5:48 PM, Joseph Alotta <[hidden email]> wrote:
> Bert,
>
> I don’t have these methods. I get an error. See attached:
>
>
> Are you using Squeak 5.0?
>
> - Bert -
>
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> http://lists.squeakfoundation.org/mailman/listinfo/beginners
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Bert Freudenberg

Re: mix ins

On Tue, Aug 2, 2016 at 8:55 PM, Joseph Alotta <[hidden email]> wrote:

4.3

What is the procedure for upgrading? Should I file-out the classes, download the new version and then file-in?

That would be one simple way to do it, yes.

OTOH if you're happy with 4.3 there is no need to upgrade - just add the methods you need to your image.

- Bert -

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Joseph Alotta

Re: mix ins

Hi Bert,

I downloaded Squeak 5.0. Seems to work well. But I have a few issues:

1. How do I make the system font bigger?

2. How do I make the flaps disappear?

Sincerely,

Joe.

Joseph Alotta

Re: mix ins

In reply to this post by Bert Freudenberg

I was able to get everything working fine on 5.0. I like it better than 4.3. I think you guys have done a great job!!

Thank you.

Joe.

> On Aug 2, 2016, at 8:07 PM, Joseph Alotta <[hidden email]> wrote:
>
> Hi Bert,
>
> I downloaded Squeak 5.0. Seems to work well. But I have a few issues:
>
> 1. How do I make the system font bigger?
>
> 2. How do I make the flaps disappear?
>
> Sincerely,
>
> Joe.
>
>
>