I'm the one to blame for adding traits in the FS-AnsiStreams package. At least in my "fork" for Squot and now Tonel that resides on GitHub. I tried to have the readable stream, positionable stream, and writable stream protocols like in the ANSI standard and experimented with that. Might not be the most efficient way, but it works and avoids some the duplication from the traditional Stream class hierarchy.

In Pharo they abandoned the "new" ansi streams and integrated StandardFileStream & co. in FS instead.

Levente Uzonyi <leves@caesar.elte.hu> schrieb am So., 31. März 2019, 21:21:

On Sat, 30 Mar 2019, David T. Lewis wrote:

> Changing the subject line to focus on Levente's question.
>
> On Thu, Mar 28, 2019 at 06:43:11PM +0100, Levente Uzonyi wrote:
>>
>> What are the current use cases for traits?
>
> In order to experiment with Git based repositories, I have loaded the
> Tonel package from the github repositories of Jakob Reschke.
>
> Installer ensureRecentMetacello.
> (Smalltalk classNamed: #Metacello) new
> repository: 'github://j4yk/tonel:squeak';
> baseline: 'Tonel';
> load.
>
> This brings in the FS-AnsiStreams package, which uses traits.
>
> Having traits in Squeak allows me to load this package.

I haven't tried your snippet and I don't know which version of FS depends
on Traits, but the one on SqueakSource definitely does not.
Btw, Traits can be flattened, so it's possible to make it loadable into
images with no Trait support.

So far all use cases of Traits in this thread (and its parent) were about
interfaces. Squeak doesn't have a concept for that, and Traits are
definitely more than just simple interfaces (as long as you don't want to
interface state). Perhaps we need interfaces instead of traits.

Levente

>
> Dave