[erlang-questions] Programming Erlang: Chap 18, Websockets

[Grzegorz Junka]

On 25/06/2017 21:00, Joe Armstrong wrote:
> Unfortunately cowboy (which I used) and the websockets standard have
> changed since I wrote the book. I also used make and not rebar.
>
> You've now run into what is one of the biggest problems in the
> computer world - code that used to work no longer works despite the
> fact the code itself has not been changed.
>
> One way around this is to use zero dependencies - in fact several
> programs I wrote 30 years ago in Erlang still work fine with no
> changes because there are no external dependencies. (as an aside: this
> is why I like code with zero external dependencies - it takes a lot
> longer to write - but you don't have to support it into the future
> when they things you depend upon change in a manner that is
> incompatible manner)

Joe, I hope you've heard about freezing the code or its dependencies? 
:-) Old applications will still work as long as they run on the same 
version of Erlang and use the same versions of dependencies as the 
example code. But then, even a zere-dependency code isn't guaranteed to 
run on a never version of Erlang as it already had some braking changes 
between releases.

Grzegorz