Minimal websocket chat with goroutines and channels

Two posts in one day. In previous post I showed the first version of goroutines and channels in Rye. Now I joined them with websockets into a minimal chat example.

All Go chat examples were quite complex so I couldn't use them and I pretty much tried the simplest structure of channels, sockets, goroutines that made sense to me. And it worked. This could mean that Go channels are pretty intuitive and flexible tool.

The code works with restarts and disconnects. Rye's failure management with purge (inverse of HOF filter) worked quite nicely for cleaning up the closed sockets.

Now that all this message passing works, I would only need to add additional structure to messages, sockets and the hub. To add nicknames, enter - leave events, history, etc ...

Maybe I will discover I am using sockets wrong here as I better get to know Go's concurrency. Although it works I am not 100% sure if I can read and write to a websocket from two different goroutines. Maybe some syncing mechanism will be needed?

New standard functions

For this to work I also needed to add some standard functions. I created purge, switch, failed? and eval.

Eval is a very common Rebol function but there it is called reduce. When rebol was created map/reduce wasn't yet popular, now eval makes more sense I think. Eval in Javascript and Python evaluates the code, like do in Rebol and Rye does. Reduce evaluates a block of expresions into a block of values, so it sounds appropriate. Since this is one of most used words in Rye/Rebol the shorter eval vs evaluate makes sense.

Komentarji

Priljubljene objave iz tega spletnega dnevnika

Less variables, more flows example vs Python

In the last blogpost ( Less variables, more flows ) I wrote a quick practical script I needed. It was an uncommon combination of CGI, two GET requests with Cookies and a POST request with Authorization header. I really like practical random/dirty problems, rather than ideal - made up problems to test the language. To get a sense of comparison I rewrote the example 2 times while removing specific Rye features. But that comparison is meaningless to a person that doesn't know Rye or at least Rebol already. So I went on fiverr and made a request for a Python script with these requirements. I got a nicely written Python script that uses functions for each step. To be more comparable, I rewrote the Rye code to a similar structure. Below is the result ... For a next step, it would be interesting, to extract a little simpler example out and add error handling. With Rye-s specific failure handling, I think the difference would become even greater. You can find Rye on github .

Preberite več

Ryelang - controlled file serving example and comparison to Python

This is as anecdotal as it gets, but basic HTTP serving functions in Rye seem to be working quite OK. They do directly use the extremely solid Go 's HTTP functions, so that should be somewhat expected. I made a ryelang.org web-server with few lines of Rye code 3 months ago and the process was running ever since and served more than 30.000 pages. If not else, it seems there are no inherent memory leaks in Rye interpreter. Those would probably show up in a 3 month long running process? And now I got another simple project. I needed to make a HTTP API for some mobile app. API should accept a key, and return / download a binary file in response if the key is correct. Otherwise it should return a HTTP error. So I strapped in and created Rye code below. I think I only needed to add generic methods stat and size? , all other were already implemented, which is a good sign. Of course, we are in an age of ChatGPT, so I used it to generate the equivalent Python code. It used the elegant

Preberite več

Receiving emails with Go's smtpd and Rye

This goes a while back. At some project for user support, we needed to receive emails and save them to appropriate databases. The best option back in the day seemed project Lamson . And it worked well ever since. It was written in Python by then quite known programmer Zed Shaw. It worked like a Python based SMTP server, that called your handlers when emails arrived. It was sort of Ruby on Rails for email. We were using this ever since. Now our system needs to be improved, there are still some emails or attachments that don't get parsed correctly. That isn't the problem of Lamson, but of our code that parses the emails. But Lamson development has been passive for more than 10 years. And I am already moving smaller utilities to Rye. Rye uses Go, and Go has this nice library smtpd , which seems like made for this task. I integrated it and parsemail into Rye and tested it in the Rye console first. Interesting function here is enter-console , that can put you into Rye console any

Preberite več

ryelang

Preišči ta spletni dnevnik