21 ms·

Erlang/OTP 20.0

391 points by okket 9y ago

desireco42 9y ago
This is probably better page to look, as I don't actively look at Erlang, but as Elixir developer I am very interested in it. http://www.erlang.org/news/114 http://www.erlang.org/news/114
- sushisource 9y ago
  Nice: When a gen_server crashes, the stacktrace for the client will be printed to facilitate debugging.
- sotojuan 9y ago
  If you're an Elixir dev, it pays to both keep an eye on Erlang and learn its standard library (the parts not implemented in Elixir). There's a lot stuff already in there that you don't have to reinvent when doing Elixir. And of course, every OTP release directly affects Elixir.
- cmpaul 9y ago
  Looking for work? :) https://jobs.lever.co/hellosign/39ea6c41-8ff8-4c93-b0fd-4a6224ef29ec https://jobs.lever.co/hellosign/39ea6c41-8ff8-4c93-b0fd-4a62...
  - desireco42 9y ago
    Yes :) I am in Chicago, I would be happy to do remote work.
    - Arcsech 9y ago
      I just want to echo this: I work in Elixir on side projects at least, and HelloSign sounds like a cool place to work! But no way I'm moving to California.
rdtsc 9y ago
Some things I like from the new release: * Dirty schedulers: This allows easy integration of blocking C-based libraries. So for example can wrap something like RocksDb and make it available to the rest of the VM easier. Or libcurl and others. * DTLS : This lets it talk to WebRTC clients * Erlang literals are no longer copied when sending messages : This is kinda of a sneaky one. By default (with exception of large binaries) Erlang VM usually copies data when it sends messages. However, in this case module literals (constants, strings, etc) will be another thing that's not copied. There is a hack to dynamically compile configuration values or other tables of constants as a module at runtime. So if you use that hack, you'd get a nice performance boost. * code_change, terminate and handle_info callbacks optional in the OTP behaviors. This is very nice. I always wondered why I had to write all that boiler plate code. Also here is a detailed list of changes: http://erlang.org/download/otp_src_20.0-rc2.readme http://erlang.org/download/otp_src_20.0-rc2.readme
- fredliu 9y ago
  * DTLS : This lets it talk to WebRTC clients Could you elaborate more on this? I don't know much about erlang/OTP's support for WebRTC. Does adding DTLS makes erlang/OTP possible to talk to WebRTC clients because WebRTC requires DTLS? or this means erlang/OTP now has a complete stack and API for WebRTC communication out of the box?
  - rdtsc 9y ago
    DTLS is TLS (SSL) but for datagrams (UDP) instead of the traditional streams (TCP). WebRTC uses DTLS as one of its base protocols. The other one is SRTP but even its setup requires DTLS. I am not sure how complete the rest of the support it but having DTLS is a major step ahead.
    - fredliu 9y ago
      Thanks for the clarification. I was aware of the DTLS requirement for WebRTC, but not sure the whole WebRTC stack support on erlang/OTP. Now thinking about it, maybe an erlang/elixir/whatever-on-BEAM implementation of STUN/TURN server would make sense...
brian_herman 9y ago
Is there like a why's poignant guide to ruby for erlang?http://poignant.guide/book/ http://poignant.guide/book/
- shadeless 9y ago
  There's "Learn You Some Erlang for great good!" (http://learnyousomeerlang.com/ http://learnyousomeerlang.com/), which is a great (the best?) resource for learning Erlang.
  - hordeallergy 9y ago
    I found it too densely informative. After the 2nd or 3rd attempt I ditched it and just jumped into programming. Personal preference possibly. I think erlang's difficulty is exaggerated. Just jump in - the immediate little wins will lubricate the process.
    - derefr 9y ago
      "Densely informative" is the right way for a textbook to be, I think. You're not meant to read LYSE or books like it straight through; rather, each individual paragraph is dense enough with facts that after every one, you should stop and tinker with a toy example or two at the REPL to collect your thoughts and make sure you understand what's going on. If you imagine someone teaching Erlang with LYSE serving as the actual textbook, they'd do what is done with most textbooks: split each chapter into rather small segments, and have you do exercises after each one to "interactively" absorb the knowledge.
- jmcgough 9y ago
  As a rubyist, I found Elixir was a great entrypoint - from there you can learn OTP behaviors like GenServer, and slowly start to learn Erlang syntax from using stuff like its data structures or ETS. Haven't found anything as great as why's guide yet though. Maybe it's just waiting to be written by someone :)
- marianoguerra 9y ago
Medaber 9y ago
A better link would be the "What's New" page. https://www.erlang.org/news/112 https://www.erlang.org/news/112
atemerev 9y ago
Erlang is awesome. The only problem preventing me to use it where I want to is terrible file I/O performance, especially on writes. I tried to Google the solution, but it seems that there isn't anything generally accepted for the moment.
- marianoguerra 9y ago
  something specific? did you tried raw file handles? http://erlang.org/doc/man/file.html#open-2 http://erlang.org/doc/man/file.html#open-2
  - atemerev 9y ago
    Yes, and delayed_write as well. I tried to port a (very simplistic, but fast) market data append-only database from Scala to Erlang. In Scala, I have no performance issues, but the code is unnecesarily complex to my taste. In Scala, I am getting around 100000 events per second, with great additional optimization margins (memory mapped files are great). In Erlang, it barely works with few hundred events per second. Right now I have googled that disk_log in Erlang is fast enough, but it uses Erlang's own internal binary format (there is an option to plug custom codecs, but it is wonderfully under-documented, to say the least). This looks strange to me, because Erlang is well-optimized regarding the network IO. What's the difference for file IO?
    - derefr 9y ago
      > Erlang is well-optimized regarding the network IO. What's the difference for file IO? IIRC, async network IO is handled by the VM's scheduler threads each just calling a non-blocking select() on the fdset of sockets it holds port()s for every once in a while. This is because TCP/IP implementations are pretty much guaranteed to expose a non-blocking select() for sockets, and do in every OS Erlang is written for. Disk IO, on the other hand, is done by throwing the calls over to special async IO threads, which have to send responses back to the scheduler that wants them using (I think zero-copy) IPC. This is done because not all OSes have the equivalent of non-blocking select() for file handles (i.e. what you get from using fcntl(2) + read(2) in Linux.) So Erlang's disk IO BIFs fundamentally require context-switches and/or NUMA messaging. You get to avoid this if you use your own NIFs—which have the lovely property of running in the calling scheduler by default, with the ability to decide on each call whether the workload for this particular call is small enough to perform synchronously, or whether it should be scheduled over to a dirty scheduler, blocking the Erlang process and yielding the scheduler. In other words, this is like the disk IO BIFs in the worst case, and can be a lot faster in the best case. It's a lot like NT's "overlapped IO" primitives, actually. You could also use higher-level BIFs. There is a reason Mnesia is implemented in terms of special BIFs (DETS) rather than DETS being a functional layer implemented using the disk IO BIFs. Mind you, DETS probably doesn't have the API you're looking for, but there are a number of NIF libraries that plug low-level "storage engines" into Erlang as NIFs that provide equivalent convenience: • https://github.com/cloudant/nifile https://github.com/cloudant/nifile • https://github.com/basho/eleveldb https://github.com/basho/eleveldb • https://github.com/gburd/lmdb https://github.com/gburd/lmdb And there's also always the option to do what Erlang-on-Xen does: forego anything that "devolves into" disk IO entirely, implementing the file module in terms of network IO—the p9 protocol in their case. This is actually likely the lowest-overhead move you can make if you're going to be running your Erlang node on a VM that would just be talking to a virtual disk mounted from a SAN anyway. Instead of the OS mounting the disk from the SAN and Erlang talking to the OS, you can just have Erlang talk to the SAN directly using e.g. iSCSI.
marianoguerra 9y ago
Also the docs got a facelift: http://erlang.org/doc/ http://erlang.org/doc/ Now that we are talking Erlang: What's missing in Erlang that would be valuable to you? What are the biggest pain points right now on the Erlang ecosystem that makes it harder for you to try it/adopt it?
- marianoguerra 9y ago
  didn't noticed that the submitted link is to the docs :P
- StreamBright 9y ago
  For me the biggest pain point was the lack of great libraries for doing basic stuff like HTTP requests (client side). I was not able to reach the performance of Java/JVM with the Erlang implementation and I could not figure out what I am doing wrong. OTP and those pattern associated with it are still a bit opaque after reading countless manuals, howtos and books.
- deleted 9y ago
  [deleted]
- derefr 9y ago
  > Also the docs got a facelift You can finally zoom into them on mobile without the sidebar covering half the text :D
  - pmontra 9y ago
    They forgot to fix it for Firefox. I guess they're using only Chrome.
- digitalzombie 9y ago
  > What are the biggest pain points right now on the Erlang ecosystem that makes it harder for you to try it/adopt it? Personally, Erlang solve stuff that is very niche and I don't have any project in those stuff. Elixir web frameworks really help in term of practicing the language. Erlang had cowboy, etc.. but it wasn't close to the other MVC language. So practicing Erlang to get real experiences in it was hard. Maybe there should be a page of examples of other problem Erlang can solve so I can decide which problem I like to start a project on? Cause so far when I think of Erlang it's just concurrency, back end protocol, etc... But I'm sure there may be other problems it can be address that I don't know about and that I would like to start a trivial project on it.
sho 9y ago
My favourite feature - shell history finally in core! That's been a possibly irrational but personally annoying omission for years, and required messy hacks to get around - not a good beginner experience for what I consider to be pretty basic functionality. It's enabled by an envar as described by the hero who cleaned up the hack and ported it here: https://github.com/ferd/erlang-history https://github.com/ferd/erlang-history
- marianoguerra 9y ago
  yes, that's a great addition. for the lazy: Add `export ERL_AFLAGS="-kernel shell_history enabled"` to your profile and get shell history out of the box with #Erlang/OTP 20 (from https://twitter.com/mononcqc/status/877544929496629248 https://twitter.com/mononcqc/status/877544929496629248)
- mononcqc 9y ago
  Bit of history on the feature. The hack was an old thing I had written at a hackathon over half a decade ago. It had little cost to regulars who had installed it at least once before. It relied on DETS and had transient issues with corruption of history files, but nothing major enough for anyone to take notice or get mad about it. I myself ended up working on other projects once that one was good enough (including the search function with ctrl+r in the shell -- that wasn't there at first, and then things like rebar3 and other side projects), and nobody really ever took over or reimplemented a better shell history around it, nor took the time to port it to OTP. I had also asked for help in the past for a better implementation that didn't rely on DETS, but not a lot of people were interested or knew how to proceed any better than I did. Eventually I just got tired and reimplemented it with the disk_log module and some log fragmentation and rotation to avoid dropping the whole file every time a limit was reached. It took a few weeks of review to get it in and so far nobody has complained about it. I think the overall lesson is that the moment you have a quick hack to do the job, regulars get used to them, but forget about the beginner's experience where what you have to do is apply all the hacks at once and dear lord does it ever look janky then.
  - im_down_w_otp 9y ago
marianoguerra 9y ago
if you want to get started but don't know where this is a good place to start: http://spawnedshelter.com/ http://spawnedshelter.com/ there's a online course by Simon Thompson from the University of Kent that started 2 days ago, you may be able to join: https://www.futurelearn.com/courses/functional-programming-erlang https://www.futurelearn.com/courses/functional-programming-e... if you like the ideas but want to try something different there are alternative languages that run on the Erlang VM: * Elixir with a ruby-like syntax: https://elixir-lang.org/ https://elixir-lang.org/ * LFE (Lisp Flavoured Erlang): http://lfe.io/ http://lfe.io/ * Efene with a python-like syntax: http://efene.org/ http://efene.org/ and one in development but already looking really interesting: Alpaca, an ML inspired language: https://github.com/alpaca-lang/alpaca https://github.com/alpaca-lang/alpaca
- dbcurtis 9y ago
  Thanks! I came here to ask the "How do I Erlang?" question. Erlang has been on my radar for a long time but I've never taken the time to dig in. 85% of my code output is obscure protocol stacks in Python+Twisted, the other 15% is real-time embedded C over an RTOS. Even if I can't use Erlang in production, I'm sure I'd find food for thought in the concepts.
  - digitalzombie 9y ago
    http://learnyousomeerlang.com/ http://learnyousomeerlang.com/ That book is a good place to start. > Even if I can't use Erlang in production, I'm sure I'd find food for thought in the concepts. Oh boy are you going to be in for a treat. The concept for no loop construct other than recursion and recursive thinking was worth it for the little time I dabble in Erlang.
    - equalunique 9y ago
      As an erlang newcomer, the non-loop seems to be one of the most intriguing concepts, IMO.
      - 9y ago
thedaemon 9y ago
Just an FYI Wings3D http://www.wings3d.com/ http://www.wings3d.com/ is built with Erlang. It is a Symbolics style 3d Modelling application using the Winged Edge data structure.
2017throw 9y ago
My favourite DSL!
chx 9y ago
Let's note that Elixir is already compatible with it. Phoenix/Elixir, I feel, is the future of web apps.
- pmontra 9y ago
  I used to think the same but I'm not sure about it now. We have plenty of managed backends now and they usually support Node, Python and a few other languages [1]. BEAM ones are never among them. Furthermore the deployment story now is all about docker, which is at odds with the mosts advanced features of BEAM (hot reload, but I guess few people use it.) So, it might be the future for fully self managed web apps, but developers are moving in another direction now. That damages the mindshare. [1] Basically the owners of those backends have a voice in which languages succeed and which not. They'll never support more than a handful of languages, because of the maintenance costs.
lokedhs 9y ago
I have tried on multiple occasions to learn and use Erlang for some different projects. My process has always been stopped by a few specific things, and I end up going back to Common Lisp, which tends to be much easier to get to work. My first problem is to make sense out of how to actually run a server application. Manually compiling source files and run functions is one thing, but trying to actually set up an application with all the monitors and stuff is really annoyingly hard. Even following step-by-step instructions resulted in errors that I didn't understand as soon as I tried to do anything outside what the tutorial showed. The second issue that I have never managed to properly solve is how to use libraries. In particular, I have wanted to use the client libraries for RabbitMQ and CouchDB (both written in Erlang, so you'd expect it to be simple). The instructions how to install the libraries usually doesn't match the thing you actually download. I've also tried to use the EDTS in Emacs, which is pretty nice, but as soon as I try to use a library, it can never find the hrl files. I really want to use Erlang, but the difficulty of actually getting started with a real project as opposed to simple tutorial stuff has been extremely frustrating.
- JamesUtah07 9y ago
  Try out elixir. It runs on the Erlang VM but is easy to get up and running and has a great community. It's much easier to add external libraries and uses its own package manager.
  - lokedhs 9y ago
    Thanks for the suggestions (you, and the other two people mentioning the same thing). I have just started looking at Elixir, and I'm hoping that will work better. Am I just to assume that Erlang deployment really is as complicated and poorly documented as I thought, since no one suggested any documentation, but three people suggested I switch to Elixir.
    - klibertp 9y ago
      In my experience, Erlang doesn't have a standard way of doing a deployment. There are 3rd party apps like Rebar and others, but they are both not available by default (after a fresh install) and seriously underdocumented. The result of this, IMHO, is that everyone builds their own build and deployment system, using shell scripting, Make or Erlang itself. Elixir includes Mix - a standard task runner - and Hex as part of the distribution. It also provides a central pkg repository (https://hex.pm/packages https://hex.pm/packages). It's much, much easier to start a project and pull all your dependencies. I guess you could use Hex and Mix with pure Erlang projects, but I haven't tried this.
wtian2000 9y ago
Somewhat irrelevant, but I noticed that the copyright line at the bottom still says "Copyright © 1999-2016 Ericsson AB". Should it be updated to 2017?
di4na 9y ago
Something that most people seems to have missed > The non SMP Erlang VM is deprecated and not built by default In 2017, most languages are still fighting to get a multicore implementation. Erlang is ditching their single core one.
lngnmn 9y ago
It seems that the source build is broken. At least a straightforward attempt to build otp from github sources with latest clang/lld has been failed.

391 points by okket 9y ago

This is probably better page to look, as I don't actively look at Erlang, but as Elixir developer I am very interested in it. http://www.erlang.org/news/114 http://www.erlang.org/news/114

sushisource 9y ago
Nice: When a gen_server crashes, the stacktrace for the client will be printed to facilitate debugging.
sotojuan 9y ago
If you're an Elixir dev, it pays to both keep an eye on Erlang and learn its standard library (the parts not implemented in Elixir). There's a lot stuff already in there that you don't have to reinvent when doing Elixir. And of course, every OTP release directly affects Elixir.
cmpaul 9y ago
Looking for work? :) https://jobs.lever.co/hellosign/39ea6c41-8ff8-4c93-b0fd-4a6224ef29ec https://jobs.lever.co/hellosign/39ea6c41-8ff8-4c93-b0fd-4a62...
- desireco42 9y ago
  Yes :) I am in Chicago, I would be happy to do remote work.
  - Arcsech 9y ago
    I just want to echo this: I work in Elixir on side projects at least, and HelloSign sounds like a cool place to work! But no way I'm moving to California.

rdtsc 9y ago

Some things I like from the new release: * Dirty schedulers: This allows easy integration of blocking C-based libraries. So for example can wrap something like RocksDb and make it available to the rest of the VM easier. Or libcurl and others. * DTLS : This lets it talk to WebRTC clients * Erlang literals are no longer copied when sending messages : This is kinda of a sneaky one. By default (with exception of large binaries) Erlang VM usually copies data when it sends messages. However, in this case module literals (constants, strings, etc) will be another thing that's not copied. There is a hack to dynamically compile configuration values or other tables of constants as a module at runtime. So if you use that hack, you'd get a nice performance boost. * code_change, terminate and handle_info callbacks optional in the OTP behaviors. This is very nice. I always wondered why I had to write all that boiler plate code. Also here is a detailed list of changes: http://erlang.org/download/otp_src_20.0-rc2.readme http://erlang.org/download/otp_src_20.0-rc2.readme

fredliu 9y ago
* DTLS : This lets it talk to WebRTC clients Could you elaborate more on this? I don't know much about erlang/OTP's support for WebRTC. Does adding DTLS makes erlang/OTP possible to talk to WebRTC clients because WebRTC requires DTLS? or this means erlang/OTP now has a complete stack and API for WebRTC communication out of the box?
- rdtsc 9y ago
  DTLS is TLS (SSL) but for datagrams (UDP) instead of the traditional streams (TCP). WebRTC uses DTLS as one of its base protocols. The other one is SRTP but even its setup requires DTLS. I am not sure how complete the rest of the support it but having DTLS is a major step ahead.
  - fredliu 9y ago
    Thanks for the clarification. I was aware of the DTLS requirement for WebRTC, but not sure the whole WebRTC stack support on erlang/OTP. Now thinking about it, maybe an erlang/elixir/whatever-on-BEAM implementation of STUN/TURN server would make sense...

brian_herman 9y ago

Is there like a why's poignant guide to ruby for erlang?http://poignant.guide/book/ http://poignant.guide/book/

shadeless 9y ago
There's "Learn You Some Erlang for great good!" (http://learnyousomeerlang.com/ http://learnyousomeerlang.com/), which is a great (the best?) resource for learning Erlang.
- hordeallergy 9y ago
  I found it too densely informative. After the 2nd or 3rd attempt I ditched it and just jumped into programming. Personal preference possibly. I think erlang's difficulty is exaggerated. Just jump in - the immediate little wins will lubricate the process.
  - derefr 9y ago
    "Densely informative" is the right way for a textbook to be, I think. You're not meant to read LYSE or books like it straight through; rather, each individual paragraph is dense enough with facts that after every one, you should stop and tinker with a toy example or two at the REPL to collect your thoughts and make sure you understand what's going on. If you imagine someone teaching Erlang with LYSE serving as the actual textbook, they'd do what is done with most textbooks: split each chapter into rather small segments, and have you do exercises after each one to "interactively" absorb the knowledge.
jmcgough 9y ago
As a rubyist, I found Elixir was a great entrypoint - from there you can learn OTP behaviors like GenServer, and slowly start to learn Erlang syntax from using stuff like its data structures or ETS. Haven't found anything as great as why's guide yet though. Maybe it's just waiting to be written by someone :)
marianoguerra 9y ago

Medaber 9y ago

A better link would be the "What's New" page. https://www.erlang.org/news/112 https://www.erlang.org/news/112

atemerev 9y ago

Erlang is awesome. The only problem preventing me to use it where I want to is terrible file I/O performance, especially on writes. I tried to Google the solution, but it seems that there isn't anything generally accepted for the moment.

marianoguerra 9y ago
something specific? did you tried raw file handles? http://erlang.org/doc/man/file.html#open-2 http://erlang.org/doc/man/file.html#open-2
- atemerev 9y ago
  Yes, and delayed_write as well. I tried to port a (very simplistic, but fast) market data append-only database from Scala to Erlang. In Scala, I have no performance issues, but the code is unnecesarily complex to my taste. In Scala, I am getting around 100000 events per second, with great additional optimization margins (memory mapped files are great). In Erlang, it barely works with few hundred events per second. Right now I have googled that disk_log in Erlang is fast enough, but it uses Erlang's own internal binary format (there is an option to plug custom codecs, but it is wonderfully under-documented, to say the least). This looks strange to me, because Erlang is well-optimized regarding the network IO. What's the difference for file IO?
  - derefr 9y ago
    > Erlang is well-optimized regarding the network IO. What's the difference for file IO? IIRC, async network IO is handled by the VM's scheduler threads each just calling a non-blocking select() on the fdset of sockets it holds port()s for every once in a while. This is because TCP/IP implementations are pretty much guaranteed to expose a non-blocking select() for sockets, and do in every OS Erlang is written for. Disk IO, on the other hand, is done by throwing the calls over to special async IO threads, which have to send responses back to the scheduler that wants them using (I think zero-copy) IPC. This is done because not all OSes have the equivalent of non-blocking select() for file handles (i.e. what you get from using fcntl(2) + read(2) in Linux.) So Erlang's disk IO BIFs fundamentally require context-switches and/or NUMA messaging. You get to avoid this if you use your own NIFs—which have the lovely property of running in the calling scheduler by default, with the ability to decide on each call whether the workload for this particular call is small enough to perform synchronously, or whether it should be scheduled over to a dirty scheduler, blocking the Erlang process and yielding the scheduler. In other words, this is like the disk IO BIFs in the worst case, and can be a lot faster in the best case. It's a lot like NT's "overlapped IO" primitives, actually. You could also use higher-level BIFs. There is a reason Mnesia is implemented in terms of special BIFs (DETS) rather than DETS being a functional layer implemented using the disk IO BIFs. Mind you, DETS probably doesn't have the API you're looking for, but there are a number of NIF libraries that plug low-level "storage engines" into Erlang as NIFs that provide equivalent convenience: • https://github.com/cloudant/nifile https://github.com/cloudant/nifile • https://github.com/basho/eleveldb https://github.com/basho/eleveldb • https://github.com/gburd/lmdb https://github.com/gburd/lmdb And there's also always the option to do what Erlang-on-Xen does: forego anything that "devolves into" disk IO entirely, implementing the file module in terms of network IO—the p9 protocol in their case. This is actually likely the lowest-overhead move you can make if you're going to be running your Erlang node on a VM that would just be talking to a virtual disk mounted from a SAN anyway. Instead of the OS mounting the disk from the SAN and Erlang talking to the OS, you can just have Erlang talk to the SAN directly using e.g. iSCSI.

marianoguerra 9y ago

Also the docs got a facelift: http://erlang.org/doc/ http://erlang.org/doc/ Now that we are talking Erlang: What's missing in Erlang that would be valuable to you? What are the biggest pain points right now on the Erlang ecosystem that makes it harder for you to try it/adopt it?

marianoguerra 9y ago
didn't noticed that the submitted link is to the docs :P
StreamBright 9y ago
For me the biggest pain point was the lack of great libraries for doing basic stuff like HTTP requests (client side). I was not able to reach the performance of Java/JVM with the Erlang implementation and I could not figure out what I am doing wrong. OTP and those pattern associated with it are still a bit opaque after reading countless manuals, howtos and books.
deleted 9y ago
[deleted]
derefr 9y ago
> Also the docs got a facelift You can finally zoom into them on mobile without the sidebar covering half the text :D
- pmontra 9y ago
  They forgot to fix it for Firefox. I guess they're using only Chrome.
digitalzombie 9y ago
> What are the biggest pain points right now on the Erlang ecosystem that makes it harder for you to try it/adopt it? Personally, Erlang solve stuff that is very niche and I don't have any project in those stuff. Elixir web frameworks really help in term of practicing the language. Erlang had cowboy, etc.. but it wasn't close to the other MVC language. So practicing Erlang to get real experiences in it was hard. Maybe there should be a page of examples of other problem Erlang can solve so I can decide which problem I like to start a project on? Cause so far when I think of Erlang it's just concurrency, back end protocol, etc... But I'm sure there may be other problems it can be address that I don't know about and that I would like to start a trivial project on it.

sho 9y ago

My favourite feature - shell history finally in core! That's been a possibly irrational but personally annoying omission for years, and required messy hacks to get around - not a good beginner experience for what I consider to be pretty basic functionality. It's enabled by an envar as described by the hero who cleaned up the hack and ported it here: https://github.com/ferd/erlang-history https://github.com/ferd/erlang-history

marianoguerra 9y ago
yes, that's a great addition. for the lazy: Add `export ERL_AFLAGS="-kernel shell_history enabled"` to your profile and get shell history out of the box with #Erlang/OTP 20 (from https://twitter.com/mononcqc/status/877544929496629248 https://twitter.com/mononcqc/status/877544929496629248)
mononcqc 9y ago
Bit of history on the feature. The hack was an old thing I had written at a hackathon over half a decade ago. It had little cost to regulars who had installed it at least once before. It relied on DETS and had transient issues with corruption of history files, but nothing major enough for anyone to take notice or get mad about it. I myself ended up working on other projects once that one was good enough (including the search function with ctrl+r in the shell -- that wasn't there at first, and then things like rebar3 and other side projects), and nobody really ever took over or reimplemented a better shell history around it, nor took the time to port it to OTP. I had also asked for help in the past for a better implementation that didn't rely on DETS, but not a lot of people were interested or knew how to proceed any better than I did. Eventually I just got tired and reimplemented it with the disk_log module and some log fragmentation and rotation to avoid dropping the whole file every time a limit was reached. It took a few weeks of review to get it in and so far nobody has complained about it. I think the overall lesson is that the moment you have a quick hack to do the job, regulars get used to them, but forget about the beginner's experience where what you have to do is apply all the hacks at once and dear lord does it ever look janky then.
- im_down_w_otp 9y ago

marianoguerra 9y ago

if you want to get started but don't know where this is a good place to start: http://spawnedshelter.com/ http://spawnedshelter.com/ there's a online course by Simon Thompson from the University of Kent that started 2 days ago, you may be able to join: https://www.futurelearn.com/courses/functional-programming-erlang https://www.futurelearn.com/courses/functional-programming-e... if you like the ideas but want to try something different there are alternative languages that run on the Erlang VM: * Elixir with a ruby-like syntax: https://elixir-lang.org/ https://elixir-lang.org/ * LFE (Lisp Flavoured Erlang): http://lfe.io/ http://lfe.io/ * Efene with a python-like syntax: http://efene.org/ http://efene.org/ and one in development but already looking really interesting: Alpaca, an ML inspired language: https://github.com/alpaca-lang/alpaca https://github.com/alpaca-lang/alpaca

dbcurtis 9y ago
Thanks! I came here to ask the "How do I Erlang?" question. Erlang has been on my radar for a long time but I've never taken the time to dig in. 85% of my code output is obscure protocol stacks in Python+Twisted, the other 15% is real-time embedded C over an RTOS. Even if I can't use Erlang in production, I'm sure I'd find food for thought in the concepts.
- digitalzombie 9y ago
  http://learnyousomeerlang.com/ http://learnyousomeerlang.com/ That book is a good place to start. > Even if I can't use Erlang in production, I'm sure I'd find food for thought in the concepts. Oh boy are you going to be in for a treat. The concept for no loop construct other than recursion and recursive thinking was worth it for the little time I dabble in Erlang.
  - equalunique 9y ago
    As an erlang newcomer, the non-loop seems to be one of the most intriguing concepts, IMO.
    - 9y ago

thedaemon 9y ago

Just an FYI Wings3D http://www.wings3d.com/ http://www.wings3d.com/ is built with Erlang. It is a Symbolics style 3d Modelling application using the Winged Edge data structure.

2017throw 9y ago

My favourite DSL!

chx 9y ago

Let's note that Elixir is already compatible with it. Phoenix/Elixir, I feel, is the future of web apps.

pmontra 9y ago
I used to think the same but I'm not sure about it now. We have plenty of managed backends now and they usually support Node, Python and a few other languages [1]. BEAM ones are never among them. Furthermore the deployment story now is all about docker, which is at odds with the mosts advanced features of BEAM (hot reload, but I guess few people use it.) So, it might be the future for fully self managed web apps, but developers are moving in another direction now. That damages the mindshare. [1] Basically the owners of those backends have a voice in which languages succeed and which not. They'll never support more than a handful of languages, because of the maintenance costs.

lokedhs 9y ago

I have tried on multiple occasions to learn and use Erlang for some different projects. My process has always been stopped by a few specific things, and I end up going back to Common Lisp, which tends to be much easier to get to work. My first problem is to make sense out of how to actually run a server application. Manually compiling source files and run functions is one thing, but trying to actually set up an application with all the monitors and stuff is really annoyingly hard. Even following step-by-step instructions resulted in errors that I didn't understand as soon as I tried to do anything outside what the tutorial showed. The second issue that I have never managed to properly solve is how to use libraries. In particular, I have wanted to use the client libraries for RabbitMQ and CouchDB (both written in Erlang, so you'd expect it to be simple). The instructions how to install the libraries usually doesn't match the thing you actually download. I've also tried to use the EDTS in Emacs, which is pretty nice, but as soon as I try to use a library, it can never find the hrl files. I really want to use Erlang, but the difficulty of actually getting started with a real project as opposed to simple tutorial stuff has been extremely frustrating.

JamesUtah07 9y ago
Try out elixir. It runs on the Erlang VM but is easy to get up and running and has a great community. It's much easier to add external libraries and uses its own package manager.
- lokedhs 9y ago
  Thanks for the suggestions (you, and the other two people mentioning the same thing). I have just started looking at Elixir, and I'm hoping that will work better. Am I just to assume that Erlang deployment really is as complicated and poorly documented as I thought, since no one suggested any documentation, but three people suggested I switch to Elixir.
  - klibertp 9y ago
    In my experience, Erlang doesn't have a standard way of doing a deployment. There are 3rd party apps like Rebar and others, but they are both not available by default (after a fresh install) and seriously underdocumented. The result of this, IMHO, is that everyone builds their own build and deployment system, using shell scripting, Make or Erlang itself. Elixir includes Mix - a standard task runner - and Hex as part of the distribution. It also provides a central pkg repository (https://hex.pm/packages https://hex.pm/packages). It's much, much easier to start a project and pull all your dependencies. I guess you could use Hex and Mix with pure Erlang projects, but I haven't tried this.

wtian2000 9y ago

di4na 9y ago

Something that most people seems to have missed > The non SMP Erlang VM is deprecated and not built by default In 2017, most languages are still fighting to get a multicore implementation. Erlang is ditching their single core one.

lngnmn 9y ago

It seems that the source build is broken. At least a straightforward attempt to build otp from github sources with latest clang/lld has been failed.