Support Erlang 20 new features

Question

Support Erlang 20 new features

Closed this issue 6 years ago · 27 comments

Answer 1 · 2017-05-07T08:24:06.000Z

List updated with Erlang 20 RC1 notes.

Answer 2 · 2017-05-08T02:06:25.000Z

About unicode atoms, with erlang 20.0-rc1 I found only the quoted syntax is supported:

Erlang/OTP 20 [RELEASE CANDIDATE 1] [erts-9.0] [source-9ac8bdb] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] [kernel-poll:false]

Eshell V9.0  (abort with ^G)
1> 'hello_юникод_世界'.
'hello_юникод_世界'
2> hello_юникод_世界.
* 1: illegal character

am not sure will the unquoted unicode atom be supported in erlang?
when run iex on top of, it's similar that the quoted syntax is already supported, so wonder from here will the unquoted syntax be supported?

Erlang/OTP 20 [RELEASE CANDIDATE 1] [erts-9.0] [source-9ac8bdb] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:10] [hipe] [kernel-poll:false]

Interactive Elixir (1.4.2) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> :"hello_юникод_世界" 
:"hello_юникод_世界"
iex(2)> :hello_юникод_世界
** (SyntaxError) iex:2: unexpected token: "ю" (column 8, codepoint U+044E)

Answer 3 · 2017-05-08T09:21:43.000Z

The plan is exactly to support the unquoted syntax in Elixir.

Answer 4 · 2017-05-08T11:38:49.000Z

@josevalim regarding this:

No longer use regexes in Elixir as they are not portable from 19->20

Can you point to a regex usage example in Elixir source code, the usage of which would have to be cleaned?

Answer 5 · 2017-05-08T11:58:11.000Z

@gmile:

a961bba
588df79
3509ed9

Answer 6 · 2017-06-22T12:54:45.000Z

I saw support for shell history is checked, is it already part of 1.4.5?

Answer 7 · 2017-06-22T13:04:35.000Z

@imranismail there is an open pull request to improve the experience under 1.5 but it does work on 1.4.5 as long as you set an environment variable. See the docs here: #6242.

Answer 8 · 2017-06-22T13:07:38.000Z

Yep just saw a tweet by @ferd about the environment variable

Thank you, will give this a shot

Answer 9 · 2017-11-16T14:06:45.000Z

@josevalim why adding the two new guards require only Erlang 20? Shouldn't it be possible to define the functions with some annotation that they can be used in guards only in Erlang 20? Outside of guards we could simulate them with other calls.

Answer 10 · 2018-02-15T15:12:26.000Z

No longer use outdated rand algorithms (exs1024 -> exs1024s)

Regarding that item should usages of :exsplus also be replaced? If so should they be changed to :exsp or :exrop?

I ask because :exsplus is not listed as one of the three built-in algorithms in the :rand docs.

Answer 11 · 2018-02-15T17:28:25.000Z

@TattdCodeMonkey so we would migrate them all, yeah.

Answer 12 · 2018-03-22T02:56:36.000Z

@josevalim what about OTP-14296?

OTP-14296 Application(s): debugger, stdlib
               The Erlang shell, qlc:string_to_handle(), and the
               Debugger (the Evaluator area and Edit variable window
               of the Bindings area) can parse pids, ports,
               references, and external funs, as long as they can be
               created in the running system.

If I understand, that makes erlang parse PID<0.85.0> and so on correctly. Seems like that could be used in iex once we require OTP 20

Answer 13 · 2018-03-22T07:27:27.000Z

@archseer we don't need to wait for Erlang to support this feature but it is not a feature we are interested into bringing into IEx. Elixir allows any custom data type to be printed as #XYZ<...>, Erlang only handles the built-in types like that and does not allow custom representations, so it is easier for them to tackle this.

Answer 14 · 2018-03-24T05:58:10.000Z

@josevalim Hmm I see, but I'd find it useful personally for at least things like Ports or Refs. I had an issue debugging a library previously that used refs as keys and the logger output printed the faulty key, but since it was a ref I wasn't able to reach it directly. (End solution was to loop over the entire store and compare inspect(ref)). Maybe we could have it available for just system types?

Answer 15 · 2018-03-24T06:18:31.000Z

@archseer you can create pids and refs with the pid and ref helpers in IEx.

Answer 16 · 2018-07-12T11:34:07.000Z

Closing this as we created separate issues for what is pending.

Answer 17 · 2018-07-22T09:48:58.000Z

Environment

Elixir & Erlang versions (elixir --version):
Erlang/OTP 21 [erts-10.0.1] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1]
Elixir 1.6.6 (compiled with OTP 19)
Operating system:
Windows 10
Client (editor or IDE):
vscode

###############
I get the message below on opening elixir phoenix project in vscode:

Dialyzer is disabled because core Elixir modules are missing debug info. You may need to recompile Elixir with Erlang >= OTP 20

I've tried to update elixir but still no luck.

What is recommended? Do I need to rollback Erlang to OTP 19?

Answer 18 · 2018-07-22T14:05:09.000Z

You need to recompile your elixir with erlang OTP 20 or newer. Thats all written in the message.

Alternatively you can of course download a version prebuilt for OTP 20+.

But if you do it or not, you can totally work with your current setup. The warning you see from your editor is just about some ELS-stuff that enables you to get quicker feedback from dialyzer in the editor.

It does not influence your ability to manually run dialyzer. Also it will not affect other functionality of your editor or the language server.

Answer 19 · 2018-07-22T14:28:10.000Z

Well, these are both fresh installed latest oficially released windows versions for erlang and elixir. I just was not sure that everything except the dializer will work as expected. So it will, thanks..

Answer 20 · 2018-07-22T14:35:11.000Z

dialyzer itself will work perfectly fine, only the editor integration does not work. Thats again has nothing to do with elixir. If the message shown is unclear please report this to the vscode-elixir-ls project.

Answer 21 · 2018-07-22T15:24:11.000Z

@igormisha each Elixir version is precompiled with the lowest supported Erlang/OTP version. In this case, Elixir v1.7 is precompiled with Erlang/OTP 19. This is rarely a problem but it is a problem on Erlang/OTP 21 which expects the dialyzer information elsewhere. You can downgrade to Erlang/OTP 19 or 20. Also note this issue won't happen in the next Elixir version, as it requires Erlang/OTP 20+.

Answer 22 · 2018-07-22T18:48:56.000Z

Thanks for the explanation, Jose!

Answer 23 · 2018-08-20T11:57:00.000Z

@josevalim WOuld it be possible to provide two precompiled versions? (the newest and the oldest otp versions)

This breaks dialyzer in all 1.7 elixir docker images.

Answer 24 · 2018-08-20T12:03:13.000Z

Hex.pm team uses bob to provide all elixir versions compiled against all supported major erlang versions. You could use their packages.

https://github.com/hexpm/bob#elixir-builds

Answer 25 · 2018-08-20T12:51:02.000Z

@michalmuskala Thanks, I'll have a look and provide a PR for the image.

Answer 26 · 2018-09-24T14:36:59.000Z

Just want to comment here, if someone will get:

Dialyzer is disabled because core Elixir modules are missing debug info. You may need to recompile Elixir with Erlang >= OTP 20

error in Elixir Language Server with Elixir 1.7 from ASDF and this will be the first link.

As said, Elixir by default ships precompiled with earliest Erlang version - 19.
BUT, we can use any Bob version from asdf Elixir plugin.

Instead:

$ asdf install elixir 1.7

we can use:

$ asdf install elixir 1.7-otp-21

Then in asdf config:

# .tools-versions

elixir 1.7.3-otp-21

This will solve the problem.

Answer 27 · 2018-09-29T05:57:21.000Z

For windows users

go to this link
download master-otp-20.zip

in you folder instalation
C:\Program Files (x86)\Elixir

remove bin, lib, man

and paste master-otp-20.zip files