Erlang/OTP 28.0-rc4 Released

Erlang News & Announcements Erlang News
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OTP 28.0-rc4

Erlang/OTP 28.0-rc4 is the fourth release candidate before the OTP 28.0 release.

The intention with this release is to get feedback from our users.
All feedback is welcome, even if it is only to say that it works for you, and that it installs as it should.
We encourage users to try it out and give us feedback either by creating an issue at
https://github.com/erlang/otp/issues or by posting to Erlang Forums.

All artifacts for the release can be downloaded from the Erlang/OTP Github release
and you can view the new documentation at https://erlang.org/documentation/doc-16-rc4/doc.
You can also install the latest release using kerl like this:

kerl build 28.0-rc4 28.0-rc4

Starting with this release, a source Software Bill of Materials (SBOM)
will describe the release on the Github Releases page. We welcome feedback on the SBOM.

Erlang/OTP 28 is a new major release with new features, improvements
as well as a few incompatibilities. Some of the new features are highlighted below.

Many thanks to all contributors!

Highlights for RC4

  • The ancient ASN.1 modules used in public_key has been replaced with more
    modern versions, but we have strived to keep the documented Erlang API for the
    public_key application compatible.

Highlights for RC2

  • Functionality making it possible for processes to enable reception of
    priority messages has been introduced in accordance with EEP 76.

Highlights for RC1

New language features

  • Comprehensions have been extended with “zip generators” allowing
    multiple generators to be run in parallel. For example,
    [A+B || A <- [1,2,3] && B <- [4,5,6]] will produce [5,7,9].

  • Generators in comprehensions can now be strict, meaning that if
    the generator pattern does not match, an exception will be raised
    instead of silently ignore the value that didn’t match.

  • It is now possible to use any base for floating point numbers as per
    EEP 75: Based Floating Point Literals.

Compiler and JIT improvements

  • For certain types of errors, the compiler can now suggest
    corrections. For example, when attempting to use variable A that
    is not defined but A0 is, the compiler could emit the following
    message: variable 'A' is unbound, did you mean 'A0'?

  • The size of an atom in the Erlang source code was limited to 255
    bytes in previous releases, meaning that an atom containing only
    emojis could contain only 63 emojis. While atoms are still only
    allowed to contain 255 characters, the number of bytes is no longer
    limited.

  • The warn_deprecated_catch option enables warnings for use of
    old-style catch expressions on the form catch Expr instead of the
    modern try … catch … end.

  • Provided that the map argument for a maps:put/3 call is known to
    the compiler to be a map, the compiler will replace such calls with
    the corresponding update using the map syntax.

  • Some BIFs with side-effects (such as binary_to_atom/1) are
    optimized in try … catch in the same way as guard BIFs in
    order to gain performance.

  • The compiler’s alias analysis pass is now both faster and less
    conservative, allowing optimizations of records and binary
    construction to be applied in more cases.

ERTS

  • The trace:system/3 function has been added. It has a similar
    interface as erlang:system_monitor/2 but it also supports trace
    sessions.

  • os:set_signal/2 now supports setting handlers for the SIGWINCH,
    SIGCONT, and SIGINFO signals.

  • The two new BIFs erlang:processes_iterator/0 and
    erlang:process_next/1 make it possible to iterate over the
    process table in a way that scales better than erlang:processes/0.

Shell and terminal

  • The erl -noshell mode has been updated to have two sub modes called
    raw and cooked, where cooked is the old default behaviour and
    raw can be used to bypass the line-editing support of the native
    terminal. Using raw mode it is possible to read keystrokes as they
    occur without the user having to press Enter. Also, the raw mode
    does not echo the typed characters to stdout.

  • The shell now prints a help message explaining how to interrupt a
    running command when stuck executing a command for longer than 5
    seconds.

STDLIB

  • The join(Binaries, Separator) function that joins a list of
    binaries has been added to the binary module.

  • By default, sets created by module sets
    will now be represented as maps.

  • Module re has
    been updated to use the newer PCRE2 library instead of the PCRE library.

  • There is a new zstd module that does Zstandard compression.

Dialyzer

SSL

  • The data handling for tls-v1.3 has been optimized.

Emacs mode (in the Tools application)

  • The indent-region in Emacs command will now handle multiline
    strings better.

For more details about new features and potential incompatibilities see the README.

2 Likes
2

Building after configuring with the --without-wx option resulted in an error:

ERROR: build failed.
 ERLC	../ebin/dbg_wx_filedialog_win.beam
compile: warnings being treated as errors
dbg_wx_filedialog_win.erl:25:2: behaviour wx_object undefined
%   25| -behaviour(wx_object).
%     |  ^

make[3]: *** [../ebin/dbg_wx_filedialog_win.beam] Error 1
make[2]: *** [opt] Error 2
make[1]: *** [opt] Error 2
make: *** [libs] Error 2

This error didn’t occur with the previous 28.0 release candidates.

1 Like
4

The public_key re-write is rather substantial so please test this RC with applications that uses ssl, ssh or public_key.

1 Like