v0.20.0

Added

• New acton CLI which takes over as the main acton program, it should be
  called instead of actonc, for example acton build [#1645]
  • it calls into actonc for doing most of the work and is currently mostly
    just a thin wrapper
  • over time, more functionality will be placed in the acton frontend
• New acton test command which build and runs all test in a project [#1645]
• The compiler now does automatic test discovery
  • Simply doing import testing and functions with a name starting with
    _test will be identified as a test and run by acton test. The functions
    are sorted into categories based on their type signature.
• Run-time reconfigurable malloc
  • It is now possible to reconfigure which malloc to use during runtime
  • All external libraries (libuv for example) are now configured to use a
    particular malloc
  • Libraries that did not support a custom alloc have now been extended with
    support for custom malloc.
• Module constants are placed in non-GC heap
  • Using the reconfigurable malloc, we now make use of the "real" malloc (the
    one libc provides) during startup of RTS and up past module init. This means
    all module constants will be placed on the normal heap and not the GC heap.
  • The GC is mark & sweep which means it slows down considerably when there is
    a large live heap.
  • This makes is a viable option to place large amounts of data as module
    constants instead of run time state to speed up programs.
• Fixed size integers arithmetic and comparisons are now unboxed
  • For math heavy programs, this can produce a 4x improvement
  • A lot of witnesses are now unnecessary and thus removed, reducing GC pressure
• testing module has gotten a face lift with much better asserts
  • The assert exceptions now include and print the values
  • Formatting happens in __str__ so performance of exceptions is unchanged
• New snappy module in stdlib [#1655]
  • Snappy is a fast compression library
  • Snappy is written in C++ which implied some changes to build.zig and actonc
• It is now possible to print a .ty file by doing: acton foo.ty
• Improved size & performance of dictionaries
  • An empty dictionary is now completely empty
  • For low number of elements, the dictionary is actually a list with linear
    searching
  • For 5 elements and up, the dict starts to use a hashtable
• KeyError & IndexError now include key / index so it's easier to
  understand what went wrong

Changed

• The Debian package of Acton now depends on libc 2.27 [#1645]
  • Previously depended on the glibc installed on the the build machine (2.36)
    since it was expanded from ${shlibs:Depends}
• Now using Zig 0.12.0-dev.2236
  • the build system has changed somewhat so all build.zig files are updated
• DB backend is now optional, include with acton build --db
• Using newer version of tlsuv library
• RTS main thread now runs special actors, currently just Env
  • This enables us to install signal handlers from Env since this must be
    done from a programs main thread.

Fixed

• dict changed internally to allow storing of None
• Support None in JSON
  • Based on the improved support of dicts
• lstrip, rstrip & setdefault now work properly
• Fix effect of json.encode() and json.decode() [#1654]
  • They are pure!
• Fix testing.test_runner when there are 0 tests to run [#]
• Add tests of client & server in http module
• argparse module now supports nested command parsing
• argparse module now supports -- for literal interpretation of positional
  arguments
• Fix compilation of projects that used TLS
  • We had missed linking in all necessary mbedtls libraries