v0.18.0

Added

• Exceptions now have a __str__() method used to print the exception
  • useful for exception types where we want to be able to include dynamic data
  • string formatting of dynamic log messages is expensive, so we don't want to
    incur that cost for exceptions that are thrown but never printed
  • add extra attributes and print them in __str__() in your custom exceptions
• Add testing module [#1524] [#1552]
  • Supports four categories of tests:
    • unit tests: proc() -> None, think pure functions
    • synchronous actor tests, involves actors
    • asynchronous actor tests
    • env tests
• Improvement to type error messages [#1554] [#1556] [#1559]
• Add term module
  • a couple of small helpers for doing colored text and similar in terminals
• Add random.choice() & random.choice() [#1541]
• Add printn() is like print but prints without an ending newline
  • also flushes output immediately, useful to print progress style output
  • this is temporary and will be removed once default argument handling is
    properly implemented
• Add math.pi = 3.141592653589793 [#1539]
• acton.rts.enable_gc() & acton.rts.disable_gc()
  • there are situations in which it can be useful to turn off the GC, such as
    during certain test scenarios
• acton.rts.get_mem_usage() returns memory usage [#]
  • approximate output due to how the GC works
• Add uri module [#1560]
  • Features a parse_http() function to parse a HTTP URL into its parts

Changed

• Reverted to global single threaded malloc [#1547]
  • There have been some reports of errors that could potentially be related to
    per-thread malloc or DNS lookups. In caution, the per-thread malloc has been
    disabled and will be brought back in a safe way once we've been able to test
    it much more thoroughly.
• Integer division by zero now results in exception ZeroDivisionError
  • for float, inf is returned [#1530]
    • this is aligned with IEEE & languages like C, Zig, Rust, Swift, Julia
    • Python raises an exception on float divide by zero
• Haskell Stack updated to LTS 21.13 using GHC 9.4 [#1517]
  • Some tests show actonc running ~25% faster
    • Presumably thanks to more optimizations in ghc
  • C++ seemingly pulled in as a dependency for building Acton itself :(
    • Would be nice to use zig c++ but alas, that does not work
• actonc now always built statically on Linux
  • Previously it was only built statically in release mode
  • It does emit some errors / warnings around using dlopen but those are
    harmless and can be ignored in our case
• commands in argparse now expect proc() rather than pure()
• JSON encode/decode are now free functions [#1536]
  • the JSON encode and decode functions were implemented as methods on an actor
    due to an earlier actonc bug
  • bug is fixed, so encode() and decode() are now moved to free functions
    in the json module
  • the old Json actor remains and simply wraps the free functions

Fixed

• Fix error handling in net.TCPConnection for single family use [#1546]
  • original error handling presumed a dual stack socket and so would wait for
    both IPv4 and IPv6 to report an error before propagating the error to the
    caller
  • now if only a single address family is used, errors are immediately sent to
    the caller
• Fix error handling in net.TCPConnection for dual stack use [#1527]
  • while the original design focused on this use case, there was a bug
• Honor --root
  • the automatic detection of root actors based on the name main would
    previously override a manually provided one
• Fix time difference calculation when underflowing
• Fix add / sub duration & comparison for time.Instant [#1545]
• Fix premature conversion of input to close converter [#1553]

Testing / CI

• Now building .debs on Debian 12 / bookworm
• Avoid DNS lookups in test [#1551]
  • We have a likely bug around DNS lookups that hits on MacOS. Work around by
    using "127.0.0.1" rather than "localhost" in tests.