Crystal 0.24.1 has been released!

As any release it includes numerous bugfixes, cool features and performance improvements - in 387 commits since 0.23.1.

0.24.0 was a preview release so this is the canonical realease following 0.23.1.

Exciting Changes

• Added ThinLTO support for LLVM 4.0 and above, which speeds up release builds. It can be activated using the compiler option --lto=thin.
• (breaking-change) SecureRandom is renamed to Random::Secure and SecureRandom.uuid is replaced by a new UUID type, created using UUID.random.
• BigDecimal was added, it offers arbitrary precision, exact decimal numbers. Supplementing BigInt and BigFloat with all three being included using require "big".
• Set instances can now be used as condition for case, matching when the case variable is included in the set.
• (breaking-change) Time::Format more robustly supports parsing sub-second precision.
• Tempfile now supports custom extensions.
• The docs generator outputs documentation as JSON which can be easily parsed and used for external applications. The output directory of the docs generator can be configured using --output flag.
• Garbage collection can be disabled using compiler flag -Dgc_none.
• The default hash function uses an algorithm based on FunnyHash which is resiliant against DoS attacks.
• (breaking-change) HTML.escape only escapes HTML special characters &<>"'. HTML.escape recognizes all HTML5 named entities.
• (breaking-change) Multiple assignment can no longer be used to create an array (a = 1, 2, 3).
• (breaking-change) skip macro method was renamed to skip_file.
• rescue, ensure and else blocks can be used directly in do ...end blocks.

%w(foo bar).each do |x|
  raise x
rescue e
  p e
end

• fun names and lib function calls can now start with uppercase.
• YAML 1.1 core schema is now fully supported.
• Time and Time::Span have nanosecond precision.
• Time.monotonic and Time.measure { ... } allow reading and measuring time using a monotonic clock not influences by time zones, leap seconds and time corrections.
• Crystal.main was added to allow more easily redefining the main of a program.
• Named tuples can be merged using NamedTuple#merge(other : NamedTuple).
• YAML and JSON mappings support presence: true option.
• Dir has two new class methods: children and each_child { ... } which include all entries except . and ...

Other Breaking Changes

• (breaking-change) HTTP::Client#post_form is now HTTP::Client.post(form: ...)
• (breaking-change) Array#reject!, Array#compact! and Array#select! now return self
• (breaking-change) Remove the possibility to require big_int, big_float or big_rational individually: use require \"big\" instead
• (breaking-change) Spec: remove expect_raises without type argument
• (breaking-change) IO is now a class, no longer a module
• (breaking-change) Time constructors now have nanosecond and kind as named argument
• (breaking-change) Removed XML.escape. Use HTML.escape instead
• (breaking-change) Removed macro def
• (breaking-change) To define a custom hash method you must now define hash(hasher)
• (breaking-change) Flate::Reader.new(&block) and Flate::Writer.new(&block) now use the name open
• (breaking-change) Use an Enum for Process stdio redirections
• (breaking-change) Remove ‘$0’ special syntax
• (breaking-change) StaticArray#map and Slice#map now return their same type instead of Array
• (breaking-change) Tuple#map_with_index now returns a Tuple.

Thanks to everyone who supported this release through contributions, reviews and suggestions.

• CHANGELOG
• API Docs
• Milestone 0.24.1