TruffleRuby is a high-performance implementation of the Ruby programming language.
TruffleRuby aims to be fully compatible with the standard implementation of Ruby, MRI, version 2.6.6.

More information is available on the GraalVM website: http://www.graalvm.org/docs/reference-manual/ruby/

Changelog

20.2.0

New features:

• Updated to Ruby 2.6.6.
• Use InteropLibrary#toDisplayString() to better display objects from other languages.
• Implement writing to the top scope for global variables (#2024).
• foreign_object.to_s now uses InteropLibrary#toDisplayString() (and still asString() if isString()).
• foreign_object.inspect has been improved to be more useful (include the language and meta object).
• foreign_object.class now calls getMetaObject() (except for Java classes, same as before).
• Add basic support for Linux ARM64.
• foreign_object.name = value will now call Interoplibrary#writeMember("name", value) instead of invokeMember("name=", value).
• Always show the Ruby core library files in backtraces (#1414).
• The Java stacktrace is now shown when sending SIGQUIT to the process, also on TruffleRuby Native, see Debugging for details (#2041).
• Calls to foreign objects with a block argument will now pass the block as the last argument.
• foreign.name will now use invokeMember if invocable and if not use readMember, see doc/contrib/interop_implicit_api.md for details.
• foreign.to_f and foreign.to_i will now attempt to convert to Ruby Float and Integer (#2038).
• foreign.equal?(other) now uses InteropLibrary#isIdentical(other) and foreign.object_id/__id__ now uses InteropLibrary#identityHashCode().

Bug fixes:

• Fix #class_exec, #module_exec, #instance_eval, and instance_exec to use activated refinements (#1988, @ssnickolay).
• Fixed missing method error for FFI calls with blocking: true when interrupted.
• Use upgraded default gems when installed (#1956).
• Fixed NameError when requiring an autoload path that does not define the autoload constant (#1905).
• Thread local IO buffers are now allocated using a stack to ensure safe operating if a signal handler uses one during an IO operation.
• Fixed TracePoint thread-safety by storing the state on the Ruby Thread (like MRI) instead of inside the TracePoint instance.
• Make require 'rubygems/package' succeed and define Gem::Deprecate correctly (#2014).
• Fix MBCLEN_CHARFOUND_P error.
• Fix rb_enc_str_new when NULL encoding is given with a constant string.
• Fixed rb_enc_precise_mbclen to handle more inputs.
• The output for --engine.TraceCompilation is now significantly easier to read, by having shorter method names and source names (oracle/graal#2052).
• Fix indentation for squiggly heredoc with single quotes (#1564).
• Only print members which are readable for foreign #inspect (#2027).
• Fixed the return value of the first call to Kernel#srand in a Thread (#2028).
• Fix missing flushing when printing an exception at top-level with a custom backtrace, which caused no output being shown (#1750, #1895).
• Use the mode of the given IO for IO#reopen(IO) which is important for the 3 standard IOs (#2034).
• Fix potential deadlock when running finalizers (#2041).
• Let require 'rubygems/specification' work before require 'rubygems'.

Compatibility:

• Implement UnboundMethod#bind_call.
• Implemented ObjectSpace::WeakMap (#1385, #1958).
• Implemented strtod and ruby_strtod (#2007).
• Fix detection of #find_type in FFI to ignore MakeMakefile#find_type from mkmf (#1896, #2010).
• Implemented rb_uv_to_utf8 (#1998, @skateman).
• Implemented rb_str_cat_cstr.
• Implemented rb_fstring.
• Support #refine for Module (#2021, @ssnickolay).
• Implemented rb_ident_hash_new.
• Improved the compatibility of Symbol.all_symbols (#2022, @chrisseaton).
• Implemented rb_enc_str_buf_cat.
• Implemented rb_int_positive_pow.
• Implemented rb_usascii_str_new_lit.
• Define #getch and #getpass on StringIO when io/console is required.
• Implemented rb_uv_to_utf8 (#1998).
• Single character IDs now behave more like those in MRI to improve C extension compatibility, so rb_funcall(a, '+', b) will now do the same thing as in MRI.
• Removed extra public methods on String.
• Implemented rb_array_sort and rb_array_sort_bang.
• Do not create a finalizers Thread if there are other public languages, which is helpful for polyglot cases (#2035).
• Implemented rb_enc_isalnum and rb_enc_isspace.
• RUBY_REVISION is now the full commit hash used to build TruffleRuby, similar to MRI 2.7+.
• Implemented rb_enc_mbc_to_codepoint.
• Changed the lookup methods to achieve Refinements specification (#2033, @ssnickolay)
• Implemented Digest::Instance#new (#2040).
• Implemented ONIGENC_MBC_CASE_FOLD.
• Fixed Thread#raise to call the exception class' constructor with no arguments when given no message (#2045).
• Fixed refine + super compatibility (#2039, #2048, @ssnickolay)
• Make the top-level exception handler more compatible with MRI (#2047).
• Implemented rb_enc_codelen.
• Implemented Ripper by using the C extension (#1585).

Changes:

• RubyGems gem commands updated to use the --no-document option by default.

Performance:

• Enable lazy translation from the parser AST to the Truffle AST for user code by default. This should improve application startup time (#1992).
• instance variable ... not initialized and similar warnings are now optimized to have no peak performance impact if they are not printed (depends on $VERBOSE).
• Implement integer modular exponentiation using BigInteger#mod_pow (#1999, @skateman)
• Fixed a performance issue when computing many substrings of a given non-leaf String with non-US-ASCII characters.
• Speedup native handle to Ruby object lookup for C extensions.