[ANN] ruby_parser 3.13.0 Released

ruby_parser version 3.13.0 has been released!

* home: <https://github.com/seattlerb/ruby_parser>
* bugs: <https://github.com/seattlerb/ruby_parser/issues>
* rdoc: <http://docs.seattlerb.org/ruby_parser>

ruby_parser (RP) is a ruby parser written in pure ruby (utilizing
racc--which does by default use a C extension). RP's output is
the same as ParseTree's output: s-expressions using ruby's arrays and
base types.

As an example:

    def conditional1 arg1
      return 1 if arg1 == 0
      return 0
    end

becomes:

    s(:defn, :conditional1, s(:args, :arg1),
      s(:if,
        s(:call, s(:lvar, :arg1), :==, s(:lit, 0)),
        s(:return, s(:lit, 1)),
        nil),
      s(:return, s(:lit, 0)))

Tested against 801,039 files from the latest of all rubygems (as of 2013-05):

* 1.8 parser is at 99.9739% accuracy, 3.651 sigma
* 1.9 parser is at 99.9940% accuracy, 4.013 sigma
* 2.0 parser is at 99.9939% accuracy, 4.008 sigma

Changes:

### 3.13.0 / 2019-03-12

* 3 major enhancements:

  * Removed 1.8 and 1.9 support. Moved to ruby_parser-legacy gem.
  * Added tentative 2.6 support.
  * Updated ruby_parser.yy to ruby 2.4 architecture.

* 22 minor enhancements:

  * Added debug3 and cmp3 rake tasks that use the above tools.
  * Added tLONELY to compare/normalize.rb
  * Added tools/munge.rb, tools/ripper.rb, and debugging.md
  * 2.6: Added trailing .. and ... support.
  * Extended StackState to log more state changes, making debugging easier.
  * Extended StackState#store to take an initial value.
  * Improved logging / debugging in StackState.
  * Improved normalization and parser compare tasks.
  * Improved tools/munge.rb output.
  * In f_arglist, track in_kwarg if no parens.
  * In process_newline_or_comment, handle NL if in_kwarg there vs normal.
  * Refactored normalized values to WORDLIST.
  * Refactored parser: push up to relop and rel_expr.
  * Removed Keyword.keyword18.
  * Removed RubyLexer version attr_accessors.
  * Removed long dead deprecations internal to RubyParserStuff.
  * Removed version arg to RubyLexer#initialize (default nil + no-op).
  * Renamed Keyword.keyword19 to Keyword.keyword.
  * Renamed process_bracing to process_brace_close
  * Renamed process_curly_brace to process_brace_open
  * Report first parse error message if all parser versions fail, not last.
  * Updated parser to track against 2.6.

* 11 bug fixes:

  * Fix some shift/reduce errors.
  * Fixed BEGIN blocks having different arg value that END blocks. (mvz)
  * Fixed all reported unused non-terminals/rules.
  * Fixed bug 272.
  * Fixed bug in interpolated symbol lists. (strviola)
  * Fixed bug where block shadow arguments were not registered as lvars. (akimd)
  * Fixed bug where kwsplat args weren't treated as lvars. (mvz)
  * Fixed lex_state and other internals in many cases.
  * Fixed shebang in compare/normalize.rb to use env. Avoids rubygems freaking.
  * Fixed some more internal state bugs.
  * Fixed tRCURLY -> tSTRING_DEND for interpolation brace closes.