remove workarounds for Ruby < 2.3

- remove constants for differentiating between Ruby versions
- remove fallback assignment for RUBY_ENGINE constant
- remove rubygems require
- use unicode character properties in regular expressions (e.g., \p{Word})
- remove COERCE_ENCODING constant
- always set FORCE_ENCODING constant to true unless default external encoding is not UTF-8
- remove workaround for computing line length
- use lines method instead of lines.entries to get lines for string
- always normalize lines
- check if JRuby class is defined instead of checking for JRuby engine
- remove global RUBY_ENGINE_JRUBY constant
- move RUBY_ENGINE_OPAL constant inside Asciidoctor module
- remove magic encoding comments (since default script encoding is UTF-8)
- remove workaround when printing encoding information
- remove fallback assignments for passthrough escape characters
- remove Ruby core backports (only leave Asciidoctor-specific extensions)
- use __dir__ instead of File.dirname __FILE__
- use Float#truncate to truncate column widths
- override Float#truncate on Ruby 2.3 to implement precision argument
- remove concurrent/hash backport
- simplify class_for_name helper
- don't call to_sym on constants returned from constants method
- remove unnecessary aliasing of regexp match variables; use magic variable instead (e.g., m = $~)
- remove workaround for sub_specialchars to accomodate gsub with map argument
- remove comment about %:z placeholder for strftime
- don't call .to_a on return value of Hash#keys
- get home directory using Dir.home
- remove exceptions and exclusions for Ruby < 2 in test suite
- update list of supported Ruby engines and versions in READMEs
- update ruby versions in run-tests.sh

2 files changed, 0 insertions, 4 deletions

diff --git a/bin/asciidoctor b/bin/asciidoctor
index ee394296..fa0b32e2 100755
--- a/bin/asciidoctor
+++ b/bin/asciidoctor
@@ -1,7 +1,5 @@
 #!/usr/bin/env ruby
 
-require 'rubygems' unless defined? Gem
-
 if File.exist?(asciidoctor = (File.expand_path '../../lib/asciidoctor', __FILE__))
   require asciidoctor
 else
diff --git a/bin/asciidoctor-safe b/bin/asciidoctor-safe
index 9a70f233..42053271 100755
--- a/bin/asciidoctor-safe
+++ b/bin/asciidoctor-safe
@@ -1,7 +1,5 @@
 #!/usr/bin/env ruby
 
-require 'rubygems' unless defined? Gem
-
 if File.exist?(asciidoctor = (File.expand_path '../../lib/asciidoctor', __FILE__))
   require asciidoctor
 else