require 'asciidoctor/core_ext/nil_or_empty'
if RUBY_MIN_VERSION_1_9
  require 'asciidoctor/core_ext/string/limit'
elsif RUBY_ENGINE != 'opal'
  require 'asciidoctor/core_ext/1.8.7/string/chr'
  require 'asciidoctor/core_ext/1.8.7/string/limit'
  require 'asciidoctor/core_ext/1.8.7/symbol/length'
end