Drop C extension requirement from JRuby

Rakefile

@@ -17,7 +17,22 @@ if Gem.win_platform?
 end
 
 require 'rake/testtask'
-require 'rake/extensiontask'
+if /java/ === RUBY_PLATFORM
+  # require 'rake/javaextensiontask'
+  # Rake::JavaExtensionTask.new(:hamlit) do |ext|
+  #   ext.ext_dir = 'ext/java'
+  #   ext.lib_dir = 'lib/hamlit'
+  # end
+
+  task :compile do
+    # dummy for now
+  end
+else
+  require 'rake/extensiontask'
+  Rake::ExtensionTask.new(:hamlit) do |ext|
+    ext.lib_dir = 'lib/hamlit'
+  end
+end
 
 Dir['benchmark/*.rake'].each { |b| import(b) }
 
@@ -88,10 +103,6 @@ namespace :test do
   end
 end
 
-Rake::ExtensionTask.new(:hamlit) do |ext|
-  ext.lib_dir = 'lib/hamlit'
-end
-
 desc 'bench task for CI'
 task bench: :compile do
   if ENV['SLIM_BENCH'] == '1'

hamlit.gemspec

@@ -17,9 +17,14 @@ Gem::Specification.new do |spec|
   spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features|sample)/}) }
   spec.bindir        = 'exe'
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
-  spec.extensions    = ['ext/hamlit/extconf.rb']
   spec.require_paths = ['lib']
-  spec.required_ruby_version = '>= 2.1.0'
+
+  if /java/ === RUBY_PLATFORM
+    # spec.platform = 'java'
+  else
+    spec.extensions = ['ext/hamlit/extconf.rb']
+    spec.required_ruby_version = '>= 2.1.0'
+  end
 
   spec.add_dependency 'temple', '>= 0.8.0'
   spec.add_dependency 'thor'

lib/hamlit/attribute_builder.rb

@@ -1,7 +1,9 @@
 # frozen_string_literal: true
-require 'hamlit/hamlit'
-require 'hamlit/object_ref'
+unless /java/ === RUBY_PLATFORM # exclude JRuby
+  require 'hamlit/hamlit'
+end
 require 'hamlit/utils'
+require 'hamlit/object_ref'
 
 module Hamlit::AttributeBuilder
   BOOLEAN_ATTRIBUTES = %w[disabled readonly multiple checked autobuffer

lib/hamlit/utils.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
-require 'hamlit/hamlit'
+unless /java/ === RUBY_PLATFORM # exclude JRuby
+  require 'hamlit/hamlit' # depends on C-ext defines Hamlit::Utils first for now
+end
 
 module Hamlit
   module Utils