Try to generate yard doc

.github/workflows/doc.yml

@@ -0,0 +1,23 @@
+name: doc
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ruby
+      - name: Generate document
+        run: bundle exec rake doc
+      - name: Publish Documentation on GitHub Pages
+        uses: peaceiris/actions-gh-pages@v3
+        with:
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          publish_dir: ./doc

.yardopts

@@ -0,0 +1,3 @@
+--plugin rustdoc
+lib
+tmp/doc/candle.json

Gemfile

@@ -6,5 +6,5 @@ gem 'minitest'
 gem 'rake'
 gem 'rake-compiler'
 
-# https://github.com/lsegal/yard/issues/1321
-gem 'yard', require: false
+gem "yard", require: false
+gem 'yard-rustdoc', require: false

Rakefile

@@ -7,8 +7,8 @@ require 'rake/extensiontask'
 task default: :test
 Rake::TestTask.new do |t|
   t.deps << :compile
-  t.libs << "test"
-  t.test_files = FileList["test/**/*_test.rb"]
+  t.libs << 'test'
+  t.test_files = FileList['test/test_*.rb']
 end
 
 spec = Bundler.load_gemspec('candle.gemspec')
@@ -30,3 +30,30 @@ desc 'benchmark'
 task bench: :compile do
   ruby 'test/bench.rb'
 end
+
+namespace :doc do
+  task default: %i[rustdoc yard]
+
+  desc 'Generate YARD documentation'
+  task :yard do
+    sh <<~CMD
+      yard doc \
+        --plugin rustdoc -- lib tmp/doc/candle.json
+    CMD
+  end
+
+  desc 'Generate Rust documentation as JSON'
+  task :rustdoc do
+    sh <<~CMD
+      cargo +nightly rustdoc \
+        --target-dir tmp/doc/target \
+        -p candle \
+        -- -Zunstable-options --output-format json \
+        --document-private-items
+    CMD
+
+    cp "tmp/doc/target/doc/candle.json", "tmp/doc/candle.json"
+  end
+end
+
+task doc: 'doc:default'

test/bench.rb

@@ -1 +1 @@
-puts "Under construction"
+puts 'Under construction'