Add Ruby Next to support older versions (#1)

That would make it possible to use Paco in Ruby Next

.github/workflows/eol.yml

@@ -0,0 +1,60 @@
+name: Build EOL Rubies
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  transpile:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    env:
+      BUNDLE_JOBS: 4
+      BUNDLE_RETRY: 3
+      CI: true
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 3.0
+        bundler-cache: true
+    - name: Transpile Ruby Next
+      run: |
+        bundle exec rake nextify
+    - name: Store transpiled files
+      uses: actions/upload-artifact@v2
+      with:
+        name: ruby-next-transpiled
+        path: lib/.rbnext
+        if-no-files-found: ignore
+
+  build:
+    needs: transpile
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby: [2.2, 2.3, 2.4, 2.5]
+    env:
+      BUNDLE_JOBS: 4
+      BUNDLE_RETRY: 3
+      BUNDLE_GEMFILE: gemfiles/eol.gemfile
+      CI: true
+      EOL: true
+    steps:
+    - uses: actions/checkout@v2
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+        bundler: 1.17
+        bundler-cache: true
+    - name: Restore transpiled files
+      uses: actions/download-artifact@v2
+      with:
+        name: ruby-next-transpiled
+        path: lib/.rbnext
+    - name: Run RSpec
+      run: bundle exec rspec

.gitignore

@@ -11,3 +11,4 @@
 .rspec_status
 
 Gemfile.lock
+/lib/.rbnext

.rbnextrc

@@ -0,0 +1,3 @@
+nextify: |
+  ./lib
+  --min-version=2.2

Gemfile

@@ -9,3 +9,4 @@ gem "rake", "~> 13.0"
 gem "rspec", "~> 3.0"
 gem "simplecov", require: false
 gem "standard"
+gem "ruby-next"

Rakefile

@@ -5,4 +5,9 @@ require "rspec/core/rake_task"
 
 RSpec::Core::RakeTask.new(:spec)
 
+desc "Run Ruby Next nextify"
+task :nextify do
+  sh "bundle exec ruby-next nextify -V"
+end
+
 task default: :spec

gemfiles/eol.gemfile

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+source "https://rubygems.org"
+
+gem "rake", "~> 13.0"
+gem "rspec", "~> 3.0"
+gem "simplecov", require: false
+
+gem "backports"
+
+# Specify your gem's dependencies in paco.gemspec
+gemspec path: ".."

lib/paco.rb

@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+require "ruby-next/language/setup"
+RubyNext::Language.setup_gem_load_path(transpile: true)
+
 require "paco/version"
 require "paco/parse_error"
 require "paco/context"

paco.gemspec

@@ -12,7 +12,7 @@ Gem::Specification.new do |spec|
   spec.description = "Paco is a parser combinator library."
   spec.homepage = "https://github.com/skryukov/paco"
   spec.license = "MIT"
-  spec.required_ruby_version = ">= 2.6.0"
+  spec.required_ruby_version = ">= 2.2.0"
 
   spec.metadata = {
     "bug_tracker_uri" => "#{spec.homepage}/issues",
@@ -22,7 +22,9 @@ Gem::Specification.new do |spec|
     "source_code_uri" => spec.homepage
   }
 
-  spec.files = Dir.glob("lib/**/*") + %w[README.md LICENSE.txt CHANGELOG.md]
+  spec.files = Dir.glob("lib/**/*") + Dir.glob("lib/.rbnext/**/*") + %w[README.md LICENSE.txt CHANGELOG.md]
 
   spec.require_paths = ["lib"]
+
+  spec.add_dependency "ruby-next-core", ">= 0.15.0"
 end

spec/spec_helper.rb

@@ -1,12 +1,16 @@
 # frozen_string_literal: true
 
-require "simplecov"
+if ENV["EOL"] != "true"
+  require "simplecov"
 
-SimpleCov.start do
-  add_filter "/spec/"
-  enable_coverage :branch
+  SimpleCov.start do
+    add_filter "/spec/"
+    enable_coverage :branch
+  end
 end
 
+require "backports/2.5" if ENV["EOL"] == "true"
+
 require "paco"
 require "paco/rspec"