Move templating logic until YARP

Author: kddnewton

Rakefile

@@ -12,7 +12,7 @@ task default: [:check_manifest, :compile, :test]
 require_relative "templates/template"
 
 desc "Generate all ERB template based files"
-task templates: TEMPLATES
+task templates: YARP::TEMPLATES
 
 def windows?
   RUBY_PLATFORM.include?("mingw")
@@ -59,13 +59,13 @@ elsif RUBY_ENGINE == "jruby"
 end
 
 # So `rake clobber` will delete generated files
-CLOBBER.concat(TEMPLATES)
+CLOBBER.concat(YARP::TEMPLATES)
 CLOBBER.concat(["build"])
 CLOBBER << "lib/yarp/yarp.#{RbConfig::CONFIG["DLEXT"]}"
 
-TEMPLATES.each do |filepath|
+YARP::TEMPLATES.each do |filepath|
   desc "Generate #{filepath}"
   file filepath => ["templates/#{filepath}.erb", "templates/template.rb", "config.yml"] do |t|
-    template(t.name, locals)
+    YARP.template(t.name)
   end
 end

templates/template.rb

@@ -254,81 +254,88 @@ def initialize(config)
   end
 end
 
-# This templates out a file using ERB with the given locals. The locals are
-# derived from the config.yml file.
-def template(name, locals, write_to: nil)
-  filepath = "templates/#{name}.erb"
-  template = File.expand_path("../#{filepath}", __dir__)
-  write_to ||= File.expand_path("../#{name}", __dir__)
-
-  if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
-    erb = ERB.new(File.read(template), trim_mode: "-")
-  else
-    erb = ERB.new(File.read(template), nil, "-")
-  end
-  erb.filename = template
-
-  non_ruby_heading = <<~HEADING
-  /******************************************************************************/
-  /* This file is generated by the templates/template.rb script and should not  */
-  /* be modified manually. See                                                  */
-  /* #{filepath + " " * (74 - filepath.size) } */
-  /* if you are looking to modify the                                           */
-  /* template                                                                   */
-  /******************************************************************************/
-  HEADING
-
-  ruby_heading = <<~HEADING
-  # frozen_string_literal: true
-  =begin
-  This file is generated by the templates/template.rb script and should not be
-  modified manually. See #{filepath}
-  if you are looking to modify the template
-  =end
-
-  HEADING
-
-  heading = if File.extname(filepath.gsub(".erb", "")) == ".rb"
-      ruby_heading
-    else
-      non_ruby_heading
+module YARP
+  class << self
+    # This templates out a file using ERB with the given locals. The locals are
+    # derived from the config.yml file.
+    def template(name, write_to: nil)
+      filepath = "templates/#{name}.erb"
+      template = File.expand_path("../#{filepath}", __dir__)
+      write_to ||= File.expand_path("../#{name}", __dir__)
+
+      if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
+        erb = ERB.new(File.read(template), trim_mode: "-")
+      else
+        erb = ERB.new(File.read(template), nil, "-")
+      end
+      erb.filename = template
+
+      non_ruby_heading = <<~HEADING
+      /******************************************************************************/
+      /* This file is generated by the templates/template.rb script and should not  */
+      /* be modified manually. See                                                  */
+      /* #{filepath + " " * (74 - filepath.size) } */
+      /* if you are looking to modify the                                           */
+      /* template                                                                   */
+      /******************************************************************************/
+      HEADING
+
+      ruby_heading = <<~HEADING
+      # frozen_string_literal: true
+      =begin
+      This file is generated by the templates/template.rb script and should not be
+      modified manually. See #{filepath}
+      if you are looking to modify the template
+      =end
+
+      HEADING
+
+      heading = if File.extname(filepath.gsub(".erb", "")) == ".rb"
+          ruby_heading
+        else
+          non_ruby_heading
+        end
+
+      contents = heading + erb.result_with_hash(locals)
+      FileUtils.mkdir_p(File.dirname(write_to))
+      File.write(write_to, contents)
     end
 
-  contents = heading + erb.result_with_hash(locals)
-  FileUtils.mkdir_p(File.dirname(write_to))
-  File.write(write_to, contents)
-end
-
-def locals
-  config = YAML.load_file(File.expand_path("../config.yml", __dir__))
+    private
+
+    def locals
+      @locals ||=
+        YAML.load_file(File.expand_path("../config.yml", __dir__)).then do |config|
+          {
+            nodes: config.fetch("nodes").map { |node| NodeType.new(node) }.sort_by(&:name),
+            tokens: config.fetch("tokens").map { |token| Token.new(token) },
+            flags: config.fetch("flags").map { |flags| Flags.new(flags) }
+          }
+        end
+    end
+  end
 
-  {
-    nodes: config.fetch("nodes").map { |node| NodeType.new(node) }.sort_by(&:name),
-    tokens: config.fetch("tokens").map { |token| Token.new(token) },
-    flags: config.fetch("flags").map { |flags| Flags.new(flags) }
-  }
+  TEMPLATES = [
+    "ext/yarp/api_node.c",
+    "include/yarp/ast.h",
+    "java/org/yarp/Loader.java",
+    "java/org/yarp/Nodes.java",
+    "java/org/yarp/AbstractNodeVisitor.java",
+    "lib/yarp/mutation_visitor.rb",
+    "lib/yarp/node.rb",
+    "lib/yarp/serialize.rb",
+    "src/node.c",
+    "src/prettyprint.c",
+    "src/serialize.c",
+    "src/token_type.c"
+  ]
 end
 
-TEMPLATES = [
-  "ext/yarp/api_node.c",
-  "include/yarp/ast.h",
-  "java/org/yarp/Loader.java",
-  "java/org/yarp/Nodes.java",
-  "java/org/yarp/AbstractNodeVisitor.java",
-  "lib/yarp/mutation_visitor.rb",
-  "lib/yarp/node.rb",
-  "lib/yarp/serialize.rb",
-  "src/node.c",
-  "src/prettyprint.c",
-  "src/serialize.c",
-  "src/token_type.c"
-]
-
 if __FILE__ == $0
   if ARGV.empty?
-    TEMPLATES.each { |f| template(f, locals) }
+    YARP::TEMPLATES.each { |filepath| YARP.template(filepath) }
   else
     name, write_to = ARGV
-    template(name, locals, write_to: write_to)
+    YARP.template(name, write_to: write_to)
   end
 end