Implement if-else

Rakefile

@@ -6,7 +6,9 @@
 require 'open3'
 require 'rake/clean'
 
-STAGES = Dir.glob('boot/stage*.elna').collect { |stage| File.basename stage, '.elna' }.sort
+STAGES = Dir.glob('boot/stage*.elna')
+  .collect { |stage| File.basename stage, '.elna' }
+  .sort { |a, b| a.delete_prefix('stage').to_i <=> b.delete_prefix('stage').to_i }
 
 CLEAN.include 'build/boot', 'build/valid'
 
@@ -39,17 +41,9 @@ end
 
 desc 'Convert previous stage language into the current stage language'
 task :convert do
-  File.open('boot/stage9.elna', 'w') do |current_stage|
-    File.readlines('boot/stage8.elna').each do |line|
-      comment_match = /^(\s*)#(.*)/.match line
-
-      if comment_match.nil?
-        current_stage << line
-      elsif comment_match[2].empty?
-        current_stage << "\n"
-      else
-        current_stage << "#{comment_match[1]}(* #{comment_match[2].strip} *)\n"
-      end
+  File.open('boot/stage10.elna', 'w') do |current_stage|
+    File.readlines('boot/stage9.elna').each do |line|
+      current_stage << line
     end
   end
 end