Add a custom builder class for the parser translator

lib/prism/translation/parser.rb

@@ -31,6 +31,11 @@ def initialize(message, level, reason, location)
         end
       end
 
+      # Create the parser with our custom builder class
+      def initialize(builder = Parser::Builder.new)
+        super
+      end
+
       Racc_debug_parser = false # :nodoc:
 
       def version # :nodoc:
@@ -313,6 +318,7 @@ def convert_for_prism(version)
         end
       end
 
+      require_relative "parser/builder"
       require_relative "parser/compiler"
       require_relative "parser/lexer"
 

lib/prism/translation/parser/builder.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Prism
+  module Translation
+    class Parser
+      # A builder that knows how to convert more modern Ruby syntax
+      # into whitequark/parser gem's syntax tree.
+      class Builder < ::Parser::Builders::Default
+
+      end
+    end
+  end
+end

prism.gemspec

@@ -98,6 +98,7 @@ Gem::Specification.new do |spec|
     "lib/prism/translation/parser33.rb",
     "lib/prism/translation/parser34.rb",
     "lib/prism/translation/parser35.rb",
+    "lib/prism/translation/parser/builder.rb",
     "lib/prism/translation/parser/compiler.rb",
     "lib/prism/translation/parser/lexer.rb",
     "lib/prism/translation/ripper.rb",

test/prism/ruby/parser_test.rb

@@ -16,6 +16,7 @@
 
 # First, opt in to every AST feature.
 Parser::Builders::Default.modernize
+Prism::Translation::Parser::Builder.modernize
 
 # The parser gem rejects some strings that would most likely lead to errors
 # in consumers due to encoding problems. RuboCop however monkey-patches this