Prototype with the Prism parser

benchmark/benchmark_prototype_rb.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require "benchmark/ips"
+require_relative "../lib/rbs"
+
+# Collect Ruby source files to parse
+sources = Dir.glob(File.join(__dir__, "../lib/**/*.rb")).map do |path|
+  [path, File.read(path)]
+end
+
+puts "Benchmarking prototype generation (#{sources.size} files, #{sources.sum { |_, s| s.size }} bytes total)"
+puts
+
+Benchmark.ips do |x|
+  x.report("RB: RubyVM::AbstractSyntaxTree") do
+    ENV.delete("RBS_RUBY_PARSER")
+    sources.each do |_path, source|
+      parser = RBS::Prototype::RB.new
+      parser.parse(source)
+      parser.decls
+    end
+  end
+
+  x.report("RB: Prism") do
+    ENV["RBS_RUBY_PARSER"] = "prism"
+    sources.each do |_path, source|
+      parser = RBS::Prototype::RB.new
+      parser.parse(source)
+      parser.decls
+    end
+  end
+
+  x.compare!
+ensure
+  ENV.delete("RBS_RUBY_PARSER")
+end

lib/rbs.rb

@@ -51,11 +51,16 @@
 require "rbs/resolver/type_name_resolver"
 require "rbs/ast/comment"
 require "rbs/writer"
-require "rbs/prototype/helpers"
+require "rbs/prototype/comment_parser"
+require "rbs/prototype/ruby_vm_helpers"
+require "rbs/prototype/node_usage"
 require "rbs/prototype/rbi"
+require "rbs/prototype/rbi/ruby_vm"
+require "rbs/prototype/rbi/prism"
 require "rbs/prototype/rb"
+require "rbs/prototype/rb/ruby_vm"
+require "rbs/prototype/rb/prism"
 require "rbs/prototype/runtime"
-require "rbs/prototype/node_usage"
 require "rbs/environment_walker"
 require "rbs/vendorer"
 require "rbs/validator"

lib/rbs/prototype/comment_parser.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+module RBS
+  module Prototype
+    module CommentParser
+      # Build a line-number-keyed hash of comments from a Prism::ParseResult or
+      # an array of Prism comment objects.
+      def build_comments_prism(comments, include_trailing:)
+        comments.each_with_object({}) do |comment, hash| #$ Hash[Integer, AST::Comment]
+          next unless comment.is_a?(Prism::InlineComment)
+          next if comment.trailing? && !include_trailing
+
+          line = comment.location.start_line
+          body = "#{comment.location.slice}\n"
+          body = body[2..-1] or raise
+          body = "\n" if body.empty?
+
+          comment = AST::Comment.new(string: body, location: nil)
+          if prev_comment = hash.delete(line - 1)
+            hash[line] = AST::Comment.new(string: prev_comment.string + comment.string, location: nil)
+          else
+            hash[line] = comment
+          end
+        end
+      end
+
+      # Parse comments from a Ruby source string. Uses Prism on Ruby >= 3.3,
+      # falls back to Ripper on older Rubies.
+      if RUBY_VERSION >= "3.3"
+        def parse_comments(string, include_trailing:)
+          build_comments_prism(
+            Prism.parse_comments(string, version: "current"), # steep:ignore UnexpectedKeywordArgument
+            include_trailing: include_trailing
+          )
+        end
+      else
+        require "ripper"
+
+        def parse_comments(string, include_trailing:)
+          Ripper.lex(string).yield_self do |tokens|
+            code_lines = {} #: Hash[Integer, bool]
+            tokens.each.with_object({}) do |token, hash| #$ Hash[Integer, AST::Comment]
+              case token[1]
+              when :on_sp, :on_ignored_nl
+                # skip
+              when :on_comment
+                line = token[0][0]
+                next if code_lines[line] && !include_trailing
+                body = token[2][2..-1] or raise
+
+                body = "\n" if body.empty?
+
+                comment = AST::Comment.new(string: body, location: nil)
+                if prev_comment = hash.delete(line - 1)
+                  hash[line] = AST::Comment.new(string: prev_comment.string + comment.string, location: nil)
+                else
+                  hash[line] = comment
+                end
+              else
+                code_lines[token[0][0]] = true
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end

lib/rbs/prototype/node_usage.rb

@@ -3,7 +3,7 @@
 module RBS
   module Prototype
     class NodeUsage
-      include Helpers
+      include RubyVMHelpers
 
       attr_reader :conditional_nodes