Parser support for no block parameter syntax

Author: kddnewton

bin/prism

@@ -269,17 +269,17 @@ module Prism
 
     # bin/prism parser [source]
     def parser(argv)
-      require "parser/ruby34"
+      require "parser/current"
       source, filepath = read_source(argv)
 
       buffer = Parser::Source::Buffer.new(filepath, 1)
       buffer.source = source
 
       puts "Parser:"
-      parser_parse(Parser::Ruby34.new, buffer)
+      parser_parse(Parser::CurrentRuby.new, buffer)
 
       puts "Prism:"
-      parser_parse(Prism::Translation::Parser34.new, buffer)
+      parser_parse(Prism::Translation::ParserCurrent.new, buffer)
     end
 
     # bin/prism ripper [source]

lib/prism/translation/parser/builder.rb

@@ -7,12 +7,14 @@ 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
-        # It represents the `it` block argument, which is not yet implemented in the Parser gem.
+        # It represents the `it` block argument, which is not yet implemented in
+        # the Parser gem.
         def itarg
           n(:itarg, [:it], nil)
         end
 
-        # The following three lines have been added to support the `it` block parameter syntax in the source code below.
+        # The following three lines have been added to support the `it` block
+        # parameter syntax in the source code below.
         #
         #   if args.type == :itarg
         #     block_type = :itblock
@@ -56,6 +58,12 @@ def block(method_call, begin_t, args, body, end_t)
               method_call.loc.with_expression(join_exprs(method_call, block)))
           end
         end
+
+        # def foo(&nil); end
+        #         ^^^^
+        def blocknilarg(amper_t, nil_t)
+          n0(:blocknilarg, arg_prefix_map(amper_t, nil_t))
+        end
       end
     end
   end

lib/prism/translation/parser/compiler.rb

@@ -1390,6 +1390,12 @@ def visit_nil_node(node)
           builder.nil(token(node.location))
         end
 
+        # def foo(&nil); end
+        #         ^^^^
+        def visit_no_block_parameter_node(node)
+          builder.blocknilarg(token(node.operator_loc), token(node.keyword_loc))
+        end
+
         # def foo(**nil); end
         #         ^^^^^
         def visit_no_keywords_parameter_node(node)