diff --git a/Gemfile b/Gemfile
index 79b7ff9a6..4ae4ee59f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,7 @@ gem "test-unit"
 gem "rspec"
 gem "rubocop"
 gem "rubocop-rubycw"
-gem "rubocop-on-rbs"
+gem "rubocop-on-rbs", platform: :ruby # zlib transitive dep
 gem "json"
 gem "json-schema"
 gem "goodcheck"
@@ -28,15 +28,15 @@ group :libs do
   gem "abbrev"
   gem "base64"
   gem "bigdecimal"
-  gem "dbm"
+  gem "dbm", platform: :ruby
   gem "mutex_m"
   gem "nkf"
 end
 
 group :profilers do
   # Performance profiling and benchmarking
-  gem 'stackprof'
-  gem 'memory_profiler'
+  gem 'stackprof', platform: :ruby
+  gem 'memory_profiler', platform: :ruby
   gem 'benchmark-ips'
   gem "ruby_memcheck", platform: :ruby
 end
diff --git a/include/rbs/defines.h b/include/rbs/defines.h
index 1f24e3c67..0ca4ab386 100644
--- a/include/rbs/defines.h
+++ b/include/rbs/defines.h
@@ -83,4 +83,19 @@
 #define RBS_ATTRIBUTE_UNUSED
 #endif
 
+/***********************************************************************************************************************
+ * Exported functions from dynamic lib                                                                                 *
+ **********************************************************************************************************************/
+#ifndef RBS_EXPORTED_FUNCTION
+#   ifdef RBS_EXPORT_SYMBOLS
+#       ifdef _WIN32
+#          define RBS_EXPORTED_FUNCTION __declspec(dllexport) extern
+#       else
+#          define RBS_EXPORTED_FUNCTION __attribute__((__visibility__("default"))) extern
+#       endif
+#   else
+#       define RBS_EXPORTED_FUNCTION
+#   endif
+#endif
+
 #endif
diff --git a/include/rbs/parser.h b/include/rbs/parser.h
index efb06ebe5..55acf560a 100644
--- a/include/rbs/parser.h
+++ b/include/rbs/parser.h
@@ -99,7 +99,9 @@ rbs_lexer_t *rbs_lexer_new(rbs_allocator_t *, rbs_string_t string, const rbs_enc
  * rbs_parser_new(buffer, string, encoding, 0, 1);
  * ```
  * */
+RBS_EXPORTED_FUNCTION
 rbs_parser_t *rbs_parser_new(rbs_string_t string, const rbs_encoding_t *encoding, int start_pos, int end_pos);
+RBS_EXPORTED_FUNCTION
 void rbs_parser_free(rbs_parser_t *parser);
 
 /**
@@ -126,8 +128,10 @@ rbs_ast_comment_t *rbs_parser_get_comment(rbs_parser_t *parser, int subject_line
 
 void rbs_parser_set_error(rbs_parser_t *parser, rbs_token_t tok, bool syntax_error, const char *fmt, ...) RBS_ATTRIBUTE_FORMAT(4, 5);
 
+RBS_EXPORTED_FUNCTION
 bool rbs_parse_type(rbs_parser_t *parser, rbs_node_t **type, bool void_allowed, bool self_allowed, bool classish_allowed);
 bool rbs_parse_method_type(rbs_parser_t *parser, rbs_method_type_t **method_type, bool require_eof, bool classish_allowed);
+RBS_EXPORTED_FUNCTION
 bool rbs_parse_signature(rbs_parser_t *parser, rbs_signature_t **signature);
 
 bool rbs_parse_type_params(rbs_parser_t *parser, bool module_type_params, rbs_node_list_t **params);
diff --git a/include/rbs/util/rbs_constant_pool.h b/include/rbs/util/rbs_constant_pool.h
index 30d569f61..81ff085d8 100644
--- a/include/rbs/util/rbs_constant_pool.h
+++ b/include/rbs/util/rbs_constant_pool.h
@@ -82,6 +82,7 @@ typedef struct {
 } rbs_constant_pool_t;
 
 // A global constant pool for storing permenant keywords, such as the names of location children in `parser.c`.
+RBS_EXPORTED_FUNCTION
 extern rbs_constant_pool_t *RBS_GLOBAL_CONSTANT_POOL;
 
 /**
@@ -91,6 +92,7 @@ extern rbs_constant_pool_t *RBS_GLOBAL_CONSTANT_POOL;
  * @param capacity The initial capacity of the pool.
  * @return Whether the initialization succeeded.
  */
+RBS_EXPORTED_FUNCTION
 bool rbs_constant_pool_init(rbs_constant_pool_t *pool, uint32_t capacity);
 
 /**
diff --git a/include/rbs/util/rbs_encoding.h b/include/rbs/util/rbs_encoding.h
index 59f99c7af..1cbdfb4ad 100644
--- a/include/rbs/util/rbs_encoding.h
+++ b/include/rbs/util/rbs_encoding.h
@@ -277,6 +277,7 @@ extern const rbs_encoding_t rbs_encodings[RBS_ENCODING_MAXIMUM];
  * @param end A pointer to the last byte of the name.
  * @returns A pointer to the encoding struct if one is found, otherwise NULL.
  */
+RBS_EXPORTED_FUNCTION
 const rbs_encoding_t *rbs_encoding_find(const uint8_t *start, const uint8_t *end);
 
 #endif
diff --git a/lib/rbs.rb b/lib/rbs.rb
index 197d5f703..d2b04d366 100644
--- a/lib/rbs.rb
+++ b/lib/rbs.rb
@@ -69,7 +69,12 @@
 require "rbs/type_alias_regularity"
 require "rbs/collection"
 
-require "rbs_extension"
+begin
+  require "rbs_extension"
+rescue LoadError
+  require "rbs/ffi/parser"
+  require "rbs/ffi/location"
+end
 require "rbs/parser_aux"
 require "rbs/location_aux"
 
diff --git a/lib/rbs/ffi/location.rb b/lib/rbs/ffi/location.rb
new file mode 100644
index 000000000..ca4686553
--- /dev/null
+++ b/lib/rbs/ffi/location.rb
@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+module RBS
+  class Location
+    def initialize(buffer, start_pos, end_pos)
+
+    end
+
+    def initialize_copy(other)
+
+    end
+
+    def buffer
+
+    end
+
+    def _start_pos
+
+    end
+
+    def _end_pos
+
+    end
+
+    def _add_required_child(name, start, end_pos)
+
+    end
+
+    def _add_optional_child(name, start, end_pos)
+
+    end
+
+    def _add_optional_no_child(name)
+
+    end
+
+    def _optional_keys
+
+    end
+
+    def _required_keys
+
+    end
+
+    def [](name)
+
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/rbs/ffi/parser.rb b/lib/rbs/ffi/parser.rb
new file mode 100644
index 000000000..1df1bab2f
--- /dev/null
+++ b/lib/rbs/ffi/parser.rb
@@ -0,0 +1,942 @@
+# frozen_string_literal: true
+require 'ffi'
+
+module RBS
+
+  module Native
+    extend FFI::Library
+
+    ffi_lib "librbs.dylib"
+
+    NodeType = enum(
+        :ast_annotation, 1,
+        :ast_bool, 2,
+        :ast_comment, 3,
+        :ast_declarations_class, 4,
+        :ast_declarations_class_super, 5,
+        :ast_declarations_class_alias, 6,
+        :ast_declarations_constant, 7,
+        :ast_declarations_global, 8,
+        :ast_declarations_interface, 9,
+        :ast_declarations_module, 10,
+        :ast_declarations_module_self, 11,
+        :ast_declarations_module_alias, 12,
+        :ast_declarations_type_alias, 13,
+        :ast_directives_use, 14,
+        :ast_directives_use_single_clause, 15,
+        :ast_directives_use_wildcard_clause, 16,
+        :ast_integer, 17,
+        :ast_members_alias, 18,
+        :ast_members_attr_accessor, 19,
+        :ast_members_attr_reader, 20,
+        :ast_members_attr_writer, 21,
+        :ast_members_class_instance_variable, 22,
+        :ast_members_class_variable, 23,
+        :ast_members_extend, 24,
+        :ast_members_include, 25,
+        :ast_members_instance_variable, 26,
+        :ast_members_method_definition, 27,
+        :ast_members_method_definition_overload, 28,
+        :ast_members_prepend, 29,
+        :ast_members_private, 30,
+        :ast_members_public, 31,
+        :ast_ruby_annotations_class_alias_annotation, 32,
+        :ast_ruby_annotations_colon_method_type_annotation, 33,
+        :ast_ruby_annotations_instance_variable_annotation, 34,
+        :ast_ruby_annotations_method_types_annotation, 35,
+        :ast_ruby_annotations_module_alias_annotation, 36,
+        :ast_ruby_annotations_node_type_assertion, 37,
+        :ast_ruby_annotations_return_type_annotation, 38,
+        :ast_ruby_annotations_skip_annotation, 39,
+        :ast_ruby_annotations_type_application_annotation, 40,
+        :ast_string, 41,
+        :ast_type_param, 42,
+        :method_type, 43,
+        :namespace, 44,
+        :signature, 45,
+        :type_name, 46,
+        :types_alias, 47,
+        :types_bases_any, 48,
+        :types_bases_bool, 49,
+        :types_bases_bottom, 50,
+        :types_bases_class, 51,
+        :types_bases_instance, 52,
+        :types_bases_nil, 53,
+        :types_bases_self, 54,
+        :types_bases_top, 55,
+        :types_bases_void, 56,
+        :types_block, 57,
+        :types_class_instance, 58,
+        :types_class_singleton, 59,
+        :types_function, 60,
+        :types_function_param, 61,
+        :types_interface, 62,
+        :types_intersection, 63,
+        :types_literal, 64,
+        :types_optional, 65,
+        :types_proc, 66,
+        :types_record, 67,
+        :types_record_field_type, 68,
+        :types_tuple, 69,
+        :types_union, 70,
+        :types_untyped_function, 71,
+        :types_variable, 72,
+        :keyword,
+        :symbol,
+    )
+
+    module StructUtils
+      def safe_get(name)
+        value = self[name]
+        if value.respond_to?(:null?) && value.null?
+          value = nil
+        end
+        value
+      end
+
+      def inspect
+        str = "#<#{self.class}"
+        members.each do
+          str << " #{it}=#{safe_get(it).inspect}"
+        end
+        str << ">"
+        str
+      end
+    end
+
+    class StringPointer < FFI::Struct
+      include StructUtils
+
+      layout :start, :pointer, :end, :pointer
+
+      def self.new(str)
+        str_ptr = super()
+        @ptr = FFI::MemoryPointer.from_string(str)
+        str_ptr[:start] = @ptr
+        str_ptr[:end] = @ptr + str.length
+        str_ptr
+      end
+    end
+
+    typedef :uint32, :constant_id
+
+    class Position < FFI::Struct
+      include StructUtils
+
+      layout :byte_pos, :int32,
+             :char_pos, :int32,
+             :line, :int32,
+             :column, :int32
+    end
+
+    class Range < FFI::Struct
+      include StructUtils
+
+      layout :start, Position,
+             :end, Position
+    end
+
+    class LocRange < FFI::Struct
+      include StructUtils
+
+      layout :start, :int32,
+             :end, :int32
+    end
+
+    class LocEntry < FFI::Struct
+      include StructUtils
+
+      layout :name, :constant_id,
+             :range, LocRange
+    end
+
+    typedef :uint32, :loc_entry_bitmap
+
+    class LocChildren < FFI::Struct
+      include StructUtils
+
+      layout :len, :uint16,
+             :cap, :uint16,
+             :required_p, :loc_entry_bitmap,
+             :entries, [LocEntry, 1]
+    end
+
+    class Location < FFI::Struct
+      include StructUtils
+
+      layout :rg, Range,
+             :children, LocChildren.ptr
+    end
+
+    class LocationListNode < FFI::Struct
+      include StructUtils
+
+      layout :loc, Location.ptr,
+             :next, :pointer # LocationListNode
+    end
+
+    class LocationList < FFI::Struct
+      include StructUtils
+
+      layout :allocator, :pointer,
+             :head, LocationListNode.ptr,
+             :tail, :pointer, # LocationListNode
+             :length, :size_t
+    end
+
+    class Node < FFI::Struct
+      include StructUtils
+
+      layout :type, :uint8, :location, Location.ptr
+    end
+
+    class NodeListNode < FFI::Struct
+      include StructUtils
+
+      layout :node, Node.ptr, :next, :pointer
+    end
+
+    class NodeList < FFI::Struct
+      include StructUtils
+
+      layout :allocator, :pointer, :head, NodeListNode.ptr, :tail, NodeListNode.ptr, :length, :size_t
+
+      def to_a
+        ary = []
+        each do |node|
+          ary << node
+        end
+        ary
+      end
+
+      def each
+        node = self.safe_get(:head)
+        while node
+          yield node
+          nxt = node[:next]
+          break if nxt.address == 0
+          node = NodeListNode.new(nxt)
+        end
+      end
+    end
+
+    class HashNode < FFI::Struct
+      include StructUtils
+
+      layout :key, Node.ptr,
+             :value, Node.ptr,
+             :next, :pointer # HashNode
+    end
+
+    class Hash < FFI::Struct
+      include StructUtils
+
+      layout :allocator, :pointer,
+             :head, HashNode,
+             :tail, :pointer,
+             :length, :size_t
+    end
+
+    class Namespace < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :path, NodeList.ptr,
+             :absolute, :bool
+    end
+
+    class ASTSymbol < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :constant_id, :constant_id
+    end
+
+    class TypeName < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :rbs_namespace, Namespace.ptr,
+             :name, ASTSymbol.ptr
+    end
+
+    class ASTAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :string, StringPointer
+    end
+
+    class ASTBool < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :value, :bool
+    end
+
+    class ASTComment < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :string, StringPointer
+    end
+
+    class ASTDeclarationsClassSuper < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :new_name, TypeName.ptr,
+             :old_name, TypeName.ptr,
+             :comment, ASTComment.ptr,
+             :anotations, NodeList.ptr
+    end
+
+    class ASTDeclarationsClass < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :type_params, NodeList.ptr,
+             :super_class, ASTDeclarationsClassSuper.ptr,
+             :members, NodeList.ptr, :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTDeclarationsGlobal < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :type, Node.ptr,
+             :comment, ASTComment.ptr,
+             :annotations, NodeList.ptr
+    end
+
+    class ASTDeclarationsInterface < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :type_params, NodeList.ptr,
+             :members, NodeList.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTDeclarationsModule < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :args, NodeList.ptr,
+             :self_types, NodeList.ptr,
+             :members, NodeList.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTDeclarationsModuleSelf < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :args, NodeList.ptr
+    end
+
+    class ASTDeclarationsModuleAlias < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :new_name, TypeName.ptr,
+             :old_name, TypeName.ptr,
+             :comment, ASTComment.ptr,
+             :annotations, NodeList.ptr
+    end
+
+    class ASTDeclarationsTypeAlias < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :type_params, NodeList.ptr,
+             :type, Node.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTDeclarationsUse < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :clauses, NodeList.ptr
+    end
+
+    class ASTDeclarationsUseSingleClause < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type_name, TypeName.ptr,
+             :new_name, ASTSymbol.ptr
+    end
+
+    class ASTDirectivesUseWildcardClause < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :namespace, Namespace.ptr
+    end
+
+    class ASTInteger < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :string_representation, StringPointer.ptr
+    end
+
+    class Keyword < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :constant_id, :constant_id
+    end
+
+    class ASTMembersAlias < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :new_name, ASTSymbol.ptr,
+             :old_name, ASTSymbol.ptr,
+             :kind, Keyword.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTMembersAttrAccessor < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :type, Node.ptr,
+             :ivar_name, Node.ptr,
+             :kind, Keyword.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr,
+             :visibility, Keyword.ptr
+    end
+
+    class ASTMembersAttReader < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :type, Node.ptr,
+             :ivar_name, Node.ptr,
+             :kind, Keyword.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr,
+             :visibility, Keyword.ptr
+    end
+
+    class ASTMembersAttWriter < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :type, Node.ptr,
+             :ivar_name, Node.ptr,
+             :kind, Keyword.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr,
+             :visibility, Keyword.ptr
+    end
+
+    class ASTMembersClassInstanceVariable < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :type, Node.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTMembersExtend < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :args, NodeList.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTMembersInclude < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :args, NodeList.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTMembersInstanceVariable < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :type, Node.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTMembersMethodDefinition < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :kind, Keyword.ptr,
+             :overloads, NodeList.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr,
+             :overloading, :bool,
+             :visibility, Keyword.ptr
+    end
+
+    class ASTMembersMethodDefinitionOverload < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :annotations, NodeList.ptr,
+             :method_type, Node.ptr
+    end
+
+    class ASTMembersPrepend < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :node_list, NodeList.ptr,
+             :annotations, NodeList.ptr,
+             :comment, ASTComment.ptr
+    end
+
+    class ASTMembersPrivate < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class ASTMembersPublic < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class Token < FFI::Struct
+      include StructUtils
+
+      layout :type, :uint8, # RBSTokenType enum
+             :range, Range
+    end
+
+    class ASTRubyAnnotationsClassAliasAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :keyword_location, Location.ptr,
+             :type_name, TypeName.ptr,
+             :location, Location.ptr
+    end
+
+    class ASTRubyAnnotationsColonMethodTypeAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :annotations, NodeList.ptr,
+             :method_type, Node.ptr
+    end
+
+    class ASTRubyAnnotationsInstanceVariableAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :ivar_name, ASTSymbol.ptr,
+             :ivar_name_location, Location.ptr,
+             :colon_location, Location.ptr,
+             :type, Node.ptr,
+             :comment_location, Location.ptr
+    end
+
+    class ASTRubyAnnotationsMethodTypesAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :overloads, NodeList.ptr,
+             :vertical_bar_locations, LocationList.ptr
+    end
+
+    class ASTRubyAnnotationsModuleAliasAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :keyword_location, Location.ptr,
+             :type_name, TypeName.ptr,
+             :type_name_location, Location.ptr
+    end
+
+    class ASTRubyAnnotationsNodeTypeAssertion < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :type, Node.ptr
+    end
+
+    class ASTRubyAnnotationsReturnTypeAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :return_location, Location.ptr,
+             :colon_location, Location.ptr,
+             :return_type, TypeName.ptr,
+             :comment_location, Location.ptr
+    end
+
+    class ASTRubyAnnotationsSkipAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :skip_location, Location.ptr,
+             :comment_location, Location.ptr
+    end
+
+    class ASTRubyAnnotationsTypeApplicationAnnotation < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :prefix_location, Location.ptr,
+             :type_args, NodeList.ptr,
+             :close_bracket_location, Location.ptr,
+             :comma_locations, Location.ptr
+    end
+
+    class ASTString < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :string, StringPointer.ptr
+    end
+
+    class ASTTypeParam < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr,
+             :variance, Keyword.ptr,
+             :upper_bound, Node.ptr,
+             :lower_bound, Node.ptr,
+             :default_type, Node.ptr,
+             :unchecked, :bool
+    end
+
+    class TypesBlock < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type, Node.ptr,
+             :required, :bool,
+             :self_type, Node.ptr
+    end
+
+    class MethodType < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type_params, NodeList.ptr,
+             :type, Node.ptr,
+             :block, TypesBlock.ptr
+    end
+
+    class Signature < FFI::Struct
+      include StructUtils
+
+      layout :base, Node, :directives, NodeList.ptr, :declarations, NodeList.ptr
+
+      def inspect
+        [base, directives, declarations].inspect
+      end
+
+      def base
+        self.safe_get(:base)
+      end
+
+      def directives
+        self.safe_get(:directives)
+      end
+
+      def declarations
+        self.safe_get(:declarations)
+      end
+    end
+
+    class TypesAlias < FFI::Struct
+      include StructUtils
+      
+      layout :base, Node,
+             :type_name, TypeName.ptr,
+             :args, NodeList.ptr
+    end
+
+    class TypesBasesAny < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :todo, :bool
+    end
+
+    class TypesBasesBool < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesBottom < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesClasses < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesInstance < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesNil < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesSelf < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesTop < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesBasesVoid < FFI::Struct
+      include StructUtils
+
+      layout :base, Node
+    end
+
+    class TypesClassInstance < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr,
+             :args, NodeList.ptr
+    end
+
+    class TypesClassSingleton < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, TypeName.ptr
+    end
+
+    class TypesFunction < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :required_positionals, NodeList.ptr,
+             :optional_positionals, NodeList.ptr,
+             :rest_positionals, Node.ptr,
+             :trailing_positionals, NodeList.ptr,
+             :required_keywords, Hash.ptr,
+             :optional_keywords, Hash.ptr,
+             :rest_keywords, Node.ptr,
+             :return_type, Node.ptr
+    end
+
+    class TypesFunctionParam < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type, Node.ptr,
+             :name, ASTSymbol.ptr
+    end
+
+    class TypesInterface < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type, Node.ptr,
+             :args, NodeList.ptr
+    end
+
+    class TypesIntersection < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :types, NodeList.ptr
+    end
+
+    class TypesLiteral < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :literal, Node.ptr
+    end
+
+    class TypesOptional < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type, Node.ptr
+    end
+
+    class TypesProc < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type, Node.ptr,
+             :block, TypesBlock.ptr,
+             :self_type, Node.ptr
+    end
+
+    class TypesRecord < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :all_fields, Hash.ptr
+    end
+
+    class TypesRecordFieldType < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :type, Node.ptr,
+             :required, :bool
+    end
+
+    class TypesTuple < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :types, NodeList.ptr
+    end
+
+    class TypesUnion < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :types, NodeList.ptr
+    end
+
+    class TypesUntypedFunction < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :return_type, Node.ptr
+    end
+
+    class TypesVariable < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :name, ASTSymbol.ptr
+    end
+
+    class ASTRubyAnnotations < FFI::Struct
+      include StructUtils
+
+      layout :base, Node,
+             :colon_method_type_annotation, ASTRubyAnnotationsColonMethodTypeAnnotation.ptr,
+             :method_types_annotation, ASTRubyAnnotationsMethodTypesAnnotation.ptr,
+             :node_type_assertion, ASTRubyAnnotationsNodeTypeAssertion.ptr,
+             :return_type_annotation, ASTRubyAnnotationsReturnTypeAnnotation.ptr,
+             :skip_annotation, ASTRubyAnnotationsSkipAnnotation.ptr
+    end
+
+    attach_function :rbs_encoding_find, [:pointer, :pointer], :pointer
+
+    attach_function :rbs_parser_new, [StringPointer.by_value, :pointer, :int32, :int32], :pointer
+    attach_function :rbs_parser_free, [:pointer], :void
+    attach_function :rbs_parse_type, [:pointer, :pointer, :bool, :bool, :bool], :bool
+    attach_function :rbs_parse_signature, [:pointer, :pointer], :bool
+    attach_function :rbs_constant_pool_init, [:pointer, :uint32], :bool
+    attach_variable :RBS_GLOBAL_CONSTANT_POOL, :pointer
+  end
+
+  Native.rbs_constant_pool_init(Native.RBS_GLOBAL_CONSTANT_POOL, 7)
+
+  class Parser
+
+    def self.new_parser(str, start_pos, end_pos)
+      buffer = Native::StringPointer.new(str)
+      enc = str.encoding.name
+      encoding_ptr = FFI::MemoryPointer.from_string(enc)
+      rbs_encoding = Native.rbs_encoding_find(encoding_ptr, encoding_ptr + enc.length)
+      Native.rbs_parser_new buffer, rbs_encoding, start_pos, end_pos
+    end
+
+    def self.free_parser(parser)
+      Native.rbs_parser_free parser
+    end
+
+    def _parse_type(buffer, start_pos, end_pos, variables, require_eof)
+
+    end
+
+    def _parse_method_type(buffer, start_pos, end_pos, variables, require_eof)
+
+    end
+
+    def self._parse_signature(buffer, start_pos, end_pos)
+      str = buffer.content
+
+      parser = new_parser(str, start_pos, end_pos)
+
+      signature_ptr = FFI::MemoryPointer.new(:pointer, 1)
+
+      result = Native.rbs_parse_signature parser, signature_ptr
+
+      signature = Native::Signature.new(signature_ptr.get_pointer(0))
+
+      raise RuntimeError.new("failed to parse signature") unless result
+
+      [signature.directives, signature.declarations]
+    end
+
+    def _parse_type_params(buffer, start_pos, end_pos, module_type_params)
+
+    end
+
+    def _parse_inline_leading_annotation(buffer, start_pos, end_pos, variables)
+
+    end
+
+    def _parse_inline_trailing_annotation(buffer, start_pos, end_pos, variables)
+
+    end
+  end
+end