diff --git a/Steepfile b/Steepfile
index f799db461..81d1ef930 100644
--- a/Steepfile
+++ b/Steepfile
@@ -9,7 +9,7 @@ target :lib do
     "lib/rbs/test.rb"
   )
 
-  library "set", "pathname", "json", "logger", "monitor", "tsort", "uri", 'dbm', 'pstore', 'singleton', 'shellwords', 'fileutils', 'find', 'digest'
+  library "set", "pathname", "json", "logger", "monitor", "tsort", "uri", 'dbm', 'pstore', 'singleton', 'shellwords', 'fileutils', 'find', 'digest', 'ripper'
   signature 'stdlib/yaml/0'
   signature "stdlib/strscan/0/"
   signature "stdlib/optparse/0/"
diff --git a/sig/shims/ripper.rbs b/sig/shims/ripper.rbs
deleted file mode 100644
index 6f8b1d769..000000000
--- a/sig/shims/ripper.rbs
+++ /dev/null
@@ -1,8 +0,0 @@
-class Ripper
-  def self.lex: (String src, ?String filename, ?Integer lineno, ?raise_errors: bool) -> Array[[[Integer, Integer], Symbol, String, Lexer::State]]
-
-  class Lexer
-    class State
-    end
-  end
-end
diff --git a/stdlib/ripper/0/ripper.rbs b/stdlib/ripper/0/ripper.rbs
new file mode 100644
index 000000000..091dbcfc2
--- /dev/null
+++ b/stdlib/ripper/0/ripper.rbs
@@ -0,0 +1,1650 @@
+# <!-- rdoc-file=ext/ripper/lib/ripper.rb -->
+# Ripper is a Ruby script parser.
+#
+# You can get information from the parser with event-based style. Information
+# such as abstract syntax trees or simple lexical analysis of the Ruby program.
+#
+# ## Usage
+#
+# Ripper provides an easy interface for parsing your program into a symbolic
+# expression tree (or S-expression).
+#
+# Understanding the output of the parser may come as a challenge, it's
+# recommended you use PP to format the output for legibility.
+#
+#     require 'ripper'
+#     require 'pp'
+#
+#     pp Ripper.sexp('def hello(world) "Hello, #{world}!"; end')
+#       #=> [:program,
+#            [[:def,
+#              [:@ident, "hello", [1, 4]],
+#              [:paren,
+#               [:params, [[:@ident, "world", [1, 10]]], nil, nil, nil, nil, nil, nil]],
+#              [:bodystmt,
+#               [[:string_literal,
+#                 [:string_content,
+#                  [:@tstring_content, "Hello, ", [1, 18]],
+#                  [:string_embexpr, [[:var_ref, [:@ident, "world", [1, 27]]]]],
+#                  [:@tstring_content, "!", [1, 33]]]]],
+#               nil,
+#               nil,
+#               nil]]]]
+#
+# You can see in the example above, the expression starts with `:program`.
+#
+# From here, a method definition at `:def`, followed by the method's identifier
+# `:@ident`. After the method's identifier comes the parentheses `:paren` and
+# the method parameters under `:params`.
+#
+# Next is the method body, starting at `:bodystmt` (`stmt` meaning statement),
+# which contains the full definition of the method.
+#
+# In our case, we're simply returning a String, so next we have the
+# `:string_literal` expression.
+#
+# Within our `:string_literal` you'll notice two `@tstring_content`, this is the
+# literal part for `Hello, ` and `!`. Between the two `@tstring_content`
+# statements is a `:string_embexpr`, where *embexpr* is an embedded expression.
+# Our expression consists of a local variable, or `var_ref`, with the identifier
+# (`@ident`) of `world`.
+#
+# ## Resources
+#
+# *   [Ruby
+#     Inside](http://www.rubyinside.com/using-ripper-to-see-how-ruby-is-parsing-
+#     your-code-5270.html)
+#
+#
+# ## Requirements
+#
+# *   ruby 1.9 (support CVS HEAD only)
+# *   bison 1.28 or later (Other yaccs do not work)
+#
+#
+# ## License
+#
+# Ruby License.
+#
+# *   Minero Aoki
+# *   aamine@loveruby.net
+# *   http://i.loveruby.net
+#
+class Ripper
+  # <!-- rdoc-file=ext/ripper/lib/ripper/core.rb -->
+  # This array contains name of all ripper events.
+  #
+  EVENTS: Array[Symbol]
+
+  EXPR_ARG: Integer
+
+  EXPR_ARG_ANY: Integer
+
+  EXPR_BEG: Integer
+
+  EXPR_BEG_ANY: Integer
+
+  EXPR_CLASS: Integer
+
+  EXPR_CMDARG: Integer
+
+  EXPR_DOT: Integer
+
+  EXPR_END: Integer
+
+  EXPR_ENDARG: Integer
+
+  EXPR_ENDFN: Integer
+
+  EXPR_END_ANY: Integer
+
+  EXPR_FITEM: Integer
+
+  EXPR_FNAME: Integer
+
+  EXPR_LABEL: Integer
+
+  EXPR_LABELED: Integer
+
+  EXPR_MID: Integer
+
+  EXPR_NONE: Integer
+
+  EXPR_VALUE: Integer
+
+  # <!-- rdoc-file=ext/ripper/lib/ripper/core.rb -->
+  # This array contains name of parser events.
+  #
+  PARSER_EVENTS: Array[Symbol]
+
+  PARSER_EVENT_TABLE: Hash[Symbol, Integer]
+
+  # <!-- rdoc-file=ext/ripper/lib/ripper/core.rb -->
+  # This array contains name of scanner events.
+  #
+  SCANNER_EVENTS: Array[Symbol]
+
+  SCANNER_EVENT_TABLE: Hash[Symbol, Integer]
+
+  # <!-- rdoc-file=parse.c -->
+  # version of Ripper
+  #
+  Version: String
+
+  # <!-- rdoc-file=ext/ripper/lib/ripper/filter.rb -->
+  # This class handles only scanner events, which are dispatched in the 'right'
+  # order (same with input).
+  #
+  class Filter
+    private
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - new(src, filename = '-', lineno = 1)
+    # -->
+    # Creates a new Ripper::Filter instance, passes parameters `src`, `filename`,
+    # and `lineno` to Ripper::Lexer.new
+    #
+    # The lexer is for internal use only.
+    #
+    def initialize: (File | _Gets | String src, ?String filename, ?Integer lineno) -> void
+
+    public
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - column()
+    # -->
+    # The column number of the current token. This value starts from 0. This method
+    # is valid only in event handlers.
+    #
+    def column: () -> Integer?
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - filename()
+    # -->
+    # The file name of the input.
+    #
+    def filename: () -> String
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - lineno()
+    # -->
+    # The line number of the current token. This value starts from 1. This method is
+    # valid only in event handlers.
+    #
+    def lineno: () -> Integer?
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - parse(init = nil)
+    # -->
+    # Starts the parser. `init` is a data accumulator and is passed to the next
+    # event handler (as of Enumerable#inject).
+    #
+    def parse: (?untyped init) -> untyped
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - state()
+    # -->
+    # The scanner's state of the current token. This value is the bitwise OR of zero
+    # or more of the `Ripper::EXPR_*` constants.
+    #
+    def state: () -> Ripper::Lexer::State
+
+    private
+
+    # <!--
+    #   rdoc-file=ext/ripper/lib/ripper/filter.rb
+    #   - on_default(event, token, data)
+    # -->
+    # This method is called when some event handler is undefined. `event` is
+    # :on_XXX, `token` is the scanned token, and `data` is a data accumulator.
+    #
+    # The return value of this method is passed to the next event handler (as of
+    # Enumerable#inject).
+    #
+    def on_default: (untyped event, untyped token, untyped data) -> untyped
+  end
+
+  class Lexer < Ripper
+    class Elem
+      attr_accessor event: Symbol
+
+      attr_accessor message: String?
+      attr_accessor pos: [ Integer, Integer ]
+
+      attr_accessor state: Ripper::Lexer::State
+      attr_accessor tok: String
+
+      private
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - new(pos, event, tok, state, message = nil)
+      # -->
+      #
+      def initialize: ([ Integer, Integer ] pos, Symbol event, String tok, Integer | Ripper::Lexer::State state, ?String? message) -> void
+
+      public
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - [](index)
+      # -->
+      #
+      def []: (0 | :pos) -> [ Integer, Integer ]
+            | (1 | :event) -> Symbol
+            | (2 | :tok) -> String
+            | (3 | :state) -> Ripper::Lexer::State
+            | (4 | :message) -> String?
+            | (Integer | Symbol) -> untyped
+            | (untyped) -> nil
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - to_a()
+      # -->
+      #
+      def to_a: () -> [ [ Integer, Integer ], Symbol, String, Ripper::Lexer::State, String ]
+              | () -> [ [ Integer, Integer ], Symbol, String, Ripper::Lexer::State ]
+    end
+
+    class State
+      attr_reader to_int: Integer
+      attr_reader to_s: String
+
+      private
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - new(i)
+      # -->
+      #
+      def initialize: (Integer | State i) -> void
+
+      public
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - &(i)
+      # -->
+      #
+      def &: (Integer i) -> State
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - ==(i)
+      # -->
+      #
+      def ==: (Integer | State i) -> bool
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - [](index)
+      # -->
+      #
+      def []: (0 | :to_int index) -> (Integer | State)
+            | (1 | :to_s index) -> String
+            | (untyped) -> nil
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - allbits?(i)
+      # -->
+      #
+      def allbits?: (int i) -> bool
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - anybits?(i)
+      # -->
+      #
+      def anybits?: (int i) -> bool
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - nobits?(i)
+      # -->
+      #
+      def nobits?: (int i) -> bool
+
+      alias to_i to_int
+
+      # <!--
+      #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+      #   - |(i)
+      # -->
+      #
+      def |: (Integer i) -> State
+    end
+    attr_reader errors: Array[Lexer::Elem]
+
+    alias compile_error on_error1
+    def lex: (?raise_errors: boolish) -> Array[[ [ Integer, Integer ], Symbol, String, Lexer::State ]]
+
+    alias on_CHAR _push_token
+
+    alias on___end__ _push_token
+
+    alias on_alias_error on_error2
+
+    alias on_assign_error on_error2
+
+    alias on_backref _push_token
+
+    alias on_backtick _push_token
+
+    alias on_class_name_error on_error2
+
+    alias on_comma _push_token
+
+    alias on_comment _push_token
+
+    alias on_const _push_token
+
+    alias on_cvar _push_token
+
+    alias on_embdoc _push_token
+
+    alias on_embdoc_beg _push_token
+
+    alias on_embdoc_end _push_token
+
+    alias on_embexpr_beg _push_token
+
+    alias on_embexpr_end _push_token
+
+    alias on_embvar _push_token
+
+    alias on_float _push_token
+
+    alias on_gvar _push_token
+
+    alias on_ident _push_token
+
+    alias on_ignored_nl _push_token
+
+    alias on_ignored_sp _push_token
+
+    alias on_imaginary _push_token
+
+    alias on_int _push_token
+
+    alias on_ivar _push_token
+
+    alias on_kw _push_token
+
+    alias on_label _push_token
+
+    alias on_label_end _push_token
+
+    alias on_lbrace _push_token
+
+    alias on_lbracket _push_token
+
+    alias on_lparen _push_token
+
+    alias on_nl _push_token
+
+    alias on_op _push_token
+
+    alias on_param_error on_error2
+
+    alias on_parse_error on_error1
+
+    alias on_period _push_token
+
+    alias on_qsymbols_beg _push_token
+
+    alias on_qwords_beg _push_token
+
+    alias on_rational _push_token
+
+    alias on_rbrace _push_token
+
+    alias on_rbracket _push_token
+
+    alias on_regexp_beg _push_token
+
+    alias on_regexp_end _push_token
+
+    alias on_rparen _push_token
+
+    alias on_semicolon _push_token
+
+    alias on_sp _push_token
+
+    alias on_symbeg _push_token
+
+    alias on_symbols_beg _push_token
+
+    alias on_tlambda _push_token
+
+    alias on_tlambeg _push_token
+
+    alias on_tstring_beg _push_token
+
+    alias on_tstring_content _push_token
+
+    alias on_tstring_end _push_token
+
+    alias on_words_beg _push_token
+
+    alias on_words_sep _push_token
+    def parse: (?raise_errors: boolish) -> Array[Lexer::Elem]
+
+    def scan: (?raise_errors: boolish) -> Array[Lexer::Elem]
+
+    def tokenize: (?raise_errors: boolish) -> Array[String]
+
+    private
+
+    def _push_token: (untyped tok) -> Lexer::Elem
+
+    def on_error1: (untyped mesg) -> Array[Lexer::Elem]
+
+    def on_error2: (untyped mesg, untyped elem) -> Array[Lexer::Elem]
+
+    def on_heredoc_beg: (untyped tok) -> untyped
+
+    def on_heredoc_dedent: (untyped v, untyped w) -> untyped
+
+    def on_heredoc_end: (untyped tok) -> untyped
+  end
+
+  class SexpBuilder < Ripper
+    attr_reader error: untyped
+
+    alias compile_error on_error
+    def on_BEGIN: (*untyped args) -> untyped
+
+    def on_CHAR: (untyped tok) -> untyped
+
+    def on_END: (*untyped args) -> untyped
+
+    def on___end__: (untyped tok) -> untyped
+
+    def on_alias: (*untyped args) -> untyped
+
+    def on_alias_error: (*untyped args) -> untyped
+
+    def on_aref: (*untyped args) -> untyped
+
+    def on_aref_field: (*untyped args) -> untyped
+
+    def on_arg_ambiguous: (*untyped args) -> untyped
+
+    def on_arg_paren: (*untyped args) -> untyped
+
+    def on_args_add: (*untyped args) -> untyped
+
+    def on_args_add_block: (*untyped args) -> untyped
+
+    def on_args_add_star: (*untyped args) -> untyped
+
+    def on_args_forward: (*untyped args) -> untyped
+
+    def on_args_new: (*untyped args) -> untyped
+
+    def on_array: (*untyped args) -> untyped
+
+    def on_aryptn: (*untyped args) -> untyped
+
+    def on_assign: (*untyped args) -> untyped
+
+    def on_assign_error: (*untyped args) -> untyped
+
+    def on_assoc_new: (*untyped args) -> untyped
+
+    def on_assoc_splat: (*untyped args) -> untyped
+
+    def on_assoclist_from_args: (*untyped args) -> untyped
+
+    def on_backref: (untyped tok) -> untyped
+
+    def on_backtick: (untyped tok) -> untyped
+
+    def on_bare_assoc_hash: (*untyped args) -> untyped
+
+    def on_begin: (*untyped args) -> untyped
+
+    def on_binary: (*untyped args) -> untyped
+
+    def on_block_var: (*untyped args) -> untyped
+
+    def on_blockarg: (*untyped args) -> untyped
+
+    def on_bodystmt: (*untyped args) -> untyped
+
+    def on_brace_block: (*untyped args) -> untyped
+
+    def on_break: (*untyped args) -> untyped
+
+    def on_call: (*untyped args) -> untyped
+
+    def on_case: (*untyped args) -> untyped
+
+    def on_class: (*untyped args) -> untyped
+
+    def on_class_name_error: (*untyped args) -> untyped
+
+    def on_comma: (untyped tok) -> untyped
+
+    def on_command: (*untyped args) -> untyped
+
+    def on_command_call: (*untyped args) -> untyped
+
+    def on_comment: (untyped tok) -> untyped
+
+    def on_const: (untyped tok) -> untyped
+
+    def on_const_path_field: (*untyped args) -> untyped
+
+    def on_const_path_ref: (*untyped args) -> untyped
+
+    def on_const_ref: (*untyped args) -> untyped
+
+    def on_cvar: (untyped tok) -> untyped
+
+    def on_def: (*untyped args) -> untyped
+
+    def on_defined: (*untyped args) -> untyped
+
+    def on_defs: (*untyped args) -> untyped
+
+    def on_do_block: (*untyped args) -> untyped
+
+    def on_dot2: (*untyped args) -> untyped
+
+    def on_dot3: (*untyped args) -> untyped
+
+    def on_dyna_symbol: (*untyped args) -> untyped
+
+    def on_else: (*untyped args) -> untyped
+
+    def on_elsif: (*untyped args) -> untyped
+
+    def on_embdoc: (untyped tok) -> untyped
+
+    def on_embdoc_beg: (untyped tok) -> untyped
+
+    def on_embdoc_end: (untyped tok) -> untyped
+
+    def on_embexpr_beg: (untyped tok) -> untyped
+
+    def on_embexpr_end: (untyped tok) -> untyped
+
+    def on_embvar: (untyped tok) -> untyped
+
+    def on_ensure: (*untyped args) -> untyped
+
+    def on_excessed_comma: (*untyped args) -> untyped
+
+    def on_fcall: (*untyped args) -> untyped
+
+    def on_field: (*untyped args) -> untyped
+
+    def on_float: (untyped tok) -> untyped
+
+    def on_fndptn: (*untyped args) -> untyped
+
+    def on_for: (*untyped args) -> untyped
+
+    def on_gvar: (untyped tok) -> untyped
+
+    def on_hash: (*untyped args) -> untyped
+
+    def on_heredoc_beg: (untyped tok) -> untyped
+
+    def on_heredoc_end: (untyped tok) -> untyped
+
+    def on_hshptn: (*untyped args) -> untyped
+
+    def on_ident: (untyped tok) -> untyped
+
+    def on_if: (*untyped args) -> untyped
+
+    def on_if_mod: (*untyped args) -> untyped
+
+    def on_ifop: (*untyped args) -> untyped
+
+    def on_ignored_nl: (untyped tok) -> untyped
+
+    def on_ignored_sp: (untyped tok) -> untyped
+
+    def on_imaginary: (untyped tok) -> untyped
+
+    def on_in: (*untyped args) -> untyped
+
+    def on_int: (untyped tok) -> untyped
+
+    def on_ivar: (untyped tok) -> untyped
+
+    def on_kw: (untyped tok) -> untyped
+
+    def on_kwrest_param: (*untyped args) -> untyped
+
+    def on_label: (untyped tok) -> untyped
+
+    def on_label_end: (untyped tok) -> untyped
+
+    def on_lambda: (*untyped args) -> untyped
+
+    def on_lbrace: (untyped tok) -> untyped
+
+    def on_lbracket: (untyped tok) -> untyped
+
+    def on_lparen: (untyped tok) -> untyped
+
+    def on_magic_comment: (*untyped args) -> untyped
+
+    def on_massign: (*untyped args) -> untyped
+
+    def on_method_add_arg: (*untyped args) -> untyped
+
+    def on_method_add_block: (*untyped args) -> untyped
+
+    def on_mlhs_add: (*untyped args) -> untyped
+
+    def on_mlhs_add_post: (*untyped args) -> untyped
+
+    def on_mlhs_add_star: (*untyped args) -> untyped
+
+    def on_mlhs_new: (*untyped args) -> untyped
+
+    def on_mlhs_paren: (*untyped args) -> untyped
+
+    def on_module: (*untyped args) -> untyped
+
+    def on_mrhs_add: (*untyped args) -> untyped
+
+    def on_mrhs_add_star: (*untyped args) -> untyped
+
+    def on_mrhs_new: (*untyped args) -> untyped
+
+    def on_mrhs_new_from_args: (*untyped args) -> untyped
+
+    def on_next: (*untyped args) -> untyped
+
+    def on_nl: (untyped tok) -> untyped
+
+    def on_nokw_param: (*untyped args) -> untyped
+
+    def on_op: (untyped tok) -> untyped
+
+    def on_opassign: (*untyped args) -> untyped
+
+    def on_operator_ambiguous: (*untyped args) -> untyped
+
+    def on_param_error: (*untyped args) -> untyped
+
+    def on_params: (*untyped args) -> untyped
+
+    def on_paren: (*untyped args) -> untyped
+
+    alias on_parse_error on_error
+    def on_period: (untyped tok) -> untyped
+
+    def on_program: (*untyped args) -> untyped
+
+    def on_qsymbols_add: (*untyped args) -> untyped
+
+    def on_qsymbols_beg: (untyped tok) -> untyped
+
+    def on_qsymbols_new: (*untyped args) -> untyped
+
+    def on_qwords_add: (*untyped args) -> untyped
+
+    def on_qwords_beg: (untyped tok) -> untyped
+
+    def on_qwords_new: (*untyped args) -> untyped
+
+    def on_rational: (untyped tok) -> untyped
+
+    def on_rbrace: (untyped tok) -> untyped
+
+    def on_rbracket: (untyped tok) -> untyped
+
+    def on_redo: (*untyped args) -> untyped
+
+    def on_regexp_add: (*untyped args) -> untyped
+
+    def on_regexp_beg: (untyped tok) -> untyped
+
+    def on_regexp_end: (untyped tok) -> untyped
+
+    def on_regexp_literal: (*untyped args) -> untyped
+
+    def on_regexp_new: (*untyped args) -> untyped
+
+    def on_rescue: (*untyped args) -> untyped
+
+    def on_rescue_mod: (*untyped args) -> untyped
+
+    def on_rest_param: (*untyped args) -> untyped
+
+    def on_retry: (*untyped args) -> untyped
+
+    def on_return: (*untyped args) -> untyped
+
+    def on_return0: (*untyped args) -> untyped
+
+    def on_rparen: (untyped tok) -> untyped
+
+    def on_sclass: (*untyped args) -> untyped
+
+    def on_semicolon: (untyped tok) -> untyped
+
+    def on_sp: (untyped tok) -> untyped
+
+    def on_stmts_add: (*untyped args) -> untyped
+
+    def on_stmts_new: (*untyped args) -> untyped
+
+    def on_string_add: (*untyped args) -> untyped
+
+    def on_string_concat: (*untyped args) -> untyped
+
+    def on_string_content: (*untyped args) -> untyped
+
+    def on_string_dvar: (*untyped args) -> untyped
+
+    def on_string_embexpr: (*untyped args) -> untyped
+
+    def on_string_literal: (*untyped args) -> untyped
+
+    def on_super: (*untyped args) -> untyped
+
+    def on_symbeg: (untyped tok) -> untyped
+
+    def on_symbol: (*untyped args) -> untyped
+
+    def on_symbol_literal: (*untyped args) -> untyped
+
+    def on_symbols_add: (*untyped args) -> untyped
+
+    def on_symbols_beg: (untyped tok) -> untyped
+
+    def on_symbols_new: (*untyped args) -> untyped
+
+    def on_tlambda: (untyped tok) -> untyped
+
+    def on_tlambeg: (untyped tok) -> untyped
+
+    def on_top_const_field: (*untyped args) -> untyped
+
+    def on_top_const_ref: (*untyped args) -> untyped
+
+    def on_tstring_beg: (untyped tok) -> untyped
+
+    def on_tstring_content: (untyped tok) -> untyped
+
+    def on_tstring_end: (untyped tok) -> untyped
+
+    def on_unary: (*untyped args) -> untyped
+
+    def on_undef: (*untyped args) -> untyped
+
+    def on_unless: (*untyped args) -> untyped
+
+    def on_unless_mod: (*untyped args) -> untyped
+
+    def on_until: (*untyped args) -> untyped
+
+    def on_until_mod: (*untyped args) -> untyped
+
+    def on_var_alias: (*untyped args) -> untyped
+
+    def on_var_field: (*untyped args) -> untyped
+
+    def on_var_ref: (*untyped args) -> untyped
+
+    def on_vcall: (*untyped args) -> untyped
+
+    def on_void_stmt: (*untyped args) -> untyped
+
+    def on_when: (*untyped args) -> untyped
+
+    def on_while: (*untyped args) -> untyped
+
+    def on_while_mod: (*untyped args) -> untyped
+
+    def on_word_add: (*untyped args) -> untyped
+
+    def on_word_new: (*untyped args) -> untyped
+
+    def on_words_add: (*untyped args) -> untyped
+
+    def on_words_beg: (untyped tok) -> untyped
+
+    def on_words_new: (*untyped args) -> untyped
+
+    def on_words_sep: (untyped tok) -> untyped
+
+    def on_xstring_add: (*untyped args) -> untyped
+
+    def on_xstring_literal: (*untyped args) -> untyped
+
+    def on_xstring_new: (*untyped args) -> untyped
+
+    def on_yield: (*untyped args) -> untyped
+
+    def on_yield0: (*untyped args) -> untyped
+
+    def on_zsuper: (*untyped args) -> untyped
+
+    private
+
+    def dedent_element: (untyped e, untyped width) -> untyped
+
+    def on_error: (untyped mesg) -> untyped
+
+    def on_heredoc_dedent: (untyped val, untyped width) -> untyped
+  end
+
+  class SexpBuilderPP < Ripper::SexpBuilder
+    alias on_args_add _dispatch_event_push
+
+    alias on_args_new _dispatch_event_new
+
+    alias on_mlhs_add _dispatch_event_push
+
+    alias on_mlhs_new _dispatch_event_new
+
+    alias on_mrhs_add _dispatch_event_push
+
+    alias on_mrhs_new _dispatch_event_new
+
+    alias on_qsymbols_add _dispatch_event_push
+
+    alias on_qsymbols_new _dispatch_event_new
+
+    alias on_qwords_add _dispatch_event_push
+
+    alias on_qwords_new _dispatch_event_new
+
+    alias on_regexp_add _dispatch_event_push
+
+    alias on_regexp_new _dispatch_event_new
+
+    alias on_stmts_add _dispatch_event_push
+
+    alias on_stmts_new _dispatch_event_new
+
+    alias on_string_add _dispatch_event_push
+
+    alias on_symbols_add _dispatch_event_push
+
+    alias on_symbols_new _dispatch_event_new
+
+    alias on_word_add _dispatch_event_push
+
+    alias on_word_new _dispatch_event_new
+
+    alias on_words_add _dispatch_event_push
+
+    alias on_words_new _dispatch_event_new
+
+    alias on_xstring_add _dispatch_event_push
+
+    alias on_xstring_new _dispatch_event_new
+
+    private
+
+    def _dispatch_event_new: () -> untyped
+
+    def _dispatch_event_push: (untyped list, untyped item) -> untyped
+
+    def on_heredoc_dedent: (untyped val, untyped width) -> untyped
+
+    def on_mlhs_add_post: (untyped list, untyped post) -> untyped
+
+    def on_mlhs_add_star: (untyped list, untyped star) -> untyped
+
+    def on_mlhs_paren: (untyped list) -> untyped
+  end
+
+  class TokenPattern
+    MAP: Hash[String, String]
+
+    class CompileError < Error
+    end
+    class Error < StandardError
+    end
+
+    class MatchData
+      private
+
+      def initialize: (untyped tokens, untyped match) -> void
+
+      public
+
+      def string: (?untyped n) -> untyped
+
+      private
+
+      def match: (?untyped n) -> untyped
+    end
+    class MatchError < Error
+    end
+    alias self.compile self.new
+
+    private
+
+    def initialize: (untyped pattern) -> void
+
+    public
+
+    def match: (untyped str) -> untyped
+
+    def match_list: (untyped tokens) -> untyped
+
+    private
+
+    def compile: (untyped pattern) -> untyped
+
+    def map_token: (untyped tok) -> untyped
+
+    def map_tokens: (untyped tokens) -> untyped
+  end
+  interface _Gets
+    def gets: (?String sep, ?Integer limit) -> String?
+  end
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - Ripper.dedent_string(input, width)   -> Integer
+  # -->
+  # USE OF RIPPER LIBRARY ONLY.
+  #
+  # Strips up to `width` leading whitespaces from `input`, and returns the
+  # stripped column width.
+  #
+  def self.dedent_string: (String input, int width) -> Integer
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+  #   - lex(src, filename = '-', lineno = 1, **kw)
+  # -->
+  # Tokenizes the Ruby program and returns an array of an array, which is
+  # formatted like `[[lineno, column], type, token, state]`. The `filename`
+  # argument is mostly ignored. By default, this method does not handle syntax
+  # errors in `src`, use the `raise_errors` keyword to raise a SyntaxError for an
+  # error in `src`.
+  #
+  #     require 'ripper'
+  #     require 'pp'
+  #
+  #     pp Ripper.lex("def m(a) nil end")
+  #     #=> [[[1,  0], :on_kw,     "def", FNAME    ],
+  #          [[1,  3], :on_sp,     " ",   FNAME    ],
+  #          [[1,  4], :on_ident,  "m",   ENDFN    ],
+  #          [[1,  5], :on_lparen, "(",   BEG|LABEL],
+  #          [[1,  6], :on_ident,  "a",   ARG      ],
+  #          [[1,  7], :on_rparen, ")",   ENDFN    ],
+  #          [[1,  8], :on_sp,     " ",   BEG      ],
+  #          [[1,  9], :on_kw,     "nil", END      ],
+  #          [[1, 12], :on_sp,     " ",   END      ],
+  #          [[1, 13], :on_kw,     "end", END      ]]
+  #
+  def self.lex: (String src, ?String filename, ?Integer lineno, ?raise_errors: boolish) -> Array[[ [ Integer, Integer ], Symbol, String, Lexer::State ]]
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - Ripper.lex_state_name(integer)   -> string
+  # -->
+  # Returns a string representation of lex_state.
+  #
+  def self.lex_state_name: (int) -> String
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/core.rb
+  #   - parse(src, filename = '(ripper)', lineno = 1)
+  # -->
+  # Parses the given Ruby program read from `src`. `src` must be a String or an IO
+  # or a object with a #gets method.
+  #
+  def self.parse: (File | _Gets | String src, ?String filename, ?Integer lineno) -> nil
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/sexp.rb
+  #   - sexp(src, filename = '-', lineno = 1, raise_errors: false)
+  # -->
+  # EXPERIMENTAL
+  # :   Parses `src` and create S-exp tree. Returns more readable tree rather than
+  #     Ripper.sexp_raw. This method is mainly for developer use. The `filename`
+  #     argument is mostly ignored. By default, this method does not handle syntax
+  #     errors in `src`, returning `nil` in such cases. Use the `raise_errors`
+  #     keyword to raise a SyntaxError for an error in `src`.
+  #
+  #         require 'ripper'
+  #         require 'pp'
+  #
+  #         pp Ripper.sexp("def m(a) nil end")
+  #           #=> [:program,
+  #                [[:def,
+  #                 [:@ident, "m", [1, 4]],
+  #                 [:paren, [:params, [[:@ident, "a", [1, 6]]], nil, nil, nil, nil, nil, nil]],
+  #                 [:bodystmt, [[:var_ref, [:@kw, "nil", [1, 9]]]], nil, nil, nil]]]]
+  #
+  def self.sexp: (File | _Gets | String src, ?String filename, ?Integer lineno, ?raise_errors: boolish) -> Array[untyped]
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/sexp.rb
+  #   - sexp_raw(src, filename = '-', lineno = 1, raise_errors: false)
+  # -->
+  # EXPERIMENTAL
+  # :   Parses `src` and create S-exp tree. This method is mainly for developer
+  #     use. The `filename` argument is mostly ignored. By default, this method
+  #     does not handle syntax errors in `src`, returning `nil` in such cases. Use
+  #     the `raise_errors` keyword to raise a SyntaxError for an error in `src`.
+  #
+  #         require 'ripper'
+  #         require 'pp'
+  #
+  #         pp Ripper.sexp_raw("def m(a) nil end")
+  #           #=> [:program,
+  #                [:stmts_add,
+  #                 [:stmts_new],
+  #                 [:def,
+  #                  [:@ident, "m", [1, 4]],
+  #                  [:paren, [:params, [[:@ident, "a", [1, 6]]], nil, nil, nil]],
+  #                  [:bodystmt,
+  #                   [:stmts_add, [:stmts_new], [:var_ref, [:@kw, "nil", [1, 9]]]],
+  #                   nil,
+  #                   nil,
+  #                   nil]]]]
+  #
+  def self.sexp_raw: (File | _Gets | String src, ?String filename, ?Integer lineno, ?raise_errors: boolish) -> Array[untyped]
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+  #   - slice(src, pattern, n = 0)
+  # -->
+  # EXPERIMENTAL
+  # :   Parses `src` and return a string which was matched to `pattern`. `pattern`
+  #     should be described as Regexp.
+  #
+  #         require 'ripper'
+  #
+  #         p Ripper.slice('def m(a) nil end', 'ident')                   #=> "m"
+  #         p Ripper.slice('def m(a) nil end', '[ident lparen rparen]+')  #=> "m(a)"
+  #         p Ripper.slice("<<EOS\nstring\nEOS",
+  #                        'heredoc_beg nl $(tstring_content*) heredoc_end', 1)
+  #             #=> "string\n"
+  #
+  def self.slice: (String src, String pattern, ?Integer n) -> String?
+
+  def self.token_match: (String src, String pattern) -> Ripper::TokenPattern::MatchData?
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/lexer.rb
+  #   - tokenize(src, filename = '-', lineno = 1, **kw)
+  # -->
+  # Tokenizes the Ruby program and returns an array of strings. The `filename` and
+  # `lineno` arguments are mostly ignored, since the return value is just the
+  # tokenized input. By default, this method does not handle syntax errors in
+  # `src`, use the `raise_errors` keyword to raise a SyntaxError for an error in
+  # `src`.
+  #
+  #     p Ripper.tokenize("def m(a) nil end")
+  #        # => ["def", " ", "m", "(", "a", ")", " ", "nil", " ", "end"]
+  #
+  def self.tokenize: (File | _Gets | String src, ?String filename, ?Integer lineno, ?raise_errors: boolish) -> Array[String]
+
+  private
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - Ripper.new(src, filename="(ripper)", lineno=1) -> ripper
+  # -->
+  # Create a new Ripper object. *src* must be a String, an IO, or an Object which
+  # has #gets method.
+  #
+  # This method does not starts parsing. See also Ripper#parse and Ripper.parse.
+  #
+  def initialize: (File | _Gets | String src, ?String filename, ?Integer lineno) -> void
+
+  public
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.column   -> Integer
+  # -->
+  # Return column number of current parsing line. This number starts from 0.
+  #
+  def column: () -> Integer?
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.debug_output   -> obj
+  # -->
+  # Get debug output.
+  #
+  def debug_output: () -> untyped
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.debug_output = obj
+  # -->
+  # Set debug output.
+  #
+  def debug_output=: (untyped) -> untyped
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.encoding   -> encoding
+  # -->
+  # Return encoding of the source.
+  #
+  def encoding: () -> Encoding
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.end_seen?   -> Boolean
+  # -->
+  # Return true if parsed source ended by +_*END*_+.
+  #
+  def end_seen?: () -> bool
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.error?   -> Boolean
+  # -->
+  # Return true if parsed source has errors.
+  #
+  def error?: () -> bool
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.filename   -> String
+  # -->
+  # Return current parsing filename.
+  #
+  def filename: () -> String
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.lineno   -> Integer
+  # -->
+  # Return line number of current parsing line. This number starts from 1.
+  #
+  def lineno: () -> Integer?
+
+  alias on_BEGIN _dispatch_1
+
+  alias on_CHAR _dispatch_1
+
+  alias on_END _dispatch_1
+
+  alias on___end__ _dispatch_1
+
+  alias on_alias _dispatch_2
+
+  alias on_alias_error _dispatch_2
+
+  alias on_aref _dispatch_2
+
+  alias on_aref_field _dispatch_2
+
+  alias on_arg_ambiguous _dispatch_1
+
+  alias on_arg_paren _dispatch_1
+
+  alias on_args_add _dispatch_2
+
+  alias on_args_add_block _dispatch_2
+
+  alias on_args_add_star _dispatch_2
+
+  alias on_args_forward _dispatch_0
+
+  alias on_args_new _dispatch_0
+
+  alias on_array _dispatch_1
+
+  alias on_aryptn _dispatch_4
+
+  alias on_assign _dispatch_2
+
+  alias on_assign_error _dispatch_2
+
+  alias on_assoc_new _dispatch_2
+
+  alias on_assoc_splat _dispatch_1
+
+  alias on_assoclist_from_args _dispatch_1
+
+  alias on_backref _dispatch_1
+
+  alias on_backtick _dispatch_1
+
+  alias on_bare_assoc_hash _dispatch_1
+
+  alias on_begin _dispatch_1
+
+  alias on_binary _dispatch_3
+
+  alias on_block_var _dispatch_2
+
+  alias on_blockarg _dispatch_1
+
+  alias on_bodystmt _dispatch_4
+
+  alias on_brace_block _dispatch_2
+
+  alias on_break _dispatch_1
+
+  alias on_call _dispatch_3
+
+  alias on_case _dispatch_2
+
+  alias on_class _dispatch_3
+
+  alias on_class_name_error _dispatch_2
+
+  alias on_comma _dispatch_1
+
+  alias on_command _dispatch_2
+
+  alias on_command_call _dispatch_4
+
+  alias on_comment _dispatch_1
+
+  alias on_const _dispatch_1
+
+  alias on_const_path_field _dispatch_2
+
+  alias on_const_path_ref _dispatch_2
+
+  alias on_const_ref _dispatch_1
+
+  alias on_cvar _dispatch_1
+
+  alias on_def _dispatch_3
+
+  alias on_defined _dispatch_1
+
+  alias on_defs _dispatch_5
+
+  alias on_do_block _dispatch_2
+
+  alias on_dot2 _dispatch_2
+
+  alias on_dot3 _dispatch_2
+
+  alias on_dyna_symbol _dispatch_1
+
+  alias on_else _dispatch_1
+
+  alias on_elsif _dispatch_3
+
+  alias on_embdoc _dispatch_1
+
+  alias on_embdoc_beg _dispatch_1
+
+  alias on_embdoc_end _dispatch_1
+
+  alias on_embexpr_beg _dispatch_1
+
+  alias on_embexpr_end _dispatch_1
+
+  alias on_embvar _dispatch_1
+
+  alias on_ensure _dispatch_1
+
+  alias on_excessed_comma _dispatch_0
+
+  alias on_fcall _dispatch_1
+
+  alias on_field _dispatch_3
+
+  alias on_float _dispatch_1
+
+  alias on_fndptn _dispatch_4
+
+  alias on_for _dispatch_3
+
+  alias on_gvar _dispatch_1
+
+  alias on_hash _dispatch_1
+
+  alias on_heredoc_beg _dispatch_1
+
+  alias on_heredoc_dedent _dispatch_2
+
+  alias on_heredoc_end _dispatch_1
+
+  alias on_hshptn _dispatch_3
+
+  alias on_ident _dispatch_1
+
+  alias on_if _dispatch_3
+
+  alias on_if_mod _dispatch_2
+
+  alias on_ifop _dispatch_3
+
+  alias on_ignored_nl _dispatch_1
+
+  alias on_imaginary _dispatch_1
+
+  alias on_in _dispatch_3
+
+  alias on_int _dispatch_1
+
+  alias on_ivar _dispatch_1
+
+  alias on_kw _dispatch_1
+
+  alias on_kwrest_param _dispatch_1
+
+  alias on_label _dispatch_1
+
+  alias on_label_end _dispatch_1
+
+  alias on_lambda _dispatch_2
+
+  alias on_lbrace _dispatch_1
+
+  alias on_lbracket _dispatch_1
+
+  alias on_lparen _dispatch_1
+
+  alias on_magic_comment _dispatch_2
+
+  alias on_massign _dispatch_2
+
+  alias on_method_add_arg _dispatch_2
+
+  alias on_method_add_block _dispatch_2
+
+  alias on_mlhs_add _dispatch_2
+
+  alias on_mlhs_add_post _dispatch_2
+
+  alias on_mlhs_add_star _dispatch_2
+
+  alias on_mlhs_new _dispatch_0
+
+  alias on_mlhs_paren _dispatch_1
+
+  alias on_module _dispatch_2
+
+  alias on_mrhs_add _dispatch_2
+
+  alias on_mrhs_add_star _dispatch_2
+
+  alias on_mrhs_new _dispatch_0
+
+  alias on_mrhs_new_from_args _dispatch_1
+
+  alias on_next _dispatch_1
+
+  alias on_nl _dispatch_1
+
+  alias on_nokw_param _dispatch_1
+
+  alias on_op _dispatch_1
+
+  alias on_opassign _dispatch_3
+
+  alias on_operator_ambiguous _dispatch_2
+
+  alias on_param_error _dispatch_2
+
+  alias on_params _dispatch_7
+
+  alias on_paren _dispatch_1
+
+  alias on_parse_error _dispatch_1
+
+  alias on_period _dispatch_1
+
+  alias on_program _dispatch_1
+
+  alias on_qsymbols_add _dispatch_2
+
+  alias on_qsymbols_beg _dispatch_1
+
+  alias on_qsymbols_new _dispatch_0
+
+  alias on_qwords_add _dispatch_2
+
+  alias on_qwords_beg _dispatch_1
+
+  alias on_qwords_new _dispatch_0
+
+  alias on_rational _dispatch_1
+
+  alias on_rbrace _dispatch_1
+
+  alias on_rbracket _dispatch_1
+
+  alias on_redo _dispatch_0
+
+  alias on_regexp_add _dispatch_2
+
+  alias on_regexp_beg _dispatch_1
+
+  alias on_regexp_end _dispatch_1
+
+  alias on_regexp_literal _dispatch_2
+
+  alias on_regexp_new _dispatch_0
+
+  alias on_rescue _dispatch_4
+
+  alias on_rescue_mod _dispatch_2
+
+  alias on_rest_param _dispatch_1
+
+  alias on_retry _dispatch_0
+
+  alias on_return _dispatch_1
+
+  alias on_return0 _dispatch_0
+
+  alias on_rparen _dispatch_1
+
+  alias on_sclass _dispatch_2
+
+  alias on_semicolon _dispatch_1
+
+  alias on_sp _dispatch_1
+
+  alias on_stmts_add _dispatch_2
+
+  alias on_stmts_new _dispatch_0
+
+  alias on_string_add _dispatch_2
+
+  alias on_string_concat _dispatch_2
+
+  alias on_string_content _dispatch_0
+
+  alias on_string_dvar _dispatch_1
+
+  alias on_string_embexpr _dispatch_1
+
+  alias on_string_literal _dispatch_1
+
+  alias on_super _dispatch_1
+
+  alias on_symbeg _dispatch_1
+
+  alias on_symbol _dispatch_1
+
+  alias on_symbol_literal _dispatch_1
+
+  alias on_symbols_add _dispatch_2
+
+  alias on_symbols_beg _dispatch_1
+
+  alias on_symbols_new _dispatch_0
+
+  alias on_tlambda _dispatch_1
+
+  alias on_tlambeg _dispatch_1
+
+  alias on_top_const_field _dispatch_1
+
+  alias on_top_const_ref _dispatch_1
+
+  alias on_tstring_beg _dispatch_1
+
+  alias on_tstring_content _dispatch_1
+
+  alias on_tstring_end _dispatch_1
+
+  alias on_unary _dispatch_2
+
+  alias on_undef _dispatch_1
+
+  alias on_unless _dispatch_3
+
+  alias on_unless_mod _dispatch_2
+
+  alias on_until _dispatch_2
+
+  alias on_until_mod _dispatch_2
+
+  alias on_var_alias _dispatch_2
+
+  alias on_var_field _dispatch_1
+
+  alias on_var_ref _dispatch_1
+
+  alias on_vcall _dispatch_1
+
+  alias on_void_stmt _dispatch_0
+
+  alias on_when _dispatch_3
+
+  alias on_while _dispatch_2
+
+  alias on_while_mod _dispatch_2
+
+  alias on_word_add _dispatch_2
+
+  alias on_word_new _dispatch_0
+
+  alias on_words_add _dispatch_2
+
+  alias on_words_beg _dispatch_1
+
+  alias on_words_new _dispatch_0
+
+  alias on_words_sep _dispatch_1
+
+  alias on_xstring_add _dispatch_2
+
+  alias on_xstring_literal _dispatch_1
+
+  alias on_xstring_new _dispatch_0
+
+  alias on_yield _dispatch_1
+
+  alias on_yield0 _dispatch_0
+
+  alias on_zsuper _dispatch_0
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.parse
+  # -->
+  # Start parsing and returns the value of the root action.
+  #
+  def parse: () -> nil
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.state   -> Integer
+  # -->
+  # Return scanner state of current token.
+  #
+  def state: () -> Integer?
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.token   -> String
+  # -->
+  # Return the current token string.
+  #
+  def token: () -> String?
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.yydebug   -> true or false
+  # -->
+  # Get yydebug.
+  #
+  def yydebug: () -> bool
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - ripper.yydebug = flag
+  # -->
+  # Set yydebug.
+  #
+  def yydebug=: (bool) -> bool
+
+  private
+
+  def _dispatch_0: () -> void
+
+  def _dispatch_1: (untyped a) -> void
+
+  def _dispatch_2: (untyped a, untyped b) -> void
+
+  def _dispatch_3: (untyped a, untyped b, untyped c) -> void
+
+  def _dispatch_4: (untyped a, untyped b, untyped c, untyped d) -> void
+
+  def _dispatch_5: (untyped a, untyped b, untyped c, untyped d, untyped e) -> void
+
+  def _dispatch_6: (untyped a, untyped b, untyped c, untyped d, untyped e, untyped f) -> void
+
+  def _dispatch_7: (untyped a, untyped b, untyped c, untyped d, untyped e, untyped f, untyped g) -> void
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/core.rb
+  #   - compile_error(msg)
+  # -->
+  # This method is called when the parser found syntax error.
+  #
+  def compile_error: (untyped msg) -> untyped
+
+  # <!--
+  #   rdoc-file=parse.c
+  #   - Ripper.dedent_string(input, width)   -> Integer
+  # -->
+  # USE OF RIPPER LIBRARY ONLY.
+  #
+  # Strips up to `width` leading whitespaces from `input`, and returns the
+  # stripped column width.
+  #
+  def dedent_string: (String input, Integer width) -> Integer
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/core.rb
+  #   - warn(fmt, *args)
+  # -->
+  # This method is called when weak warning is produced by the parser. `fmt` and
+  # `args` is printf style.
+  #
+  def warn: (untyped fmt, *untyped args) -> untyped
+
+  # <!--
+  #   rdoc-file=ext/ripper/lib/ripper/core.rb
+  #   - warning(fmt, *args)
+  # -->
+  # This method is called when strong warning is produced by the parser. `fmt` and
+  # `args` is printf style.
+  #
+  def warning: (untyped fmt, *untyped args) -> untyped
+end
diff --git a/test/stdlib/Ripper_test.rb b/test/stdlib/Ripper_test.rb
new file mode 100644
index 000000000..e5d4c1b6c
--- /dev/null
+++ b/test/stdlib/Ripper_test.rb
@@ -0,0 +1,234 @@
+require_relative "test_helper"
+
+class RipperSingletonTest < Test::Unit::TestCase
+  include TypeAssertions
+
+  library "ripper"
+  testing "singleton(::Ripper)"
+
+  def test_new
+    assert_send_type "(::File | ::Ripper::_Gets | ::String src, ?::String filename, ?::Integer lineno) -> ::Ripper",
+                     Ripper, :new, "def a; end"
+  end
+
+  def test_dedent_string
+    assert_send_type "(::String input, ::int width) -> ::Integer",
+                     Ripper, :dedent_string, "", 0
+  end
+
+  def test_lex
+    assert_send_type "(::String src, ?::String filename, ?::Integer lineno, ?raise_errors: ::boolish) -> ::Array[[ [ ::Integer, ::Integer ], ::Symbol, ::String, ::Ripper::Lexer::State ]]",
+                     Ripper, :lex, "def a; end"
+  end
+
+  def test_lex_state_name
+    assert_send_type "(::int) -> ::String",
+                     Ripper, :lex_state_name, 1
+  end
+
+  def test_parse
+    assert_send_type "(::File | ::Ripper::_Gets | ::String src, ?::String filename, ?::Integer lineno) -> nil",
+                     Ripper, :parse, "def a; end"
+  end
+
+  def test_sexp
+    assert_send_type "(::File | ::Ripper::_Gets | ::String src, ?::String filename, ?::Integer lineno, ?raise_errors: ::boolish) -> ::Array[untyped]",
+                     Ripper, :sexp, "def a; end"
+  end
+
+  def test_sexp_raw
+    assert_send_type "(::File | ::Ripper::_Gets | ::String src, ?::String filename, ?::Integer lineno, ?raise_errors: ::boolish) -> ::Array[untyped]",
+                     Ripper, :sexp_raw, "def a; end"
+  end
+
+  def test_slice
+    assert_send_type "(::String src, ::String pattern, ?::Integer n) -> ::String?",
+                     Ripper, :slice, "def a; end", ""
+  end
+
+  def test_token_match
+    assert_send_type "(::String src, ::String pattern) -> ::Ripper::TokenPattern::MatchData?",
+                     Ripper, :token_match, "def a; end", ""
+  end
+
+  def test_tokenize
+    assert_send_type "(::File | ::Ripper::_Gets | ::String src, ?::String filename, ?::Integer lineno, ?raise_errors: ::boolish) -> ::Array[::String]",
+                     Ripper, :tokenize, "def a; end"
+  end
+end
+
+class RipperTest < Test::Unit::TestCase
+  include TypeAssertions
+
+  library "ripper"
+  testing "::Ripper"
+
+  def test_warn
+    assert_send_type "(untyped fmt, *untyped args) -> untyped",
+                     Ripper.new("def a; end"), :warn, ""
+  end
+
+  def test_column
+    assert_send_type "() -> ::Integer?",
+                     Ripper.new("def a; end"), :column
+  end
+
+  def test_debug_output
+    assert_send_type "() -> untyped",
+                     Ripper.new("def a; end"), :debug_output
+  end
+
+  def test_debug_output=
+    assert_send_type "(untyped) -> untyped",
+                     Ripper.new("def a; end"), :debug_output=, true
+  end
+
+  def test_encoding
+    assert_send_type "() -> ::Encoding",
+                     Ripper.new("def a; end"), :encoding
+  end
+
+  def test_end_seen?
+    assert_send_type "() -> bool",
+                     Ripper.new("def a; end"), :end_seen?
+  end
+
+  def test_error?
+    assert_send_type "() -> bool",
+                     Ripper.new("def a; end"), :error?
+  end
+
+  def test_filename
+    assert_send_type "() -> ::String",
+                     Ripper.new("def a; end"), :filename
+  end
+
+  def test_lineno
+    assert_send_type "() -> ::Integer?",
+                     Ripper.new("def a; end"), :lineno
+  end
+
+  def test__dispatch_0
+    assert_send_type "() -> void",
+                     Ripper.new("def a; end"), :_dispatch_0
+  end
+
+  def test__dispatch_1
+    assert_send_type "(untyped a) -> void",
+                     Ripper.new("def a; end"), :_dispatch_1, ""
+  end
+
+  def test__dispatch_2
+    assert_send_type "(untyped a, untyped b) -> void",
+                     Ripper.new("def a; end"), :_dispatch_2, "", ""
+  end
+
+  def test__dispatch_3
+    assert_send_type "(untyped a, untyped b, untyped c) -> void",
+                     Ripper.new("def a; end"), :_dispatch_3, "", "", ""
+  end
+
+  def test__dispatch_4
+    assert_send_type "(untyped a, untyped b, untyped c, untyped d) -> void",
+                     Ripper.new("def a; end"), :_dispatch_4, "", "", "", ""
+  end
+
+  def test__dispatch_5
+    assert_send_type "(untyped a, untyped b, untyped c, untyped d, untyped e) -> void",
+                     Ripper.new("def a; end"), :_dispatch_5, "", "", "", "", ""
+  end
+
+  def test__dispatch_6
+    assert_send_type "(untyped a, untyped b, untyped c, untyped d, untyped e, untyped f) -> void",
+                     Ripper.new("def a; end"), :_dispatch_6, "", "", "", "", "", ""
+  end
+
+  def test__dispatch_7
+    assert_send_type "(untyped a, untyped b, untyped c, untyped d, untyped e, untyped f, untyped g) -> void",
+                     Ripper.new("def a; end"), :_dispatch_7, "", "", "", "", "", "", ""
+  end
+
+  def test_parse
+    assert_send_type "() -> nil",
+                     Ripper.new("def a; end"), :parse
+  end
+
+  def test_state
+    assert_send_type "() -> ::Integer?",
+                     Ripper.new("def a; end"), :state
+  end
+
+  def test_token
+    assert_send_type "() -> ::String?",
+                     Ripper.new("def a; end"), :token
+  end
+
+  def test_yydebug
+    assert_send_type "() -> bool",
+                     Ripper.new("def a; end"), :yydebug
+  end
+
+  def test_yydebug=
+    assert_send_type "(bool) -> bool",
+                     Ripper.new("def a; end"), :yydebug=, true
+  end
+
+  def test_compile_error
+    assert_send_type "(untyped msg) -> untyped",
+                     Ripper.new("def a; end"), :compile_error, ""
+  end
+
+  def test_dedent_string
+    assert_send_type "(String input, Integer width) -> Integer",
+                     Ripper.new("def a; end"), :dedent_string, "", 0
+  end
+
+  def test_warning
+    assert_send_type "(untyped fmt, *untyped args) -> untyped",
+                     Ripper.new("def a; end"), :warning, ""
+  end
+end
+
+class Ripper::FilterSingletonTest < Test::Unit::TestCase
+  include TypeAssertions
+
+  library "ripper"
+  testing "singleton(::Ripper::Filter)"
+
+  def test_new
+    assert_send_type "(::File | ::Ripper::_Gets | ::String src, ?::String filename, ?::Integer lineno) -> ::Ripper::Filter",
+                     Ripper::Filter, :new, "def a; end"
+  end
+end
+
+class Ripper::FilterTest < Test::Unit::TestCase
+  include TypeAssertions
+
+  library "ripper"
+  testing "::Ripper::Filter"
+
+  def test_column
+    assert_send_type "() -> ::Integer?",
+                     Ripper::Filter.new("def a; end"), :column
+  end
+
+  def test_filename
+    assert_send_type "() -> ::String",
+                     Ripper::Filter.new("def a; end").tap(&:parse), :filename
+  end
+
+  def test_lineno
+    assert_send_type "() -> ::Integer?",
+                     Ripper::Filter.new("def a; end").tap(&:parse), :lineno
+  end
+
+  def test_parse
+    assert_send_type "(?untyped init) -> untyped",
+                     Ripper::Filter.new("def a; end"), :parse
+  end
+
+  def test_state
+    assert_send_type "() -> untyped",
+                     Ripper::Filter.new("def a; end").tap(&:parse), :state
+  end
+end