class ReplTypeCompletor::Types::SingletonType::InstanceType

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 238
def initialize(klass, params = nil, instances = nil)
  @klass = klass
  @raw_params = params if params && !params.empty?
  @instances = instances if instances && !instances.empty?
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 246
  def all_methods() = rbs_methods.keys | @klass.instance_methods | @klass.private_instance_methods | singleton_methods | instances_private_methods

  def singleton_methods
    return [] unless @instances
    @singleton_methods ||= @instances.map do |instance|
      Methods::OBJECT_SINGLETON_METHODS_METHOD.bind_call(instance)
    end.inject(:|)
  end

  def instances_private_methods
    return [] unless @instances
    @private_instances_methods ||= @instances.map do |instance|
      Methods::OBJECT_PRIVATE_METHODS_METHOD.bind_call(instance, false)
    end.inject(:|)
  end

  def params
    @params ||= expand_params
  end

  def expand_params
    params = @raw_params || {}
    return params unless @instances

    if @klass == Array
      type = Types.union_type_from_objects(@instances.flatten(1))
      { Elem: UnionType[*params[:Elem], *type] }
    elsif @klass == Hash
      key = Types.union_type_from_objects(@instances.map(&:keys).flatten(1))
      value = Types.union_type_from_objects(@instances.map(&:values).flatten(1))
      {
        K: UnionType[*params[:K], key],
        V: UnionType[*params[:V], value]
      }
    else
      params
    end
  end

  def constants() = []
  def types() = [self]
  def nillable?() = (@klass == NilClass)
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

NIL = InstanceType.new NilClass
OBJECT = InstanceType.new Object
TRUE = InstanceType.new TrueClass
FALSE = InstanceType.new FalseClass
SYMBOL = InstanceType.new Symbol
STRING = InstanceType.new String
INTEGER = InstanceType.new Integer
RANGE = InstanceType.new Range
REGEXP = InstanceType.new Regexp
FLOAT = InstanceType.new Float
RATIONAL = InstanceType.new Rational
COMPLEX = InstanceType.new Complex
ARRAY = InstanceType.new Array
HASH = InstanceType.new Hash
CLASS = InstanceType.new Class
MODULE = InstanceType.new Module
PROC = InstanceType.new Proc

class UnionType
  attr_reader :types

  def initialize(*types)
    @types = []
    singleton_types = []
    instance_types = {}
    collect = -> type do
      case type
      in UnionType
        type.types.each(&collect)
      in InstanceType
        params, instances = (instance_types[type.klass] ||= [{}, []])
        type.instances&.each { instances << _1 }
        type.raw_params&.each do |k, v|
          (params[k] ||= []) << v
        end
      in SingletonType
        singleton_types << type
      end
    end
    types.each(&collect)
    @types = singleton_types.uniq + instance_types.map do |klass, (params, instances)|
      params = params.transform_values { |v| UnionType[*v] }
      InstanceType.new(klass, params, instances)
    end
  end

  def transform(&block)
    UnionType[*types.map(&block)]
  end

  def nillable?
    types.any?(&:nillable?)
  end

  def nonnillable
    UnionType[*types.reject { _1.is_a?(InstanceType) && _1.klass == NilClass }]
  end

  def self.[](*types)
    type = new(*types)
    if type.types.empty?
      OBJECT
    elsif type.types.size == 1
      type.types.first
    else
      type
    end
  end

  def methods() = @types.flat_map(&:methods).uniq
  def all_methods() = @types.flat_map(&:all_methods).uniq
  def constants() = @types.flat_map(&:constants).uniq
  def inspect() = @types.map(&:inspect).sort.join(' | ')
end

BOOLEAN = UnionType[TRUE, FALSE]

def self.array_of(*types)
  type = types.size >= 2 ? UnionType[*types] : types.first || OBJECT
  InstanceType.new Array, Elem: type
end

def self.from_rbs_type(return_type, self_type, extra_vars = {})
  case return_type
  when RBS::Types::Bases::Self
    self_type
  when RBS::Types::Bases::Bottom, RBS::Types::Bases::Nil
    NIL
  when RBS::Types::Bases::Any, RBS::Types::Bases::Void
    OBJECT
  when RBS::Types::Bases::Class
    self_type.transform do |type|
      case type
      in SingletonType
        InstanceType.new(self_type.module_or_class.is_a?(Class) ? Class : Module)
      in InstanceType
        SingletonType.new type.klass
      end
    end
    UnionType[*types]
  when RBS::Types::Bases::Bool
    BOOLEAN
  when RBS::Types::Bases::Instance
    self_type.transform do |type|
      if type.is_a?(SingletonType) && type.module_or_class.is_a?(Class)
        InstanceType.new type.module_or_class
      elsif type.is_a?(InstanceType)
        InstanceType.new type.klass
      else
        OBJECT
      end
    end
  when RBS::Types::Union, RBS::Types::Intersection
    # Intersection is unsupported. fallback to union type
    UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
  when RBS::Types::Proc
    PROC
  when RBS::Types::Tuple
    elem = UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
    InstanceType.new Array, Elem: elem
  when RBS::Types::Record
    InstanceType.new Hash, K: SYMBOL, V: OBJECT
  when RBS::Types::Literal
    InstanceType.new return_type.literal.class
  when RBS::Types::Variable
    if extra_vars.key? return_type.name
      extra_vars[return_type.name]
    elsif self_type.is_a? InstanceType
      self_type.params[return_type.name] || OBJECT
    elsif self_type.is_a? UnionType
      types = self_type.types.filter_map do |t|
        t.params[return_type.name] if t.is_a? InstanceType
      end
      UnionType[*types]
    else
      OBJECT
    end
  when RBS::Types::Optional
    UnionType[from_rbs_type(return_type.type, self_type, extra_vars), NIL]
  when RBS::Types::Alias
    case return_type.name.name
    when :int
      INTEGER
    when :boolish
      BOOLEAN
    when :string
      STRING
    else
      # TODO: ???
      OBJECT
    end
  when RBS::Types::Interface
    # unimplemented
    OBJECT
  when RBS::Types::ClassInstance
    klass = return_type.name.to_namespace.path.reduce(Object) { _1.const_get _2 }
    if return_type.args
      args = return_type.args.map { from_rbs_type _1, self_type, extra_vars }
      names = rbs_builder.build_singleton(return_type.name).type_params
      params = names.map.with_index { [_1, args[_2] || OBJECT] }.to_h
    end
    InstanceType.new klass, params || {}
  else
    OBJECT
  end
end

def self.method_return_bottom?(method)
  method.type.return_type.is_a? RBS::Types::Bases::Bottom
end

def self.match_free_variables(vars, types, values)
  accumulator = {}
  types.zip values do |t, v|
    _match_free_variable(vars, t, v, accumulator) if v
  end
  accumulator.transform_values { UnionType[*_1] }
end

def self._match_free_variable(vars, rbs_type, value, accumulator)
  case [rbs_type, value]
  in [RBS::Types::Variable,]
    (accumulator[rbs_type.name] ||= []) << value if vars.include? rbs_type.name
  in [RBS::Types::ClassInstance, InstanceType]
    names = rbs_builder.build_singleton(rbs_type.name).type_params
    names.zip(rbs_type.args).each do |name, arg|
      v = value.params[name]
      _match_free_variable vars, arg, v, accumulator if v
    end
  in [RBS::Types::Tuple, InstanceType] if value.klass == Array
    v = value.params[:Elem]
    rbs_type.types.each do |t|
      _match_free_variable vars, t, v, accumulator
    end
  in [RBS::Types::Record, InstanceType] if value.klass == Hash
    # TODO
  in [RBS::Types::Interface,]
    definition = rbs_builder.build_interface rbs_type.name
    convert = {}
    definition.type_params.zip(rbs_type.args).each do |from, arg|
      convert[from] = arg.name if arg.is_a? RBS::Types::Variable
    end
    return if convert.empty?
    ac = {}
    definition.methods.each do |method_name, method|
      return_type = method_return_type value, method_name
      method.defs.each do |method_def|
        interface_return_type = method_def.type.type.return_type
        _match_free_variable convert, interface_return_type, return_type, ac
      end
    end
    convert.each do |from, to|
      values = ac[from]
      (accumulator[to] ||= []).concat values if values
    end
  

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 285
  def constants() = []
  def types() = [self]
  def nillable?() = (@klass == NilClass)
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

NIL = InstanceType.new NilClass
OBJECT = InstanceType.new Object
TRUE = InstanceType.new TrueClass
FALSE = InstanceType.new FalseClass
SYMBOL = InstanceType.new Symbol
STRING = InstanceType.new String
INTEGER = InstanceType.new Integer
RANGE = InstanceType.new Range
REGEXP = InstanceType.new Regexp
FLOAT = InstanceType.new Float
RATIONAL = InstanceType.new Rational
COMPLEX = InstanceType.new Complex
ARRAY = InstanceType.new Array
HASH = InstanceType.new Hash
CLASS = InstanceType.new Class
MODULE = InstanceType.new Module
PROC = InstanceType.new Proc

class UnionType
  attr_reader :types

  def initialize(*types)
    @types = []
    singleton_types = []
    instance_types = {}
    collect = -> type do
      case type
      in UnionType
        type.types.each(&collect)
      in InstanceType
        params, instances = (instance_types[type.klass] ||= [{}, []])
        type.instances&.each { instances << _1 }
        type.raw_params&.each do |k, v|
          (params[k] ||= []) << v
        end
      in SingletonType
        singleton_types << type
      end
    end
    types.each(&collect)
    @types = singleton_types.uniq + instance_types.map do |klass, (params, instances)|
      params = params.transform_values { |v| UnionType[*v] }
      InstanceType.new(klass, params, instances)
    end
  end

  def transform(&block)
    UnionType[*types.map(&block)]
  end

  def nillable?
    types.any?(&:nillable?)
  end

  def nonnillable
    UnionType[*types.reject { _1.is_a?(InstanceType) && _1.klass == NilClass }]
  end

  def self.[](*types)
    type = new(*types)
    if type.types.empty?
      OBJECT
    elsif type.types.size == 1
      type.types.first
    else
      type
    end
  end

  def methods() = @types.flat_map(&:methods).uniq
  def all_methods() = @types.flat_map(&:all_methods).uniq
  def constants() = @types.flat_map(&:constants).uniq
  def inspect() = @types.map(&:inspect).sort.join(' | ')
end

BOOLEAN = UnionType[TRUE, FALSE]

def self.array_of(*types)
  type = types.size >= 2 ? UnionType[*types] : types.first || OBJECT
  InstanceType.new Array, Elem: type
end

def self.from_rbs_type(return_type, self_type, extra_vars = {})
  case return_type
  when RBS::Types::Bases::Self
    self_type
  when RBS::Types::Bases::Bottom, RBS::Types::Bases::Nil
    NIL
  when RBS::Types::Bases::Any, RBS::Types::Bases::Void
    OBJECT
  when RBS::Types::Bases::Class
    self_type.transform do |type|
      case type
      in SingletonType
        InstanceType.new(self_type.module_or_class.is_a?(Class) ? Class : Module)
      in InstanceType
        SingletonType.new type.klass
      end
    end
    UnionType[*types]
  when RBS::Types::Bases::Bool
    BOOLEAN
  when RBS::Types::Bases::Instance
    self_type.transform do |type|
      if type.is_a?(SingletonType) && type.module_or_class.is_a?(Class)
        InstanceType.new type.module_or_class
      elsif type.is_a?(InstanceType)
        InstanceType.new type.klass
      else
        OBJECT
      end
    end
  when RBS::Types::Union, RBS::Types::Intersection
    # Intersection is unsupported. fallback to union type
    UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
  when RBS::Types::Proc
    PROC
  when RBS::Types::Tuple
    elem = UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
    InstanceType.new Array, Elem: elem
  when RBS::Types::Record
    InstanceType.new Hash, K: SYMBOL, V: OBJECT
  when RBS::Types::Literal
    InstanceType.new return_type.literal.class
  when RBS::Types::Variable
    if extra_vars.key? return_type.name
      extra_vars[return_type.name]
    elsif self_type.is_a? InstanceType
      self_type.params[return_type.name] || OBJECT
    elsif self_type.is_a? UnionType
      types = self_type.types.filter_map do |t|
        t.params[return_type.name] if t.is_a? InstanceType
      end
      UnionType[*types]
    else
      OBJECT
    end
  when RBS::Types::Optional
    UnionType[from_rbs_type(return_type.type, self_type, extra_vars), NIL]
  when RBS::Types::Alias
    case return_type.name.name
    when :int
      INTEGER
    when :boolish
      BOOLEAN
    when :string
      STRING
    else
      # TODO: ???
      OBJECT
    end
  when RBS::Types::Interface
    # unimplemented
    OBJECT
  when RBS::Types::ClassInstance
    klass = return_type.name.to_namespace.path.reduce(Object) { _1.const_get _2 }
    if return_type.args
      args = return_type.args.map { from_rbs_type _1, self_type, extra_vars }
      names = rbs_builder.build_singleton(return_type.name).type_params
      params = names.map.with_index { [_1, args[_2] || OBJECT] }.to_h
    end
    InstanceType.new klass, params || {}
  else
    OBJECT
  end
end

def self.method_return_bottom?(method)
  method.type.return_type.is_a? RBS::Types::Bases::Bottom
end

def self.match_free_variables(vars, types, values)
  accumulator = {}
  types.zip values do |t, v|
    _match_free_variable(vars, t, v, accumulator) if v
  end
  accumulator.transform_values { UnionType[*_1] }
end

def self._match_free_variable(vars, rbs_type, value, accumulator)
  case [rbs_type, value]
  in [RBS::Types::Variable,]
    (accumulator[rbs_type.name] ||= []) << value if vars.include? rbs_type.name
  in [RBS::Types::ClassInstance, InstanceType]
    names = rbs_builder.build_singleton(rbs_type.name).type_params
    names.zip(rbs_type.args).each do |name, arg|
      v = value.params[name]
      _match_free_variable vars, arg, v, accumulator if v
    end
  in [RBS::Types::Tuple, InstanceType] if value.klass == Array
    v = value.params[:Elem]
    rbs_type.types.each do |t|
      _match_free_variable vars, t, v, accumulator
    end
  in [RBS::Types::Record, InstanceType] if value.klass == Hash
    # TODO
  in [RBS::Types::Interface,]
    definition = rbs_builder.build_interface rbs_type.name
    convert = {}
    definition.type_params.zip(rbs_type.args).each do |from, arg|
      convert[from] = arg.name if arg.is_a? RBS::Types::Variable
    end
    return if convert.empty?
    ac = {}
    definition.methods.each do |method_name, method|
      return_type = method_return_type value, method_name
      method.defs.each do |method_def|
        interface_return_type = method_def.type.type.return_type
        _match_free_variable convert, interface_return_type, return_type, ac
      end
    end
    convert.each do |from, to|
      values = ac[from]
      (accumulator[to] ||= []).concat values if values
    end
  else

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 266
def expand_params
  params = @raw_params || {}
  return params unless @instances

  if @klass == Array
    type = Types.union_type_from_objects(@instances.flatten(1))
    { Elem: UnionType[*params[:Elem], *type] }
  elsif @klass == Hash
    key = Types.union_type_from_objects(@instances.map(&:keys).flatten(1))
    value = Types.union_type_from_objects(@instances.map(&:values).flatten(1))
    {
      K: UnionType[*params[:K], key],
      V: UnionType[*params[:V], value]
    }
  else
    params
  end
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 298
def inspect
  if !@params && (@klass == Array || @klass == Hash) && @instances
    "#{inspect_without_params}[unresolved]"
  elsif params.empty?
    inspect_without_params
  else
    params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
    "#{inspect_without_params}#{params_string}"
  end
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 309
def inspect_without_params
  if klass == NilClass
    'nil'
  elsif klass == TrueClass
    'true'
  elsif klass == FalseClass
    'false'
  else
    klass.to_s
  end
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 255
def instances_private_methods
  return [] unless @instances
  @private_instances_methods ||= @instances.map do |instance|
    Methods::OBJECT_PRIVATE_METHODS_METHOD.bind_call(instance, false)
  end.inject(:|)
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 245
  def methods() = rbs_methods.select { _2.public? }.keys | @klass.instance_methods | singleton_methods
  def all_methods() = rbs_methods.keys | @klass.instance_methods | @klass.private_instance_methods | singleton_methods | instances_private_methods

  def singleton_methods
    return [] unless @instances
    @singleton_methods ||= @instances.map do |instance|
      Methods::OBJECT_SINGLETON_METHODS_METHOD.bind_call(instance)
    end.inject(:|)
  end

  def instances_private_methods
    return [] unless @instances
    @private_instances_methods ||= @instances.map do |instance|
      Methods::OBJECT_PRIVATE_METHODS_METHOD.bind_call(instance, false)
    end.inject(:|)
  end

  def params
    @params ||= expand_params
  end

  def expand_params
    params = @raw_params || {}
    return params unless @instances

    if @klass == Array
      type = Types.union_type_from_objects(@instances.flatten(1))
      { Elem: UnionType[*params[:Elem], *type] }
    elsif @klass == Hash
      key = Types.union_type_from_objects(@instances.map(&:keys).flatten(1))
      value = Types.union_type_from_objects(@instances.map(&:values).flatten(1))
      {
        K: UnionType[*params[:K], key],
        V: UnionType[*params[:V], value]
      }
    else
      params
    end
  end

  def constants() = []
  def types() = [self]
  def nillable?() = (@klass == NilClass)
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

NIL = InstanceType.new NilClass
OBJECT = InstanceType.new Object
TRUE = InstanceType.new TrueClass
FALSE = InstanceType.new FalseClass
SYMBOL = InstanceType.new Symbol
STRING = InstanceType.new String
INTEGER = InstanceType.new Integer
RANGE = InstanceType.new Range
REGEXP = InstanceType.new Regexp
FLOAT = InstanceType.new Float
RATIONAL = InstanceType.new Rational
COMPLEX = InstanceType.new Complex
ARRAY = InstanceType.new Array
HASH = InstanceType.new Hash
CLASS = InstanceType.new Class
MODULE = InstanceType.new Module
PROC = InstanceType.new Proc

class UnionType
  attr_reader :types

  def initialize(*types)
    @types = []
    singleton_types = []
    instance_types = {}
    collect = -> type do
      case type
      in UnionType
        type.types.each(&collect)
      in InstanceType
        params, instances = (instance_types[type.klass] ||= [{}, []])
        type.instances&.each { instances << _1 }
        type.raw_params&.each do |k, v|
          (params[k] ||= []) << v
        end
      in SingletonType
        singleton_types << type
      end
    end
    types.each(&collect)
    @types = singleton_types.uniq + instance_types.map do |klass, (params, instances)|
      params = params.transform_values { |v| UnionType[*v] }
      InstanceType.new(klass, params, instances)
    end
  end

  def transform(&block)
    UnionType[*types.map(&block)]
  end

  def nillable?
    types.any?(&:nillable?)
  end

  def nonnillable
    UnionType[*types.reject { _1.is_a?(InstanceType) && _1.klass == NilClass }]
  end

  def self.[](*types)
    type = new(*types)
    if type.types.empty?
      OBJECT
    elsif type.types.size == 1
      type.types.first
    else
      type
    end
  end

  def methods() = @types.flat_map(&:methods).uniq
  def all_methods() = @types.flat_map(&:all_methods).uniq
  def constants() = @types.flat_map(&:constants).uniq
  def inspect() = @types.map(&:inspect).sort.join(' | ')
end

BOOLEAN = UnionType[TRUE, FALSE]

def self.array_of(*types)
  type = types.size >= 2 ? UnionType[*types] : types.first || OBJECT
  InstanceType.new Array, Elem: type
end

def self.from_rbs_type(return_type, self_type, extra_vars = {})
  case return_type
  when RBS::Types::Bases::Self
    self_type
  when RBS::Types::Bases::Bottom, RBS::Types::Bases::Nil
    NIL
  when RBS::Types::Bases::Any, RBS::Types::Bases::Void
    OBJECT
  when RBS::Types::Bases::Class
    self_type.transform do |type|
      case type
      in SingletonType
        InstanceType.new(self_type.module_or_class.is_a?(Class) ? Class : Module)
      in InstanceType
        SingletonType.new type.klass
      end
    end
    UnionType[*types]
  when RBS::Types::Bases::Bool
    BOOLEAN
  when RBS::Types::Bases::Instance
    self_type.transform do |type|
      if type.is_a?(SingletonType) && type.module_or_class.is_a?(Class)
        InstanceType.new type.module_or_class
      elsif type.is_a?(InstanceType)
        InstanceType.new type.klass
      else
        OBJECT
      end
    end
  when RBS::Types::Union, RBS::Types::Intersection
    # Intersection is unsupported. fallback to union type
    UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
  when RBS::Types::Proc
    PROC
  when RBS::Types::Tuple
    elem = UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
    InstanceType.new Array, Elem: elem
  when RBS::Types::Record
    InstanceType.new Hash, K: SYMBOL, V: OBJECT
  when RBS::Types::Literal
    InstanceType.new return_type.literal.class
  when RBS::Types::Variable
    if extra_vars.key? return_type.name
      extra_vars[return_type.name]
    elsif self_type.is_a? InstanceType
      self_type.params[return_type.name] || OBJECT
    elsif self_type.is_a? UnionType
      types = self_type.types.filter_map do |t|
        t.params[return_type.name] if t.is_a? InstanceType
      end
      UnionType[*types]
    else
      OBJECT
    end
  when RBS::Types::Optional
    UnionType[from_rbs_type(return_type.type, self_type, extra_vars), NIL]
  when RBS::Types::Alias
    case return_type.name.name
    when :int
      INTEGER
    when :boolish
      BOOLEAN
    when :string
      STRING
    else
      # TODO: ???
      OBJECT
    end
  when RBS::Types::Interface
    # unimplemented
    OBJECT
  when RBS::Types::ClassInstance
    klass = return_type.name.to_namespace.path.reduce(Object) { _1.const_get _2 }
    if return_type.args
      args = return_type.args.map { from_rbs_type _1, self_type, extra_vars }
      names = rbs_builder.build_singleton(return_type.name).type_params
      params = names.map.with_index { [_1, args[_2] || OBJECT] }.to_h
    end
    InstanceType.new klass, params || {}
  else
    OBJECT
  end
end

def self.method_return_bottom?(method)
  method.type.return_type.is_a? RBS::Types::Bases::Bottom
end

def self.match_free_variables(vars, types, values)
  accumulator = {}
  types.zip values do |t, v|
    _match_free_variable(vars, t, v, accumulator) if v
  end
  accumulator.transform_values { UnionType[*_1] }
end

def self._match_free_variable(vars, rbs_type, value, accumulator)
  case [rbs_type, value]
  in [RBS::Types::Variable,]
    (accumulator[rbs_type.name] ||= []) << value if vars.include? rbs_type.name
  in [RBS::Types::ClassInstance, InstanceType]
    names = rbs_builder.build_singleton(rbs_type.name).type_params
    names.zip(rbs_type.args).each do |name, arg|
      v = value.params[name]
      _match_free_variable vars, arg, v, accumulator if v
    end
  in [RBS::Types::Tuple, InstanceType] if value.klass == Array
    v = value.params[:Elem]
    rbs_type.types.each do |t|
      _match_free_variable vars, t, v, accumulator
    end
  in [RBS::Types::Record, InstanceType] if value.klass == Hash
    # TODO
  in [RBS::Types::Interface,]
    definition = rbs_builder.build_interface rbs_type.name
    convert = {}
    definition.type_params.zip(rbs_type.args).each do |from, arg|
      convert[from] = arg.name if arg.is_a? RBS::Types::Variable
    end
    return if convert.empty?
    ac = {}
    definition.methods.each do |method_name, method|
      return_type = method_return_type value, method_name
      method.defs.each do |method_def|
        interface_return_type = method_def.type.type.return_type
        _match_free_variable convert, interface_return_type, return_type, ac
      end
    end
    convert.each do |from, to|
      values = ac[from]
      (accumulator[to] ||= []).concat values if values
    end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 287
  def nillable?() = (@klass == NilClass)
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

NIL = InstanceType.new NilClass
OBJECT = InstanceType.new Object
TRUE = InstanceType.new TrueClass
FALSE = InstanceType.new FalseClass
SYMBOL = InstanceType.new Symbol
STRING = InstanceType.new String
INTEGER = InstanceType.new Integer
RANGE = InstanceType.new Range
REGEXP = InstanceType.new Regexp
FLOAT = InstanceType.new Float
RATIONAL = InstanceType.new Rational
COMPLEX = InstanceType.new Complex
ARRAY = InstanceType.new Array
HASH = InstanceType.new Hash
CLASS = InstanceType.new Class
MODULE = InstanceType.new Module
PROC = InstanceType.new Proc

class UnionType
  attr_reader :types

  def initialize(*types)
    @types = []
    singleton_types = []
    instance_types = {}
    collect = -> type do
      case type
      in UnionType
        type.types.each(&collect)
      in InstanceType
        params, instances = (instance_types[type.klass] ||= [{}, []])
        type.instances&.each { instances << _1 }
        type.raw_params&.each do |k, v|
          (params[k] ||= []) << v
        end
      in SingletonType
        singleton_types << type
      end
    end
    types.each(&collect)
    @types = singleton_types.uniq + instance_types.map do |klass, (params, instances)|
      params = params.transform_values { |v| UnionType[*v] }
      InstanceType.new(klass, params, instances)
    end
  end

  def transform(&block)
    UnionType[*types.map(&block)]
  end

  def nillable?
    types.any?(&:nillable?)
  end

  def nonnillable
    UnionType[*types.reject { _1.is_a?(InstanceType) && _1.klass == NilClass }]
  end

  def self.[](*types)
    type = new(*types)
    if type.types.empty?
      OBJECT
    elsif type.types.size == 1
      type.types.first
    else
      type
    end
  end

  def methods() = @types.flat_map(&:methods).uniq
  def all_methods() = @types.flat_map(&:all_methods).uniq
  def constants() = @types.flat_map(&:constants).uniq
  def inspect() = @types.map(&:inspect).sort.join(' | ')
end

BOOLEAN = UnionType[TRUE, FALSE]

def self.array_of(*types)
  type = types.size >= 2 ? UnionType[*types] : types.first || OBJECT
  InstanceType.new Array, Elem: type
end

def self.from_rbs_type(return_type, self_type, extra_vars = {})
  case return_type
  when RBS::Types::Bases::Self
    self_type
  when RBS::Types::Bases::Bottom, RBS::Types::Bases::Nil
    NIL
  when RBS::Types::Bases::Any, RBS::Types::Bases::Void
    OBJECT
  when RBS::Types::Bases::Class
    self_type.transform do |type|
      case type
      in SingletonType
        InstanceType.new(self_type.module_or_class.is_a?(Class) ? Class : Module)
      in InstanceType
        SingletonType.new type.klass
      end
    end
    UnionType[*types]
  when RBS::Types::Bases::Bool
    BOOLEAN
  when RBS::Types::Bases::Instance
    self_type.transform do |type|
      if type.is_a?(SingletonType) && type.module_or_class.is_a?(Class)
        InstanceType.new type.module_or_class
      elsif type.is_a?(InstanceType)
        InstanceType.new type.klass
      else
        OBJECT
      end
    end
  when RBS::Types::Union, RBS::Types::Intersection
    # Intersection is unsupported. fallback to union type
    UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
  when RBS::Types::Proc
    PROC
  when RBS::Types::Tuple
    elem = UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
    InstanceType.new Array, Elem: elem
  when RBS::Types::Record
    InstanceType.new Hash, K: SYMBOL, V: OBJECT
  when RBS::Types::Literal
    InstanceType.new return_type.literal.class
  when RBS::Types::Variable
    if extra_vars.key? return_type.name
      extra_vars[return_type.name]
    elsif self_type.is_a? InstanceType
      self_type.params[return_type.name] || OBJECT
    elsif self_type.is_a? UnionType
      types = self_type.types.filter_map do |t|
        t.params[return_type.name] if t.is_a? InstanceType
      end
      UnionType[*types]
    else
      OBJECT
    end
  when RBS::Types::Optional
    UnionType[from_rbs_type(return_type.type, self_type, extra_vars), NIL]
  when RBS::Types::Alias
    case return_type.name.name
    when :int
      INTEGER
    when :boolish
      BOOLEAN
    when :string
      STRING
    else
      # TODO: ???
      OBJECT
    end
  when RBS::Types::Interface
    # unimplemented
    OBJECT
  when RBS::Types::ClassInstance
    klass = return_type.name.to_namespace.path.reduce(Object) { _1.const_get _2 }
    if return_type.args
      args = return_type.args.map { from_rbs_type _1, self_type, extra_vars }
      names = rbs_builder.build_singleton(return_type.name).type_params
      params = names.map.with_index { [_1, args[_2] || OBJECT] }.to_h
    end
    InstanceType.new klass, params || {}
  else
    OBJECT
  end
end

def self.method_return_bottom?(method)
  method.type.return_type.is_a? RBS::Types::Bases::Bottom
end

def self.match_free_variables(vars, types, values)
  accumulator = {}
  types.zip values do |t, v|
    _match_free_variable(vars, t, v, accumulator) if v
  end
  accumulator.transform_values { UnionType[*_1] }
end

def self._match_free_variable(vars, rbs_type, value, accumulator)
  case [rbs_type, value]
  in [RBS::Types::Variable,]
    (accumulator[rbs_type.name] ||= []) << value if vars.include? rbs_type.name
  in [RBS::Types::ClassInstance, InstanceType]
    names = rbs_builder.build_singleton(rbs_type.name).type_params
    names.zip(rbs_type.args).each do |name, arg|
      v = value.params[name]
      _match_free_variable vars, arg, v, accumulator if v
    end
  in [RBS::Types::Tuple, InstanceType] if value.klass == Array
    v = value.params[:Elem]
    rbs_type.types.each do |t|
      _match_free_variable vars, t, v, accumulator
    end
  in [RBS::Types::Record, InstanceType] if value.klass == Hash
    # TODO
  in [RBS::Types::Interface,]
    definition = rbs_builder.build_interface rbs_type.name
    convert = {}
    definition.type_params.zip(rbs_type.args).each do |from, arg|
      convert[from] = arg.name if arg.is_a? RBS::Types::Variable
    end
    return if convert.empty?
    ac = {}
    definition.methods.each do |method_name, method|
      return_type = method_return_type value, method_name
      method.defs.each do |method_def|
        interface_return_type = method_def.type.type.return_type
        _match_free_variable convert, interface_return_type, return_type, ac
      end
    end
    convert.each do |from, to|
      values = ac[from]
      (accumulator[to] ||= []).concat values if values
    end
  else
  end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 288
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 262
def params
  @params ||= expand_params
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 290
def rbs_methods
  return {} unless Types.rbs_builder

  name = Types.class_name_of(@klass)
  type_name = Types.rbs_absolute_type_name(name)
  Types.rbs_builder.build_instance(type_name).methods rescue {}
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 248
def singleton_methods
  return [] unless @instances
  @singleton_methods ||= @instances.map do |instance|
    Methods::OBJECT_SINGLETON_METHODS_METHOD.bind_call(instance)
  end.inject(:|)
end

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 244
  def transform() = yield(self)
  def methods() = rbs_methods.select { _2.public? }.keys | @klass.instance_methods | singleton_methods
  def all_methods() = rbs_methods.keys | @klass.instance_methods | @klass.private_instance_methods | singleton_methods | instances_private_methods

  def singleton_methods
    return [] unless @instances
    @singleton_methods ||= @instances.map do |instance|
      Methods::OBJECT_SINGLETON_METHODS_METHOD.bind_call(instance)
    end.inject(:|)
  end

  def instances_private_methods
    return [] unless @instances
    @private_instances_methods ||= @instances.map do |instance|
      Methods::OBJECT_PRIVATE_METHODS_METHOD.bind_call(instance, false)
    end.inject(:|)
  end

  def params
    @params ||= expand_params
  end

  def expand_params
    params = @raw_params || {}
    return params unless @instances

    if @klass == Array
      type = Types.union_type_from_objects(@instances.flatten(1))
      { Elem: UnionType[*params[:Elem], *type] }
    elsif @klass == Hash
      key = Types.union_type_from_objects(@instances.map(&:keys).flatten(1))
      value = Types.union_type_from_objects(@instances.map(&:values).flatten(1))
      {
        K: UnionType[*params[:K], key],
        V: UnionType[*params[:V], value]
      }
    else
      params
    end
  end

  def constants() = []
  def types() = [self]
  def nillable?() = (@klass == NilClass)
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

NIL = InstanceType.new NilClass
OBJECT = InstanceType.new Object
TRUE = InstanceType.new TrueClass
FALSE = InstanceType.new FalseClass
SYMBOL = InstanceType.new Symbol
STRING = InstanceType.new String
INTEGER = InstanceType.new Integer
RANGE = InstanceType.new Range
REGEXP = InstanceType.new Regexp
FLOAT = InstanceType.new Float
RATIONAL = InstanceType.new Rational
COMPLEX = InstanceType.new Complex
ARRAY = InstanceType.new Array
HASH = InstanceType.new Hash
CLASS = InstanceType.new Class
MODULE = InstanceType.new Module
PROC = InstanceType.new Proc

class UnionType
  attr_reader :types

  def initialize(*types)
    @types = []
    singleton_types = []
    instance_types = {}
    collect = -> type do
      case type
      in UnionType
        type.types.each(&collect)
      in InstanceType
        params, instances = (instance_types[type.klass] ||= [{}, []])
        type.instances&.each { instances << _1 }
        type.raw_params&.each do |k, v|
          (params[k] ||= []) << v
        end
      in SingletonType
        singleton_types << type
      end
    end
    types.each(&collect)
    @types = singleton_types.uniq + instance_types.map do |klass, (params, instances)|
      params = params.transform_values { |v| UnionType[*v] }
      InstanceType.new(klass, params, instances)
    end
  end

  def transform(&block)
    UnionType[*types.map(&block)]
  end

  def nillable?
    types.any?(&:nillable?)
  end

  def nonnillable
    UnionType[*types.reject { _1.is_a?(InstanceType) && _1.klass == NilClass }]
  end

  def self.[](*types)
    type = new(*types)
    if type.types.empty?
      OBJECT
    elsif type.types.size == 1
      type.types.first
    else
      type
    end
  end

  def methods() = @types.flat_map(&:methods).uniq
  def all_methods() = @types.flat_map(&:all_methods).uniq
  def constants() = @types.flat_map(&:constants).uniq
  def inspect() = @types.map(&:inspect).sort.join(' | ')
end

BOOLEAN = UnionType[TRUE, FALSE]

def self.array_of(*types)
  type = types.size >= 2 ? UnionType[*types] : types.first || OBJECT
  InstanceType.new Array, Elem: type
end

def self.from_rbs_type(return_type, self_type, extra_vars = {})
  case return_type
  when RBS::Types::Bases::Self
    self_type
  when RBS::Types::Bases::Bottom, RBS::Types::Bases::Nil
    NIL
  when RBS::Types::Bases::Any, RBS::Types::Bases::Void
    OBJECT
  when RBS::Types::Bases::Class
    self_type.transform do |type|
      case type
      in SingletonType
        InstanceType.new(self_type.module_or_class.is_a?(Class) ? Class : Module)
      in InstanceType
        SingletonType.new type.klass
      end
    end
    UnionType[*types]
  when RBS::Types::Bases::Bool
    BOOLEAN
  when RBS::Types::Bases::Instance
    self_type.transform do |type|
      if type.is_a?(SingletonType) && type.module_or_class.is_a?(Class)
        InstanceType.new type.module_or_class
      elsif type.is_a?(InstanceType)
        InstanceType.new type.klass
      else
        OBJECT
      end
    end
  when RBS::Types::Union, RBS::Types::Intersection
    # Intersection is unsupported. fallback to union type
    UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
  when RBS::Types::Proc
    PROC
  when RBS::Types::Tuple
    elem = UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
    InstanceType.new Array, Elem: elem
  when RBS::Types::Record
    InstanceType.new Hash, K: SYMBOL, V: OBJECT
  when RBS::Types::Literal
    InstanceType.new return_type.literal.class
  when RBS::Types::Variable
    if extra_vars.key? return_type.name
      extra_vars[return_type.name]
    elsif self_type.is_a? InstanceType
      self_type.params[return_type.name] || OBJECT
    elsif self_type.is_a? UnionType
      types = self_type.types.filter_map do |t|
        t.params[return_type.name] if t.is_a? InstanceType
      end
      UnionType[*types]
    else
      OBJECT
    end
  when RBS::Types::Optional
    UnionType[from_rbs_type(return_type.type, self_type, extra_vars), NIL]
  when RBS::Types::Alias
    case return_type.name.name
    when :int
      INTEGER
    when :boolish
      BOOLEAN
    when :string
      STRING
    else
      # TODO: ???
      OBJECT
    end
  when RBS::Types::Interface
    # unimplemented
    OBJECT
  when RBS::Types::ClassInstance
    klass = return_type.name.to_namespace.path.reduce(Object) { _1.const_get _2 }
    if return_type.args
      args = return_type.args.map { from_rbs_type _1, self_type, extra_vars }
      names = rbs_builder.build_singleton(return_type.name).type_params
      params = names.map.with_index { [_1, args[_2] || OBJECT] }.to_h
    end
    InstanceType.new klass, params || {}
  else
    OBJECT
  end
end

def self.method_return_bottom?(method)
  method.type.return_type.is_a? RBS::Types::Bases::Bottom
end

def self.match_free_variables(vars, types, values)
  accumulator = {}
  types.zip values do |t, v|
    _match_free_variable(vars, t, v, accumulator) if v
  end
  accumulator.transform_values { UnionType[*_1] }
end

def self._match_free_variable(vars, rbs_type, value, accumulator)
  case [rbs_type, value]
  in [RBS::Types::Variable,]
    (accumulator[rbs_type.name] ||= []) << value if vars.include? rbs_type.name
  in [RBS::Types::ClassInstance, InstanceType]
    names = rbs_builder.build_singleton(rbs_type.name).type_params
    names.zip(rbs_type.args).each do |name, arg|
      v = value.params[name]
      _match_free_variable vars, arg, v, accumulator if v
    end
  in [RBS::Types::Tuple, InstanceType] if value.klass == Array
    v = value.params[:Elem]
    rbs_type.types.each do |t|
      _match_free_variable vars, t, v, accumulator
    end
  in [RBS::Types::Record, InstanceType] if value.klass == Hash
    # TODO
  in [RBS::Types::Interface,]
    definition = rbs_builder.build_interface rbs_type.name
    convert = {}
    definition.type_params.zip(rbs_type.args).each do |from, arg|
      convert[from] = arg.name if arg.is_a? RBS::Types::Variable
    end
    return if convert.empty?
    ac = {}
    definition.methods.each do |method_name, method|
      return_type = method_return_type value, method_name
      method.defs.each do |method_def|
        interface_return_type = method_def.type.type.return_type
        _match_free_variable convert, interface_return_type, return_type, ac
      end
    end
    convert.each do |from, to|
      values = ac[from]
      (accumulator[to] ||= []).concat values if values

# File bundled-src/repl_type_completor-0.1.12/lib/repl_type_completor/types.rb, line 286
  def types() = [self]
  def nillable?() = (@klass == NilClass)
  def nonnillable() = self

  def rbs_methods
    return {} unless Types.rbs_builder

    name = Types.class_name_of(@klass)
    type_name = Types.rbs_absolute_type_name(name)
    Types.rbs_builder.build_instance(type_name).methods rescue {}
  end

  def inspect
    if !@params && (@klass == Array || @klass == Hash) && @instances
      "#{inspect_without_params}[unresolved]"
    elsif params.empty?
      inspect_without_params
    else
      params_string = "[#{params.map { "#{_1}: #{_2.inspect}" }.join(', ')}]"
      "#{inspect_without_params}#{params_string}"
    end
  end

  def inspect_without_params
    if klass == NilClass
      'nil'
    elsif klass == TrueClass
      'true'
    elsif klass == FalseClass
      'false'
    else
      klass.to_s
    end
  end
end

NIL = InstanceType.new NilClass
OBJECT = InstanceType.new Object
TRUE = InstanceType.new TrueClass
FALSE = InstanceType.new FalseClass
SYMBOL = InstanceType.new Symbol
STRING = InstanceType.new String
INTEGER = InstanceType.new Integer
RANGE = InstanceType.new Range
REGEXP = InstanceType.new Regexp
FLOAT = InstanceType.new Float
RATIONAL = InstanceType.new Rational
COMPLEX = InstanceType.new Complex
ARRAY = InstanceType.new Array
HASH = InstanceType.new Hash
CLASS = InstanceType.new Class
MODULE = InstanceType.new Module
PROC = InstanceType.new Proc

class UnionType
  attr_reader :types

  def initialize(*types)
    @types = []
    singleton_types = []
    instance_types = {}
    collect = -> type do
      case type
      in UnionType
        type.types.each(&collect)
      in InstanceType
        params, instances = (instance_types[type.klass] ||= [{}, []])
        type.instances&.each { instances << _1 }
        type.raw_params&.each do |k, v|
          (params[k] ||= []) << v
        end
      in SingletonType
        singleton_types << type
      end
    end
    types.each(&collect)
    @types = singleton_types.uniq + instance_types.map do |klass, (params, instances)|
      params = params.transform_values { |v| UnionType[*v] }
      InstanceType.new(klass, params, instances)
    end
  end

  def transform(&block)
    UnionType[*types.map(&block)]
  end

  def nillable?
    types.any?(&:nillable?)
  end

  def nonnillable
    UnionType[*types.reject { _1.is_a?(InstanceType) && _1.klass == NilClass }]
  end

  def self.[](*types)
    type = new(*types)
    if type.types.empty?
      OBJECT
    elsif type.types.size == 1
      type.types.first
    else
      type
    end
  end

  def methods() = @types.flat_map(&:methods).uniq
  def all_methods() = @types.flat_map(&:all_methods).uniq
  def constants() = @types.flat_map(&:constants).uniq
  def inspect() = @types.map(&:inspect).sort.join(' | ')
end

BOOLEAN = UnionType[TRUE, FALSE]

def self.array_of(*types)
  type = types.size >= 2 ? UnionType[*types] : types.first || OBJECT
  InstanceType.new Array, Elem: type
end

def self.from_rbs_type(return_type, self_type, extra_vars = {})
  case return_type
  when RBS::Types::Bases::Self
    self_type
  when RBS::Types::Bases::Bottom, RBS::Types::Bases::Nil
    NIL
  when RBS::Types::Bases::Any, RBS::Types::Bases::Void
    OBJECT
  when RBS::Types::Bases::Class
    self_type.transform do |type|
      case type
      in SingletonType
        InstanceType.new(self_type.module_or_class.is_a?(Class) ? Class : Module)
      in InstanceType
        SingletonType.new type.klass
      end
    end
    UnionType[*types]
  when RBS::Types::Bases::Bool
    BOOLEAN
  when RBS::Types::Bases::Instance
    self_type.transform do |type|
      if type.is_a?(SingletonType) && type.module_or_class.is_a?(Class)
        InstanceType.new type.module_or_class
      elsif type.is_a?(InstanceType)
        InstanceType.new type.klass
      else
        OBJECT
      end
    end
  when RBS::Types::Union, RBS::Types::Intersection
    # Intersection is unsupported. fallback to union type
    UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
  when RBS::Types::Proc
    PROC
  when RBS::Types::Tuple
    elem = UnionType[*return_type.types.map { from_rbs_type _1, self_type, extra_vars }]
    InstanceType.new Array, Elem: elem
  when RBS::Types::Record
    InstanceType.new Hash, K: SYMBOL, V: OBJECT
  when RBS::Types::Literal
    InstanceType.new return_type.literal.class
  when RBS::Types::Variable
    if extra_vars.key? return_type.name
      extra_vars[return_type.name]
    elsif self_type.is_a? InstanceType
      self_type.params[return_type.name] || OBJECT
    elsif self_type.is_a? UnionType
      types = self_type.types.filter_map do |t|
        t.params[return_type.name] if t.is_a? InstanceType
      end
      UnionType[*types]
    else
      OBJECT
    end
  when RBS::Types::Optional
    UnionType[from_rbs_type(return_type.type, self_type, extra_vars), NIL]
  when RBS::Types::Alias
    case return_type.name.name
    when :int
      INTEGER
    when :boolish
      BOOLEAN
    when :string
      STRING
    else
      # TODO: ???
      OBJECT
    end
  when RBS::Types::Interface
    # unimplemented
    OBJECT
  when RBS::Types::ClassInstance
    klass = return_type.name.to_namespace.path.reduce(Object) { _1.const_get _2 }
    if return_type.args
      args = return_type.args.map { from_rbs_type _1, self_type, extra_vars }
      names = rbs_builder.build_singleton(return_type.name).type_params
      params = names.map.with_index { [_1, args[_2] || OBJECT] }.to_h
    end
    InstanceType.new klass, params || {}
  else
    OBJECT
  end
end

def self.method_return_bottom?(method)
  method.type.return_type.is_a? RBS::Types::Bases::Bottom
end

def self.match_free_variables(vars, types, values)
  accumulator = {}
  types.zip values do |t, v|
    _match_free_variable(vars, t, v, accumulator) if v
  end
  accumulator.transform_values { UnionType[*_1] }
end

def self._match_free_variable(vars, rbs_type, value, accumulator)
  case [rbs_type, value]
  in [RBS::Types::Variable,]
    (accumulator[rbs_type.name] ||= []) << value if vars.include? rbs_type.name
  in [RBS::Types::ClassInstance, InstanceType]
    names = rbs_builder.build_singleton(rbs_type.name).type_params
    names.zip(rbs_type.args).each do |name, arg|
      v = value.params[name]
      _match_free_variable vars, arg, v, accumulator if v
    end
  in [RBS::Types::Tuple, InstanceType] if value.klass == Array
    v = value.params[:Elem]
    rbs_type.types.each do |t|
      _match_free_variable vars, t, v, accumulator
    end
  in [RBS::Types::Record, InstanceType] if value.klass == Hash
    # TODO
  in [RBS::Types::Interface,]
    definition = rbs_builder.build_interface rbs_type.name
    convert = {}
    definition.type_params.zip(rbs_type.args).each do |from, arg|
      convert[from] = arg.name if arg.is_a? RBS::Types::Variable
    end
    return if convert.empty?
    ac = {}
    definition.methods.each do |method_name, method|
      return_type = method_return_type value, method_name
      method.defs.each do |method_def|
        interface_return_type = method_def.type.type.return_type
        _match_free_variable convert, interface_return_type, return_type, ac
      end
    end
    convert.each do |from, to|
      values = ac[from]
      (accumulator[to] ||= []).concat values if values
    end
  else
  end