class IDL::AST::Module

def redefine(node, params)
  case node
  when IDL::AST::Include
    if node.enclosure == self
      return node
    else
      _inc = IDL::AST::Include.new(node.name, self, params)
      _inc.annotations.concat(params[:annotations])
      @children << _inc
      return _inc
    end
  when IDL::AST::Module
    # Module reopening
    _anchor = node.has_anchor? ? node.anchor : node
    _anchor.annotations.concat(params.delete(:annotations))
    _last = _anchor.find_last
    _params = params.merge({ anchor: _anchor, prefix: node.prefix })
    _next = IDL::AST::Module.new(node.name, self, _params)
    _last.set_next(_next)
    @children << _next
    return _next
  when IDL::AST::Interface
    node.annotations.concat(params[:annotations])
    # in case of a forward declaration in the same module ignore it since a previous declaration already exists
    if params[:forward]
      return node if node.enclosure == self
      # forward declaration in different scope (other module section in same file or other file)
    elsif node.is_defined?
      # multiple full declarations are illegal
      raise "#{node.typename} \"#{node.name}\" is already defined."
    end
    if (node.is_abstract? != params[:abstract]) || (node.is_local? != params[:local]) || (node.is_pseudo? != params[:pseudo])
      raise "\"attributes are not the same: \"#{node.name}\"."
    end
    _intf = IDL::AST::Interface.new(node.name, self, params)
    _intf.annotations.concat(node.annotations)
    _intf.prefix = node.prefix
    _intf.instance_variable_set(:@repo_ver, node.instance_variable_get(:@repo_ver))
    _intf.instance_variable_set(:@repo_id, node.instance_variable_get(:@repo_id))
    @children << _intf
    # in case of a full declaration undo the preceding forward introduction and
    # replace by full node
    # (no need to introduce forward declaration since there is a preceding introduction)
    unless params[:forward]
      # replace forward node registration
      node.enclosure.undo_introduction(node)
      introduce(_intf)
    end
    return _intf
  when IDL::AST::Valuetype
    node.annotations.concat(params[:annotations])
    return node if params[:forward]
    if node.is_defined?
      raise "#{node.typename} \"#{node.name}\" is already defined."
    end
    if (node.is_abstract? != params[:abstract])
      raise "\"attributes are not the same: \"#{node.name}\"."
    end
    _new_node = node.class.new(node.name, self, params)
    _new_node.annotations.concat(node.annotations)
    _new_node.prefix = node.prefix
    _new_node.instance_variable_set(:@repo_ver, node.instance_variable_get(:@repo_ver))
    _new_node.instance_variable_set(:@repo_id, node.instance_variable_get(:@repo_id))
    @children << _new_node
    # replace forward node registration
    node.enclosure.undo_introduction(node)
    introduce(_new_node)
    return _new_node
  when IDL::AST::Struct, IDL::AST::Union
    node.annotations.concat(params[:annotations])
    return node if params[:forward]
    if node.is_defined?
      raise "#{node.typename} \"#{node.name}\" is already defined."
    end
    _new_node = node.class.new(node.name, self, params)
    _new_node.annotations.concat(node.annotations)
    _new_node.prefix = node.prefix
    _new_node.instance_variable_set(:@repo_ver, node.instance_variable_get(:@repo_ver))
    _new_node.instance_variable_set(:@repo_id, node.instance_variable_get(:@repo_id))
    node.switchtype = params[:switchtype] if node.is_a?(IDL::AST::Union)
    @children << _new_node
    # replace forward node registration
    node.enclosure.undo_introduction(node)
    introduce(_new_node)
    return _new_node
  end
  raise "#{node.name} is already introduced as #{node.typename} #{node.scoped_name}."
end