symbols - Pass Ruby object's instance variables to another class's initializer as a map -

i'm using xml-mapping gem read xml, , want feed mapping objects initializers existing domain classes. given xml like:

<foo bar="baz"><qux>quux</qux></foo> 

i object like:

#<foo @bar="baz", @qux="quux"> 

i want feed domain class like:

class myfoo   def initialize(bar:, qux:)     # ... etc.   end end 

(note in myfoo attributes read-only, , there's validation , transformation goes on in initializer, it's not matter of copying instance variables 1 other.)

i tried transforming instance variables map, thus:

foo.instance_variables.map { |name| [name, foo.instance_variable_get(name)] }.to_h 

which produces:

{ :@bar->"baz", :@qux->"quux" } 

this almost need myfoo initializer, not quite -- need is

{ :bar->"baz", :qux->"quux" } 

is there way transform instance variable names symbols without @-sign?

alternatively, there easier way "initialize attributes in object"?

andrey's comment works fine, dislike relying on instance variables directly. suggest adding custom to_h method foo class. tie in xml-mapping following:

class foo   # ...   def self.__fields__     @__fields__ ||= all_xml_mapping_nodes.map { |r| r.instance_variable_get(:@attrname) }   end    def to_h     self.class.__fields__.each_with_object({}) |field, acc|       acc[field] = send(field)     end   end   end 

then call myfoo.new(foo.to_h).

edit

as extension xml::mapping:

module xmlmappingextensions    def self.included(base)     base.extend(classmethods)   end    module classmethods     def __fields__       @__fields__ ||= all_xml_mapping_nodes.map { |r| r.instance_variable_get(:@attrname) }     end   end    def to_h     self.class.__fields__.each_with_object({}) |field, acc|       acc[field] = send(field)     end   end    end 

and either include xmlmappingextensions in foo class, or:

module xml::mapping   # note: may break xml::mapping if using method   # , there more graceful way   # tried , seems work fine...   def self.included(base)     base.send(:include, xmlmappingextensions)   end end 

after have loaded xml::mapping , before have loaded foo class.