ruby - Getting local variable names defined inside a method from outside the method -

is possible in ruby local variables names defined inside method outside method using metaprogramming?

def foo   var = 100   arr = [1,2] end 

something foo.local_variables.

i need retrieve variable names, not values.

why i'm trying find variable names: have class want dynamically generate setters instance variables initialized in "#initialize".

in order that, inside "initialize", using instance_variables.each |inst_var_name| define_singleton_method(...) ...

this works: each instanced object gets setters singleton methods. however, looking solution read instance variables names outside "initialize" method, in order able use "#define_method" them, , create regular methods , not singleton methods.

you can (re)-parse method , inspect s-expr tree. see below proof of concept. can hold of file method defined using method#source_location , read file. there surely room improvement code should started. functional piece of code , requires ruby parser gem (https://github.com/whitequark/parser).

require 'parser/current' node = parser::currentruby.parse(data.read) # data comes after __end__  def find_definition(node, name)   return node if definition_node?(node, name)   if node.respond_to?(:children)     node.children.find |child|       find_definition(child, name)     end   end end  def definition_node?(node, name)   return false if !node.respond_to?(:type)   node.type == :def && node.children.first == name end  def collect_lvasgn(node)   result = []   return result if !node.respond_to?(:children)    node.children.each |child|     if child.respond_to?(:type) && child.type == :lvasgn       result << child.children.first     else       result += collect_lvasgn(child)     end   end    result end  definition = find_definition(node, :foo) puts collect_lvasgn(definition)  __end__  def foo   var = 100   arr = [1,2]   if     = 3 * var   end end  def bar   var = 200   arr = [3, 4] end 

do mind telling why want find variables?