multiple_arity_function_definitions.rb

@lookup = {}

def fn name, *arities, callback
  @lookup["#{name} #{arities}"] = callback
end

def lookup_fn_by_arities name, *arities
  @lookup["#{name} #{arities}"]
end

a = 1
b = 2
c = 3

fn :foo, 1, 2, 3, -> (*local_arities) {
  puts "foo 1"
  puts local_arities
}

fn :foo, a==1, 1, b==2, 2, c==4, -> (*local_arities) {
  puts "foo 2"
  puts local_arities
}

lookup_fn_by_arities(:foo, 1, 2, 3).call(1,2,3)
lookup_fn_by_arities(:foo, true, 1, true, 2, false).call(4,5,6)