class Module
def find_const(const_name)
if const_name[0..1] == '::'
Object.find_const(const_name[2..-1])
else
nested_const_lookup(const_name)
end
end
private
# Doesn't do any caching since constants can change with remove_const
def nested_const_lookup(const_name)
constants = [ Object ]
unless self == Object
self.name.split('::').each do |part|
constants.unshift(constants.first.const_get(part))
end
end
parts = const_name.split('::')
# from most to least specific constant, use each as a base and try
# to find a constant with the name const_name within them
constants.each do |const|
# return the nested constant if available
return const if parts.all? do |part|
const = const.const_defined?(part) ? const.const_get(part) : nil
end
end
# if we get this far then the nested constant was not found
raise NameError
end
end # class Module
