module T::Private::Abstract::Data

We need to associate data with abstract modules. We could add instance methods to them that access ivars, but those methods will unnecessarily pollute the module namespace, and they'd have access to other private state and methods that they don't actually need. We also need to associate data with arbitrary classes/modules that implement abstract mixins, where we don't control the interface at all. So, we access data via these `get` and `set` methods.

Using instance_variable_get/set here is gross, but the alternative is to use a hash keyed on `mod`, and we can't trust that arbitrary modules can be added to those, because there are lurky modules that override the `hash` method with something completely broken.

Public Class Methods

get(mod, key) click to toggle source
# File lib/types/private/abstract/data.rb, line 14
def self.get(mod, key)
  mod.instance_variable_get("@opus_abstract__#{key}")
end
key?(mod, key) click to toggle source
# File lib/types/private/abstract/data.rb, line 22
def self.key?(mod, key)
  mod.instance_variable_defined?("@opus_abstract__#{key}")
end
set(mod, key, value) click to toggle source
# File lib/types/private/abstract/data.rb, line 18
def self.set(mod, key, value)
  mod.instance_variable_set("@opus_abstract__#{key}", value)
end
set_default(mod, key, default) click to toggle source

Works like `setdefault` in Python. If key has already been set, return its value. If not, insert `key` with a value of `default` and return `default`.

# File lib/types/private/abstract/data.rb, line 28
def self.set_default(mod, key, default)
  if self.key?(mod, key)
    self.get(mod, key)
  else
    self.set(mod, key, default)
    default
  end
end