Abstraction inversion

In computer programming, abstraction inversion is an anti-pattern arising when users of a construct need functions implemented within it but not exposed by its interface. The result is that the users re-implement the required functions in terms of the interface, which in its turn uses the internal implementation of the same functions. This may result in implementing lower-level features in terms of higher-level ones, thus the term 'abstraction inversion'.

Possible ill-effects are:

• The user of such a re-implemented function may seriously underestimate its running-costs.
• The user of the construct is forced to obscure their implementation with complex mechanical details.
• Many users attempt to solve the same problem, increasing the risk of error.