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Generation gap (pattern)

From Wikipedia, the free encyclopedia

Generation gap is a software design pattern documented by John Vlissides that treats automatically generated code differently than code that was written by a developer. Modifications should not be made to generated code, as they would be overwritten if the code generation process was ever re-run, such as during recompilation.[1] Vlissides proposed creating a subclass of the generated code which contains the desired modification.[2] This might be considered an example of the template method pattern.

Modern languages[edit]

Modern byte-code language like Java were in their early stages when Vlissides developed his ideas. In a language like Java or C#, this pattern may be followed by generating an interface, which is a completely abstract class. The developer would then hand-modify a concrete implementation of the generated interface.


  1. ^ Fowler, Martin. "Generation Gap". martinfowler.com/. Retrieved 9 August 2014.
  2. ^ Vlissides, John (1998-06-22). Pattern Hatching: Design Patterns Applied. Addison-Wesley Professional. pp. 85–101. ISBN 978-0201432930.