What is design_patterns?

Design Patterns Illustrated is a free, open-source book that explains software design patterns using a combination of diagrams and code. It's written in Chinese and aimed at developers who want to understand common programming templates, see how they work visually, and then implement them in practice. The project covers the classic "Gang of Four" design patterns, organized into three categories: creational patterns (how objects get created), structural patterns (how classes and objects are composed), and behavioral patterns (how objects communicate with each other). Each pattern gets a structural diagram showing the relationships between the pieces, and a sequence diagram showing the step-by-step interaction when the pattern runs. The code examples are in C++ and were compiled with an older version of GCC, so they're straightforward rather than cutting-edge. The intended audience is developers who can read code but haven't formally studied design patterns, or who have read about them but can't actually apply them at work. The author frames the learning goal in three stages: draw the patterns from memory, implement them in code, and use them flexibly in real projects. The emphasis on diagrams reflects the idea that seeing the structure visually makes the patterns stick better than reading prose alone. One thing worth noting is that this is a learning resource, not a library or tool you plug into a project. The example code is meant to be read and typed out, not imported. The diagrams were created in Enterprise Architect (a UML modeling tool), and the book itself is built with Sphinx, a documentation generator, so you can browse it online or build the HTML locally. If you're not a C++ developer, the diagrams and explanations still apply, but you'd need to translate the code examples into your language of choice.