总结
- Complexity is incremental: you have to sweat the small stuff (see p. 11).
- Working code isn’t enough (see p. 14).
- Make continual small investments to improve system design (see p. 15).
- Modules should be deep (see p. 22)
- Interfaces should be designed to make the most common usage as simple as possible (see p. 27).
- It’s more important for a module to have a simple interface than a simple implementation (see pp. 55, 71).
- General-purpose modules are deeper (see p. 39).
- Separate general-purpose and special-purpose code (see p. 62).
- Different layers should have different abstractions (see p. 45).
- Pull complexity downward (see p. 55).
- Define errors (and special cases) out of existence (see p. 79).
- Design it twice (see p. 91).
- Comments should describe things that are not obvious from the code (see p. 101).
- Software should be designed for ease of reading, not ease of writing (see p. 149).
- The increments of software development should be abstractions, not features (see p. 154).
- Shallow Module: the interface for a class or method isn’t much simpler than its implementation (see pp. 25, 110).
- Information Leakage: a design decision is reflected in multiple modules (see p. 31).
- Temporal Decomposition: the code structure is based on the order in which operations are executed, not on information hiding (see p. 32).
- Overexposure: An API forces callers to be aware of rarely used features in order to use commonly used features (see p. 36).
- Pass-Through Method: a method does almost nothing except pass its arguments to another method with a similar signature (see p. 46).
- Repetition: a nontrivial piece of code is repeated over and over (see p. 62).
- Conjoined Methods: two methods have so many dependencies that its hard to understand the implementation of one without understanding the implementation of the other (see p. 72).
- Comment Repeats Code: all of the information in a comment is immediately obvious from the code next to the comment (see p. 104).
- Implementation Documentation Contaminates Interface: an interface comment describes implementation details not needed by users of the thing being documented (see p. 114).
- Vague Name: the name of a variable or method is so imprecise that it doesn’t convey much useful information (see p. 123).
- Hard to Pick Name: it is difficult to come up with a precise and intuitive name for an entity (see p. 125).
- Hard to Describe: in order to be complete, the documentation for a variable or method must be long. (see p. 131).
- Nonobvious Code: the behavior or meaning of a piece of code cannot be understood easily. (see p. 148).