POSA Vol.1 EP1, Architecture's architecture
今天随意翻看了下POSA vol1 chapter 1, 这章并没有什么具体讲述patterns, 但仍有几点论述还不错, 当然最主要的是抽象与总起:
1. Each pattern is a three-part rule, which expresses a relation between a certain context, a problem(forces), and a solution
2. A pattern for software architecture describes a particular recurring design problem that arises in specific design contexts, and presents a well-proven generic scheme for its solution. The solution scheme is specified by describing its constituent components, their responsibilities
and relationships, and the ways in which they collaborate.
3. Each pattern depends on the smaller patterns it contains and on the larger patterns in which it is contained.
还有一点主要的是把patterns分了3大类:
- An architectural pattern expresses a fundamental structural organizationschema for software systems. It provides a set of predefined
subsystems, specifies their responsibilities, and includes rules and guidelines for organizing the relationships between them.
- A design pattern provides a scheme for refining the subsystems or components of a software system, or the relationships between them.
It describes a commonly-recumng structure of communicating components that solves a general design problem within a particular context.
- An idiom is a low-level pattern specific to a programming language. An idiom describes how to implement particular aspects of components or the relationships between them using the features of the given language.
- Relation:
Architectural patterns can be used at the beginning of coarse-grained design, design patterns during the whole design phase, and idioms during the implementation phase.
一个不贴切的比拟 - 与建筑中的火车站设计:
- AP, 总体设计, 蓝图, 最高抽象. 包括需要有侯车室, 列车道, 大厅等等独立的组件, 以及他们之间的关系(大厅后面是车道?).
- DP, 单组件的具体设计，比如大厅的通用实现方式(中间电子板，2边是楼梯，5层楼?).
- IP, 具体施工材料, 工具等等.
关于风格设计(中式, 哥特, 俄罗斯尖顶), 感觉并不好归类. 其实在以前建筑设计过程中可能并不需要考虑风格问题, 因为在网络没有普及的情况下迥异的建筑风格应该在某地是不存在的(或则极少), 大家的风格基本如出一辙. AP是一种抽象, 所以明显不可能容纳特化的风格. 个人认为UI设计在哪, 风格就应该在那.
