设计模式培训教材

                As an element of language , a pattern is an instruction , which shows how this spatial configuration can be used , over and over again to resolve the given system of forces , wherever the context makes it relevant .                The pattern is , in short , at the same time a thing , which happens in the world , and the rule which tells us how to create that thing , and when we must create it . It’s both a process and a thing , both a description of a thing which is alive , and a description of t ...