|
A loop-switch sequence (also known as the for-case paradigm〔(The FOR-CASE paradigm ) and (Switched on Loops ) at The Daily WTF〕 or Anti-Duff's Device) is a programming antipattern where a clear set of steps is implemented as a switch-within-a-loop. The loop-switch sequence is a specific derivative of spaghetti code. It is not necessarily an antipattern to use a switch statement within a loop—it is only considered incorrect when used to model a known sequence of steps. The most common example of the correct use of a switch within a loop is an inversion of control such as an event handler. In event handler loops, the sequence of events is not known at compile-time, so the repeated switch is both necessary and correct (see event-driven programming, event loop and event-driven finite state machine). Note that this is not a performance antipattern, though it may lead to an inconsequential performance penalty due to the lack of an unrolled loop. Rather, this is a clarity antipattern, as in any non-trivial example, it is much more difficult to decipher the intent and actual function of the code than the more straightforward refactored solution. ==Example== An event-driven solution would implement a listener interface: String key = null; String value = null; List int column = 0; public void addToken(token) } But without the listener, it becomes an example of the antipattern: // parse a key, a value, then three parameters String key = null; String value = null; List for (int i = 0; i < 5; i++) And here is the refactored solution: // parse a key and value String key = stream.parse(); String value = stream.parse(); // parse 3 parameters List for (int i = 2; i < 5; i++) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Loop-switch sequence」の詳細全文を読む スポンサード リンク
|