Content deleted Content added
The LSS happens more often as a result of IOC |
|||
Line 1:
A '''loop-switch sequence'''<ref name="LEVEL ">{{cite web | url=https://levelupcode.wordpress.com/avoid/loop-switch-sequences/ | title=Loop-switch sequences | publisher=LEVEL UP CODE | accessdate=11 April 2016}}</ref> (also known as the '''for-case paradigm'''<ref>[http://thedailywtf.com/Articles/The_FOR-CASE_paradigm.aspx The FOR-CASE paradigm] and [http://thedailywtf.com/Articles/Switched_on_Loops.aspx Switched on Loops] at [[The Daily WTF]]</ref> 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 [[Loop unwinding|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==
| |||