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principles:principle_of_separate_understandability

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principles:principle_of_separate_understandability [2013-10-07 14:26]
christian several minor improvements
principles:principle_of_separate_understandability [2014-07-02 19:42] (current)
christian SLA
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   * You have to find the implementation and jump there (modern IDEs help here but it takes time nevertheless)   * You have to find the implementation and jump there (modern IDEs help here but it takes time nevertheless)
   * While doing so, you have to memorize the call and the context of the call. If implementation and call are not colocated (which is preferable but not always possible) you won't see the call anymore so you have to memorize it.   * While doing so, you have to memorize the call and the context of the call. If implementation and call are not colocated (which is preferable but not always possible) you won't see the call anymore so you have to memorize it.
-  * Then you have to read the code and mentally inline it. +  * Then you have to read the code and [[glossary:​mental inlining|mentally inline]] it. 
-  * If you could not memoroze ​everything, you might have to jump back and forth to do the job.+  * If you could not memorize ​everything, you might have to jump back and forth to do the job.
   * After you did all that you have to jump back and continue reading the method with the call you just mentally inlined.   * After you did all that you have to jump back and continue reading the method with the call you just mentally inlined.
  
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   * [[Tell, don't Ask/​Information Expert]] (TdA/IE): At its heart PSU is about responsibility assignment. When a module is not separately understandable,​ this means that a responsibility is scattered across several modules. TdA/IE gives another aspect of responsibility assignment.   * [[Tell, don't Ask/​Information Expert]] (TdA/IE): At its heart PSU is about responsibility assignment. When a module is not separately understandable,​ this means that a responsibility is scattered across several modules. TdA/IE gives another aspect of responsibility assignment.
   * [[Low Coupling]] (LC): Not adhering to PSU means that responsibilities are scattered across several modules. This typically also means increased coupling.   * [[Low Coupling]] (LC): Not adhering to PSU means that responsibilities are scattered across several modules. This typically also means increased coupling.
 +  * [[Single Level of Abstraction]] (SLA): The purpose of PSU is to avoid [[glossary:​mental inlining]]. SLA on the other hand is about the avoiding the opposite: [[glossary:​mental grouping]].
  
 ==== Principle Collections ==== ==== Principle Collections ====
principles/principle_of_separate_understandability.txt · Last modified: 2014-07-02 19:42 by christian