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principles:rule_of_explicitness [2013-03-03 11:02] – relations, strategies christianprinciples:rule_of_explicitness [2021-10-14 21:54] – old revision restored (2021-09-02 12:38) 46.161.27.210
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 ===== Context ===== ===== Context =====
 /* fill in contexts here: */ /* fill in contexts here: */
-  * [[contexts:Object-Oriented Design]] +  * [[contexts:Object-Oriented Design]] 
 +  * [[contexts:API Design]]
  
  
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 ===== Description ===== ===== Description =====
  
 +Solutions often differ in the level of explicitness. A feature can be implemented explicitly or it can be a side-effect of the implementation of another feature or a more general functionality. The same applies to module communication. A module can invoke another module directly or there can be various forms of indirections like events or observers.
  
 +RoE states that explicit solutions are better than implicit ones. Indirection, side-effects, configuration files, implicit conversions, etc. should be avoided.
 ===== Rationale ===== ===== Rationale =====
  
 +If something is realized explicitly, it is easier to understand. Implicit solutions require the developer to have a deeper understanding of the module as it is necessary to "read between the lines". Implicit solutions also tend to be more complex. So explicit solutions are assumed to be less error-prone and easier to maintain.
  
 ===== Strategies ===== ===== Strategies =====
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     * In Python and other languages that allow this use named parameters.     * In Python and other languages that allow this use named parameters.
     * Avoid long parameter lists and use objects with explicit attribute assignments instead. (see [[Option-Operand Separation]])     * Avoid long parameter lists and use objects with explicit attribute assignments instead. (see [[Option-Operand Separation]])
 +    * Use parameter types that explicitly state what the input is. Rather use specific types for parameters like customers, articles, URLs, colors, money, etc. instead of using strings or integers for these values (see [[anti-patterns:primitive obsession]]).
   * Avoid implicit type conversions.    * Avoid implicit type conversions. 
     * In C# do not to specify implicit cast operations      * In C# do not to specify implicit cast operations 
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   * [[Generalization Principle]] (GP): RoE often results in specific solutions. Generality often requires stating something implicitly.   * [[Generalization Principle]] (GP): RoE often results in specific solutions. Generality often requires stating something implicitly.
   * [[Low Coupling]] (LC): Direct communication typically has the disadvantage of a higher coupling. Indirection reduces coupling but creates implicit/indirect communication paths.    * [[Low Coupling]] (LC): Direct communication typically has the disadvantage of a higher coupling. Indirection reduces coupling but creates implicit/indirect communication paths. 
 +
  
 ==== Complementary Principles ==== ==== Complementary Principles ====
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   * [[Keep It Simple Stupid]] (KISS): Explicit solutions are often also simpler.   * [[Keep It Simple Stupid]] (KISS): Explicit solutions are often also simpler.
   * [[Murphy's Law]] (ML):The typical reason for RoE is to avoid unnecessarily complicated solutions and possibilities for defects. Don't loose that goal out of sight.   * [[Murphy's Law]] (ML):The typical reason for RoE is to avoid unnecessarily complicated solutions and possibilities for defects. Don't loose that goal out of sight.
 +  * [[Model Principle]] (MP): RoE states that [[anti-patterns:primitive obsession]] shall be avoided. Instead more specific types should be used in parameter lists. MP makes this even clearer: In object-orientation objects instead of plain integers or strings are used.
 +
  
 ==== Principle Collections ==== ==== Principle Collections ====
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-===== Example =====+===== Examples =====
  
  
principles/rule_of_explicitness.txt · Last modified: 2021-10-18 22:06 by christian