principles:invariant_avoidance_principle
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| principles:invariant_avoidance_principle [2013-03-07 17:57] – description, rationale, improved example 4 christian | principles:invariant_avoidance_principle [2021-09-02 12:37] – old revision restored (2021-05-11 21:58) 65.21.179.175 | ||
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| So it is better to store just one representation (e.g. the real and imaginary values) and if the other representation is needed (in this case the polar form), it can be computed. This can also be done transparently in the getter method. | So it is better to store just one representation (e.g. the real and imaginary values) and if the other representation is needed (in this case the polar form), it can be computed. This can also be done transparently in the getter method. | ||
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| + | ==== Example 5: Caching ==== | ||
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| + | All forms of caching and redundancy are typical violations of IAP. They are done in order to increase performance. But there is always the disadvantage that all copies have to be kept in sync as there is the invariant that the data may not be inconsistent throughout the copies. There are forms of caching where temporary inconsistencies are tolerated. This is slightly better in terms of IAP but nevertheless there are these consistency constraints and there is the danger of violating them, so to some degree the disadvantage is always there. | ||
principles/invariant_avoidance_principle.txt · Last modified: 2021-10-18 21:53 by christian