How does Pattern Matching in Scala overcome duplication that switch case causes?
design-patterns, oop, scala
Solution
It's the matter of the difference between objects and data structures.
If you are dealing with objects use the subtype polymorphism - adding new types doesn't require recompilation, retesting or redeployment of the existing ones, whereas adding a new algorithm (a method on the interface, which is at the top of the hierarchy) does.
If you are dealing with data structures use patter matching - adding new algorithms doesn't require recompilation, retesting or redeployment of the existing ones, whereas adding a new type does.
Read more about it here.
Problem
NOTE: I am asking this question out of inquisitiveness and not questioning the importance of a language feature. Looks to be a great feature introduced to people from imperative world of programming. I am new to Scala and still trying to figure out where all, do its massive sets of constructs fit in and can be leveraged. Pattern matching can definitely do stuff 100 x better than the switch case. but still, it is a case construct over which we use to prefer polymorphism since the time OOP came out. So in short what I am finding difficult to understand is, If switch case encourages duplication and we better write case related code into respective classes then How does Scala's pattern matching overcome this ? We can still have classes or generic classes for various cases and again leverage polymorphism to our need.