3 ms·

As I'm self taught I lean towards the engineering side of software development, should I do a CS crash course before tackling Scala? Any advice on the best CS b

• DanielRibeiro 15y ago
  If you can use the map function from collections and if you understand why function with one argument has the following signature[1]: Function1 [-T1, +R] Then you should be fine [1] Explanation here: http://stackoverflow.com/questions/5277526/real-world-examples-of-co-and-contravariance-in-scala/5279656#5279656 http://stackoverflow.com/questions/5277526/real-world-exampl...
  • calebmpeterson 15y ago
    Covariance I was good with, but contravariance didn't click until I read that SO post. Thank you.
  • shadowfiend 15y ago
    Not even. To date, while I've learned about and understand contravariance and covariance, I haven't really needed to distinguish between the two in code I've written. I also haven't really needed to distinguish between them in code I'm writing. The thing about type signatures is that if they're set up properly, you rarely have to think about them. Only when your assumption and the reality of a type system disagree do you have to look up why that's happening. And then you can look up covariance and contravariance is necessary. But then, that's just the learning approach that works for me. Call it `Just In Time learning or `Agile learning'. `Learn learning', even...