Boston Haskell Lightning talks - Dec. 2014

Edward Kmett - Encapsulation vs. Code Reuse

Boston Haskell lightning talks: Rust, Phantoms, ATS, Freezing, Music, and Code reuse Our December meetup's lightning talks are up on youtube. The individual breakdown: Darius Jahandarie - Rust for Haskellers Elliot Stern - Fun with Phantoms William Blair - Debugging with types in ATS Kenny Foner - Ice, Ice, Data (Freezing mutable data structures with Midas) Tom Titchener - Building a real simple music generator to parameterize canons Edward Kmett - Encapsulation vs. Code Reuse Enjoy!

> I actually dislike Types modules, or at least I don't see the point in separating type definitions from the functions that use them. As I said above, I do it because it seems like almost every time I don't do it, I end up having cyclic dependency problems with those modules somewhere down the road. Yes, I know it's sometimes possible to get GHC to build cyclic dependencies, but that never seemed like a good solution to me. And frankly, cyclic dependencies seem like a symptom of poor organization. Maybe my experience is too limited to a narrow application domain, but this seems like a pretty fundamental emergent property of Haskell. > In fact, if you use a separate Types module, you are…

I did a mini-rant on this topic a couple of years back: link to this video

Yes, also see Edward Kmett - Encapsulation vs. Code Reuse.

Strongly disagree. I reject the idea of interfaces. They are _always_ either too big or too small. It took us two decades to drive this obsession with "programming against an interface" out of people, so please don't try to put it back. It just obfuscates programs without any benefit. The running example of data structures like stacks is particularly hilarious because it falls apart instantly. There is only one correct implementation of a stack because as you point out the time complexity as well as the effects are very important. I remember how refreshing it was learning about Haskell's `containers`. A type and useful functions using it. No nonsense. Also see Kmett's classical rant [Enc…