kubukoz

Why you prefer cats instead of zio? TF? It’s looks like zio ecosystem more widely and zio 2.0 has better performance What do you think?

Great question!

Performance-wise, it really depends on what you're doing. The problem with benchmarks (including the ones posted for ZIO and Cats Effect) is that they apply only to abstract situations, which are often nothing like what you see in real applications. A great write-up on this problem by Daniel Spiewak here, he wrote it better than I ever could: https://gist.github.com/djspiewak/f4cfc08e0827088f17032e0e9099d292

Also, this is not an app meant for production - I don't care that much about performance under load because there will be no load. And individual operations will often be bounded by I/O anyway, so the efficiency of the underlying runtime is likely not going to make a noticeable difference in use. Then again, both the client and server are JVM apps, so even the start-up penalty of the client will slow us down than picking even the least efficient e

djspiewak

Fibers

Fibers are an abstraction over sequential computation, similar to threads but at a higher level. There are two ways to think about this model: by example, and abstractly from first principles. We'll start with the example.

(credit here is very much due to Fabio Labella, who's incredible Scala World talk describes these ideas far better than I can)

Callback Sequentialization

Consider the following three functions

mGBUfLn9

I was drawn to programming, science, technology and science fiction
ever since I was a little kid. I can't say it's because I wanted to
make the world a better place. Not really. I was simply drawn to it
because I was drawn to it. Writing programs was fun. Figuring out how
nature works was fascinating. Science fiction felt like a grand
adventure.

Then I started a software company and poured every ounce of energy
into it. It failed. That hurt, but that part is ok. I made a lot of
mistakes and learned from them. This experience made me much, much

martinsson

%default total

-- Proofs that a value is divisible my 3 and 5 respectively
IsFizz : (k : Nat) -> Type
IsFizz k = (modNatNZ k 3 SIsNotZ = 0)

IsBuzz : Nat -> Type
IsBuzz k = (modNatNZ k 5 SIsNotZ = 0)

-- The type Fizzbuzz, one can only construct an instance of Fizz if one can provide

djspiewak

Thread Pools

Thread pools on the JVM should usually be divided into the following three categories:

1. CPU-bound
2. Blocking IO
3. Non-blocking IO polling

Each of these categories has a different optimal configuration and usage pattern.

psayre23

Below are the Big O performance of common functions of different Java Collections.


List                 | Add  | Remove | Get  | Contains | Next | Data Structure
---------------------|------|--------|------|----------|------|---------------
ArrayList            | O(1) |  O(n)  | O(1) |   O(n)   | O(1) | Array
LinkedList           | O(1) |  O(1)  | O(n) |   O(n)   | O(1) | Linked List
CopyOnWriteArrayList | O(n) |  O(n)  | O(1) |   O(n)   | O(1) | Array