Alexey Shuksto seigert

Understanding Comparative Benchmarks

I'm going to do something that I don't normally do, which is to say I'm going to talk about comparative benchmarks. In general, I try to confine performance discussion to absolute metrics as much as possible, or comparisons to other well-defined neutral reference points. This is precisely why Cats Effect's readme mentions a comparison to a fixed thread pool, rather doing comparisons with other asynchronous runtimes like Akka or ZIO. Comparisons in general devolve very quickly into emotional marketing.

But, just once, today we're going to talk about the emotional marketing. In particular, we're going to look at Cats Effect 3 and ZIO 2. Now, for context, as of this writing ZIO 2 has released their first milestone; they have not released a final 2.0 version. This implies straight off the bat that we're comparing apples to oranges a bit, since Cats Effect 3 has been out and in production for months. However, there has been a post going around which cites various compar

Brew Bundle Brewfile Tips

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Parallels between `map` and similar functions

map          :: F[A] => (A =>     B)   => F[B]
flatMap      :: F[A] => (A =>   F[B])  => F[B]
traverse     :: G[A] => (A =>   F[B])  => F[G[B]]
flatTraverse :: G[A] => (A => F[G[B]]) => F[G[B]]
traverse_    :: F[A] => (A =>   F[B])  => F[Unit]

Thread Pools

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

CPU-bound
Blocking IO
Non-blocking IO polling

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

Commit Message Guidelines

Short (72 chars or less) summary

More detailed explanatory text. Wrap it to 72 characters. The blank
line separating the summary from the body is critical (unless you omit
the body entirely).

Write your commit message in the imperative: "Fix bug" and not "Fixed
bug" or "Fixes bug." This convention matches up with commit messages

Laws

A law is a group of two or more expressions which are required to be the same. The expressions will usually involve one or more typed holes ("inputs") which vary.

Some examples:

x.map(id) === x

	\|----------------------------------------------------------------------------------------\|--------------------\|
	\| Object Header (64 bits) \| State \|
	\|-------------------------------------------------------\|--------------------------------\|--------------------\|
	\| Mark Word (32 bits) \| Klass Word (32 bits) \| \|
	\|-------------------------------------------------------\|--------------------------------\|--------------------\|
	\| identity_hashcode:25 \| age:4 \| biased_lock:1 \| lock:2 \| OOP to metadata object \| Normal \|
	\|-------------------------------------------------------\|--------------------------------\|--------------------\|
	\| thread:23 \| epoch:2 \| age:4 \| biased_lock:1 \| lock:2 \| OOP to metadata object \| Biased \|
	\|-------------------------------------------------------\|--------------------------------\|--------------------\|
	\|

	"\e[1~": beginning-of-line
	"\e[4~": end-of-line
	"\e[5~": history-search-backward
	"\e[6~": history-search-forward
	"\e[3~": delete-char
	"\e[2~": quoted-insert
	"\e[5C": forward-word
	"\e[5D": backward-word
	"\e\e[C": forward-word
	"\e\e[D": backward-word