- The Log-Structured Merge-Tree (LSM-Tree)
- B-Tree vs Log-Structured Merge-Tree
- Modern B-tree techniques
- LSM-based Storage Techniques: A Survey
- B-tree Indexes and CPU Caches by Goetz Graefe and Per-Åke Larson
openssl genrsa -out self-ssl.key
openssl req -new -key self-ssl.key -out self-ssl.csr -config csr.conf
openssl x509 -req -days 365 -in self-ssl.csr -signkey self-ssl.key -out self-ssl.crt -extensions req_ext -extfile csr.conf
Sign from Root CA:
openssl x509 -req -days 365 -extensions req_ext -extfile csr.conf -CA RootCA.crt -CAkey RootCA.key -in self-ssl.csr -out self-ssl.crt
// these aren't _quite_ functional tests, | |
// and should all be compile_fail, | |
// but may be illustrative | |
#[test] | |
fn concurrent_set() { | |
use std::sync::Arc; | |
let x = Arc::new(Cell::new(42)); | |
let x1 = Arc::clone(&x); | |
std::thread::spawn(move || { |
Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.
A function is a mapping from one set, called a domain, to another set, called the codomain. A function associates every element in the domain with exactly one element in the codomain. In Scala, both domain and codomain are types.
val square : Int => Int = x => x * x
Locate the section for your github remote in the .git/config
file. It looks like this:
[remote "origin"]
fetch = +refs/heads/*:refs/remotes/origin/*
url = git@github.com:joyent/node.git
Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/*
to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:
#![warn(rust_2018_idioms)] | |
#[derive(Debug)] | |
pub struct StrSplit<'haystack, D> { | |
remainder: Option<&'haystack str>, | |
delimiter: D, | |
} | |
impl<'haystack, D> StrSplit<'haystack, D> { | |
pub fn new(haystack: &'haystack str, delimiter: D) -> Self { |
(previous Yoneda blog) (reddit) (twitter)
Let's explore the Yoneda lemma. You don't need to be an advanced Haskeller to understand this. In fact I claim you will understand the first section fine if you're comfortable with map
/fmap
and id
.
I am not out to motivate it, but we will explore Yoneda at the level of terms and at the level of types.
Think of all the arguments you've heard as to why static typing is desirable — every single one of those arguments applies equally well to using types to represent error conditions.
An odd thing I’ve observed about the Scala community is how many of its members believe that a) a language with a sophisticated static type system is very valuable; and b) that using types for error handling is basically a waste of time. If static types are useful—and if you like Scala, presumably you think they are—then using them to represent error conditions is also useful.
Here's a little secret of functional programming: errors aren't some special thing that operate under a different set of rules to everything else. Yes, there are a set of common patterns we group under the loose heading "error handling", but fundamentally we're just dealing with more values. Values that can have types associated with them. There's absolutely no reason why the benefits of static ty