In Kotlin, a coroutine can be abandoned by not resuming it. If a coroutine is abandoned while suspending in a try-block with finally, the finally clause will not be executed until the coroutine is collected.
For example, the following Kotlin code
val seqWithFinally = sequence {
try {
yield(Unit)
yield(Unit)
| type USD = number & { readonly __brand: unique symbol } | |
| type EUR = number & { readonly __brand: unique symbol } | |
| type Currency = USD | EUR; | |
| function addCurrency<T extends Currency>(a: T, b: T): T { | |
| return (a + b) as T; | |
| } | |
| addCurrency(5 as USD, 6 as USD); |
Inspired by elizarov/DeepRecursiveFunction.kt.
Normally, when recursively evaluating the depth of a deep tree, it will result in stack overflow error. But, by using async/await, it keeps its stack on the heap, and evaluates correct result without error.
public static class Program
{
| // [dependencies] | |
| // lazy_static = "1.4" | |
| // crossbeam-channel = "0.4" | |
| use crossbeam_channel::{unbounded, SendError, Sender}; | |
| use lazy_static::lazy_static; | |
| use std::thread; | |
| use std::time::Duration; | |
| lazy_static! { |
| import Control.Concurrent | |
| import Control.Concurrent.Async | |
| delayHello n = do | |
| threadDelay (n * 100) | |
| let hello = show n ++ ": Hello World!" | |
| putStrLn hello | |
| delayHello :: Int -> IO () | |
| delayHello n = do |
| /// Warning: the following code is made for experiment. | |
| /// If you cause losses due to the use of this code in production, I am not responsible. | |
| #[derive(PartialEq, Eq, Clone, Debug)] | |
| pub struct List<T = ()>(pub Vec<T>); | |
| #[derive(PartialEq, Eq, Clone, Debug)] | |
| pub struct Id<T = ()>(pub T); | |
| pub trait HKT<T> { | |
| type Actual; |
| // The following task would create a `classpath` directory under the build dir, with a copy of the built jar and links of every jar from classpath. | |
| // You can start the project by `java -classpath "classpath/*" MainClass`. | |
| // This is useful for creating a personal-used script reusing gradle cache. | |
| // This idea is inspired by the pnpm project. | |
| task("linkClasspath") { | |
| val jarTask = tasks.getByName("jar", Jar::class) | |
| dependsOn(jarTask) | |
| doLast { | |
| val targetDir = File(buildDir, "classpath") | |
| if (!targetDir.mkdirs()) { |
Some recommended books for improving as a software developer
Most software books are too language specific and go out of date too quickly. What I find has stayed with me are books about bigger concepts, such as systems thinking and complexity, and also so-called "soft skills" such as management and psychology.
These are all really about developing empathy for other people :)