kyouko-taiga

Generic programming with type classes

Generic programming is a discipline that encourages the construction of abstractions and the reuse of software component without loss of efficiency. Subtyping through inheritance can be adversary to this goal because it encourages type erasure, promising that efficiency is maintained thanks to dynamic dispatch. Sadly, this promise gets broken when generic data structures and algorithms depend on more than one generic receiver. In those instances, one must resort to generic parameters to preserve type information, introducing expensive annotation costs. This short article examine this problem and then discusses how type classes, an alternative approach to practice generic programming, can address many of the issues presented by subtyping through inheritance.

Disclaimer:

bishabosha

//> using scala "3.3.0"

import scala.util.boundary, boundary.break

object Loops:

  type ExitToken = Unit { type Exit }
  type ContinueToken = Unit { type Continue }

  type Exit = boundary.Label[ExitToken]

djspiewak

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

amaalali

bin/

# Scala/SBT specific
project/
target/
build/

# Scala-Cli build folder
.scala-build/

francescofrontera

import shapeless._, shapeless.ops.hlist._, shapeless.labelled.FieldType

trait Op[A] extends DepFn1[A]

trait LowPriority {
  implicit def identity[A]: Op.Aux[A, A] = Op.createInstance(i => i)
}

object Op extends LowPriority {
  type Aux[A, OUT0] = Op[A] { type Out = OUT0 }

olets

Instructions for installing zsh plugins, for a variety of plugin managers

• antibody: Add <owner>/<repo> to your plugins file. If you use static loading update the sh.

• Antigen: Add antigen bundle <owner>/<repo> to your .zshrc.

• Oh-My-Zsh:

  • Clone to OMZ's plugins' directory:

jdegoes

package fpmax

import scala.util.Try
import scala.io.StdIn.readLine

object App0 {
  def main: Unit = {
    println("What is your name?")

    val name = readLine()

lregnier

Scala with Style (by Martin Odersky)

This is a summary of the guidelines presented by Martin Odersky during his talk Scala with Style.

Table of Contents

• Guidelines
  • 1. Keep it simple
  • 2. Don't pack too much in one expression
  • 3. Prefer Functional
• 4. But don't diabolize local state

lattner

Swift Concurrency Manifesto

Author: Chris Lattner

Chinese Translation by Jason Yu

Contents

• Introduction
• Overall Vision

RobertTalbert

MTH 325 Learning Targets

Proof

• P.1: I can set up a framework of assumptions and conclusions for proofs using direct proof, proof by contraposition, and proof by contradiction.
• P.2: I can identify the predicate being used in a proof by mathematical induction and use it to set up a framework of assumptions and conclusions for an induction proof.
• P.3: I can identify the parts of a proof, including the technique used and the assumptions being made.
• P.4: I can perform a critical analysis of a written proof and provide a detailed explanation of the steps used in the proof.

Graphs