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monadplus /
Last active Mar 8, 2020
Profiling in Haskell

You'll generally want to look at:

  • heap
  • stack
  • gc profiles

Do not get bogged down in microoptimizations before you've assessed any macro optimizations that are available. IO and the choice of algorithm dominate any low level changes you may make. In the end you have to think hard about your code!

Topos> For example, if i see that a particular pure function is taking a  long time relative to the rest of the code, and that it's Text, and I'm seeing ARR_WORDS rise linearly in the heap, I probably have a thunk-based memory leak. This is knowledge you build up over time.
Icelandjack / Yoneda_II.markdown
Last active May 12, 2020
Yoneda Intuition from Humble Beginnings
View Yoneda_II.markdown

(previous Yoneda blog) (reddit) (twitter)

Yoneda Intuition from Humble Beginnings

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.

jdegoes / fpmax.scala
Created Jul 13, 2018
FP to the Max — Code Examples
View fpmax.scala
package fpmax
import scala.util.Try
object App0 {
def main: Unit = {
println("What is your name?")
val name = readLine()
ChrisChares /
Last active Jul 9, 2019
async/await with ES6 Generators & Promises

async/await with ES6 Generators & Promises

This vanilla ES6 function async allows code to yield (i.e. await) the asynchronous result of any Promise within. The usage is almost identical to ES7's async/await keywords.

async/await control flow is promising because it allows the programmer to reason linearly about complex asynchronous code. It also has the benefit of unifying traditionally disparate synchronous and asynchronous error handling code into one try/catch block.

This is expository code for the purpose of learning ES6. It is not 100% robust. If you want to use this style of code in the real world you might want to explore a well-tested library like co, task.js or use async/await with Babel. Also take a look at the official async/await draft section on desugaring.


  • node.js - 4.3.2+ (maybe earlier with

Applied Functional Programming with Scala - Notes

Copyright © 2016-2018 Fantasyland Institute of Learning. All rights reserved.

1. Mastering Functions

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
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