⊣˚∆˚⊢ srdjan

Algebraic Effects in JavaScript part 3 - Delimited Continuations

This is the third part of a series about Algebraic Effects and Handlers.

Part 1 : continuations and control transfer
Part 2 : Capturing continuations with Generators
Part 3 : Delimited continuations
Part 4 : Algebraic Effects and handlers

In the preceding parts, we introduced the notions of continuations and control transfer. We saw how to capture the current

Algebraic Effects in JavaScript part 2 - Capturing continuations with Generators

This is the second part of a series about Algebraic Effects and Handlers.

Part 1 : continuations and control transfer
Part 2 : Capturing continuations with Generators
Part 3 : Delimited continuations
Part 4 : Algebraic Effects and handlers

Note: initially I planned a 3-part series, but since the current post on undelimited continuations ended up taking

Algebraic Effects in JavaScript part 1 - continuations and control transfer

This is the first post of a series about Algebraic Effects and Handlers.

There are 2 ways to approach this topic:

Denotational: explain Algebraic Effects in terms of their meaning in mathematics/Category theory
Operational: explain the mechanic of Algebraic Effects by showing how they operate under a chosen runtime environment

Both approaches are valuables and give different insights on the topic. However, not everyone (including me), has the prerequisites to grasp the concepts of Category theory and Abstract Algebra. On the other hand, the operational approach is accessible to a much wider audience of programmers even if it doesn't provide the full picture.

Security Tools for AWS

I often get asked which tools are good to use for securing your AWS infrastructure so I figured I'd write a short listof some useful Security Tools for the AWS Cloud Infrastructure.

This list is not intended be something completely exhaustive, more so provide a good launching pad for someone as they dig into AWS and want to make it secure from the start.

Open Source

This section focuses on tools and services provided by the community and released as open-source.

Note:

When this guide is more complete, the plan is to move it into Prepack documentation.
For now I put it out as a gist to gather initial feedback.

A Gentle Introduction to Prepack (Part 1)

If you're building JavaScript apps, you might already be familiar with some tools that compile JavaScript code to equivalent JavaScript code:

Babel lets you use newer JavaScript language features, and outputs equivalent code that targets older JavaScript engines.

In this tutorial we're going to build a set of parser combinators.

What is a parser combinator?

We'll answer the above question in 2 steps.

What is a parser?
and, what is a parser combinator?

So first question: What is parser?

Answers to Deep Questions about Solidity

The following list of questions was taken from https://www.reddit.com/r/ethereum/comments/72reba/do_you_have_deep_questions_about_solidity_or_the/

An updated summary on the different ways one could have two contracts interact (DELEGATECALL, STATICCALL, libraries, all that stuff) with clear pros/cons for each (gas cost, whether it requires EVM assembly directives, etc)

Question by /u/drcode

I won't talk about low-level opcodes here because of the brevity of the answer. In general, there are four ways functions can be called in Solidity:

	// WHATEVER YOU DO, DON'T USE THIS.
	// This is a bit of demo code posted to illustrate a principle. It is unaudited,
	// probably full of bugs, and definintely not production ready.
	// https://twitter.com/nicksdjohnson/status/1041642345467404291

	contract DumbWallet {
	mapping(address=>bool) public authorised;

	event Authorised(address indexed target, bool value);
	event Call(address indexed target, uint value);

	using System;
	using System.Collections.Generic;
	using static System.Console;

	namespace Union
	{
	class Program
	{
	public static void Main()
	{

	let cache = new Map();
	let pending = new Map();

	function fetchTextSync(url) {
	if (cache.has(url)) {
	return cache.get(url);
	}
	if (pending.has(url)) {
	throw pending.get(url);
	}