Friday, August 05, 2022

Zero Arguments Methods

In my book Advanced Java Game Programming, I have a sidebar recommending named notation as a work-around for the Java programming language not supporting named arguments.  Here is the example from the book as converted to the Rust programming language:

let game_data = SerializableGameData::new(
  10,  // health
  99,  // wealth
  18); // wisdom

There is a proposal to bring named arguments to Rust but until this proposal is adopted I have started using a new work-around which I am calling "zero arguments methods".  Here is a static function to be converted:

pub fn periodic_savings_needed(
  f: f64,
  r: f64,
  t: f64,
) -> f64 {
  f * r / ((1.0 + r).powf(t) - 1.0)
}

Here is the equivalent using a zero arguments method:

#[derive(Clone, Copy, Debug)]
pub struct PeriodicSavingsNeeded {
  pub future_value: f64,
  pub interest_rate: f64,
  pub time_periods: f64,
}

impl PeriodicSavingsNeeded {
  pub fn calculate(&self) -> f64 {
    let f = self.future_value;
    let r = self.interest_rate;
    let t = self.time_periods;
    f * r / ((1.0 + r).powf(t) - 1.0)
  }
}

Here is how the zero arguments method can be called:

let calculated_value = PeriodicSavingsNeeded {
  future_value:  1_000_000.0,

  interest_rate: 0.12,
  time_periods:  10.0,
}.calculate();

 

Saturday, July 30, 2022

First Published Crate

Today I published my first Rust crate to crates.io.  Crate com-croftsoft-core is an adaption to Rust of the Java-based CroftSoft Core Library.  After publishing this crate, I was able to use it as a dependency in my Yew-based retirement calculator.

The crate only has a single financial calculation function and a few constants right now.  I hope to eventually expand it to include most of the code from the CroftSoft Core Library.  Converting my old Java code library is another way for me to learn the Rust programming language.

Sunday, July 24, 2022

Rust, WebSockets, and Yew

Almost two decades ago when I wrote my book Advanced Java Game Programming, I ended it with three chapters on the subject of multiplayer network communications over Hypertext Transfer Protocol (HTTP).  The final chapter demonstrated a browser-based chat applet in which 2D characters would move about in response to player clicks on the screen.  I described how to use what I called "HTTP Pulling", now known as HTTP Long Polling, to receive messages from the server through the firewall.

The modern replacement for HTTP Long Polling is WebSockets which is now supported in all major browsersLast weekend I was able to write my first browser-based application in the Rust programming language by using the Rust-based front-end framework Yew.  Today I was pleased to be able to successfully implement a browser-based chat application using WebSockets and Yew by following the instructions in the online tutorial Let’s Build a WebSockets Project With Rust and Yew 0.19 by Johnny Tordgeman.

 


Sunday, July 17, 2022

The Rust Book

Tonight I finished reading The Rust Programming Language, informally known as "The Rust Book", by Steve Klabnik and Carol Nichols with contributions from the Rust Community.  The print copy published by No Starch Press covers the 2018 Edition of Rust.  There is also a free online version which is updated continuously.

I had started reading the Rust book last year and made it three-quarters of the way through.  This year I restarted from the beginning so I could refresh on the fundamentals.  It helped me understand a couple of Rust game programming books that I was reading simultaneously.

The book is well written with many code examples which are described in detail.  The authors ease the readers into the subject but then rapidly advance to more complicated topics in later chapters.  I assume that this is because they wanted to cover the entire programming language in just over five hundred pages.

I searched the Web to see if there is a second edition of the book coming out that covers the 2021 Edition of the Rust programming language.  Apparently there is not so I might start reading the online version for the updates and to review the material.  To help take me to the next level, I ordered from the same publisher Rust for Rustaceans: Idiomatic Programming for Experienced Developers by Jon Gjengset.

Saturday, July 16, 2022

Retirement Calculator

Back in 1999 when the stock market was doing well, I wrote a browser-based retirement calculator application using the Java Servlet framework.  Since a Java Servlet renders the Hypertext Markup Language (HTML) server-side, the application stopped working when I stopped using the Java application server.  Since the application does not fetch or store data using a back-end server, I could have re-written the calculator as a JavaScript-based application and simply hosted it on a website fronted by a Content Delivery Network (CDN).

Now in 2022 when the stock market is not doing so well, I converted the application to my new favorite programming language Rust using the front-end framework Yew.  Yew compiles the Rust code to WebAssembly (Wasm) which then runs in the browser just like JavaScript.  You can view the converted source code and play with an online demonstration hosted on one of my websites deployed using Amazon Web Services (AWS) Amplify Hosting.

 

Sunday, July 10, 2022

Rust and WebAssembly

My New Year's resolution this year was to learn the new Rust programming language.  I wrote a Hello, World! program in Rust many years ago and started reading the Rust book last year but now I am really getting into it.  You can follow my efforts on my new GitHub account.

My older open source Java code is hosted on SourceForge.net.  Many of my applications are Java game applets.  Now that Web browsers no longer support applets, I am exploring WebAssembly which can run both in browsers and in servers.

Today I was able to deploy a game that runs in the browser by following the instructions in the book Game Development with Rust & WebAssembly by Eric Smith.  I wrote the code in Rust, compiled it to WebAssembly, and then wrapped it in a thin layer of JavaScript so that it can run in a webpage.  You can play the game online at my GameSpawn website.

Sunday, June 26, 2022

Specialist Pools

If a software development team gets to be too large, you might be able to refactor a monolithic application into microservices.  You can then split the team into smaller teams, each dedicated to its own microservice.  Within the smaller team, you can have specialists, each focused on a different technology such as front-end, back-end, automated testing, or DevSecOps.

If you instead decide to keep the larger team dedicated to a single codebase, you might be able to split the team into Specialist Pools.  Each pool of specialists is focused on a single technology and each has its own Specialist Lead.  Since not all feature development stories require work in all technologies, members of the specialist pool can be assigned as needed where needed.

At regular increments of some number of months, one member of each pool can be rotated to another pool.  This permits the developer to get breadth across the technologies while at the same time conserving the depth of knowledge within the remaining members of the pool.  If more than one developer from a pool is volunteering to rotate, the one who has been in the pool the longest might be given preference.

Sunday, December 19, 2021

Babel Tower Programming

In the ancient story of the Tower of Babel, all of Humanity is unified in a common language.  They begin to construct a great tower which, in some variations of the story from other civilizations, might save them from possible extinction from another Divine Flood sent by an angry God.  Construction of the tower is abandoned when God disrupts the ability of Humanity to communicate by dividing their shared language into many.

Babel Tower Programming is what I call a form of Polyglot Programming in which the use of multiple computer programming languages impedes rather than promotes progress.  An example might be using one programming language for front-end development and a separate for the back-end when the same language could be used for both.  One sign that you are experiencing the impedance of Babel Tower Programming is when software developers are choosing their feature development tasks based primarily on which programming language will be used.

The solution, which I call the Incantation of Nudimmud, is to adopt a policy which requires that any new software features be developed in a common programming language.  Legacy code developed in the abandoned programming languages can be gradually phased out using techniques such as the Strangler Fig Pattern.  As Babel Tower Programming is a form of Technical Debt, the decision to move to a single language usually requires some cost analysis and both bottom-up and top-down support.

 

Saturday, September 25, 2021

Head First Agile

I just finished reading from cover to cover the book Head First Agile: A Brain-Friendly Guide to Agile Principles, Ideas, and Real-World Practices. Even before I finished reading it, I started recommending this book to my co-workers. I tell them that they can get almost everything they need to get started in Scrum by reading just the first four chapters.

I own a number of books in the Head First series. Like the For Dummies series, the "Head First" books provide fun introductions to a variety of topics. Unlike the "For Dummies" series, you do not have to explain that you are not trying to insult someone when you recommend one of their books.

rugby scrum