One thing that I learned is the benefits of pushing side-effects i. To recap, pure functions are those that the output is strictly a function of the inputs. One of the benefits of pure functions is that the function can be tested completely in isolation, as John Carmack noted above. When I started making a point of doing this, the benefits started becoming quite apparent. In fact, I started to get the suspicion that not practicing this was one of the main reasons the code I wrote would become increasingly untestable and difficult to change—which led to the feeling that my code was collapsing under its own weight.
In fact, I still have a very vivid memory of when this problem killed a project I was working on. You first wrote a lexical analyzer to tokenize the input using lex , then the compiler that would turn the tokens into an abstract syntax tree using yacc , turn it into some intermediate format, and then emit assembly code.
And then use as to compile. It started off great, especially since I had written lexers and parsers before. In other words, I had written the compiler phases in a way where each phase was no longer independently runnable, let alone testable. I was good enough where it was not really a problem until the very last phase, where we were executing our SPARC executable program. I remember my compiler working for all the test cases, until we had to implement recursion. Then it started blowing up after a certain number of recursive calls—after several all-nighters, I finally figured out that I was incorrectly computing the memory locations of variables on the stack, probably incrementing the stack pointer the wrong way.
After a certain number of recursive function calls, the generated program would just segfault and die. I probably got one of the lowest grades in the class. What I had learned was that burying my code so that it could only be executed inside other functions violated the principle of composition—the ability to run and test it, independent and isolated from the other modules. My thanks to Dr. Stephen Magill for taking the time to explain this to me, who also helped me write my first Haskell program! In Clojure, I fell in love with the convention of marking impure functions with a!
This includes any function that reads from disk or a database, let alone writes to one—after all, even external inputs make the output impure. These effectful functions should be pushed to the beginning or the end of your program, which makes everything in the middle independently runnable and testable. And of course, many people learned this twenty years ago, either by intuition, experience, or by reading great books such as Refactoring: Improving the Design of Existing Code by Martin Fowler. But knuckle-headed me only learned after being forced to confront this in Clojure, which seems to bring these problems to the front and center.
Something else happened during my first rewrite of TweetScriber that primed me for another Clojure aha moment. But reading through the exercises, it seemed to discuss something very, very important, with some profound lessons in how program state leads to incredible complexity—more things that have caused my programs to eventually collapse in on itself. In other words, in the jQuery implementation, the flow of information from one component to another becomes entangled. The diagram below shows it magnificently.
Wanderlust 108 Events
In contrast, consider the the same functionality implemented with something like React, in a more functional style, where state is mutated in one place, and all the UI elements are rendered from the state. State is changed in a very uniform way, and the UI is rendered as pure functions, never mutating state. I found this to be a shockingly convincing argument about how code should be written. In my ClojureScript rewrite using re-frame, it addressed one of the problems I found in using React, which was state is scattered across all the components.
This has been so successful for me that I will never write a client web app in any other type of framework. Rich Hickey is the inventor of Clojure, and his talks and Clojure have so much affected how I think about software—in fact, this entire blog post attempts to frame some of these aha moments. The talk is on the InfoQ site here which shows the slides associated with the soundtrack , and you can find a wonderful transcript of the talk here.
How to Write a Love Letter (with Sample Letters) - wikiHow
You can also find a version of the talk he did for the Ruby and Ruby on Rails community on YouTube here. Among many other things, he talks about how limited the human brain is in its ability to reason about things, to keep track of things, to grapple with complexity like the jQuery example above. He stated that the difference in cognitive capability between your average programmer and your average programmer is not the vaunted 10x difference.
He said emphasis mine :. Then we have this other part though, which is the mental capability part.
We have to make things near by simplifying them. The average juggler can do three balls. The most amazing juggler in the world can do, like, 9 balls or 12 or something like that. He talks about the need for simplicity in the software we write, and the stuff that we write our software in. The conditions for simplicity include having components that are completely decoupled from each other with no knowledge each other.
Hickey goes through the some of the core concepts in programming languages, and describes the extremes of which represent the ideal of simplicity and which ones represent complexity that eventually leads to the inability to understand and safely change our code, as well as misery and catastrophe.
As I mentioned in the beginning of this article, The Unicorn Project download the excerpts is about the invisible structures that enable developers to be productive. So much of this comes from the concepts that Rich Hickey has espoused over the years, and which have become infused into Clojure and the Clojure community:. It is a verb that means to turn something simple into something complex. Now take those same four strands of yarn and braid them together. In the simple system, you can change one string independently without having to touch the others. Which is very good. In fact, for many things you may want to do, you simply cannot, because everything is so knotted together!
You must schedule meetings with other teams, try to convince them to change something for you, escalate it to their managers, maybe all the way up the chain. I want to memorize your soul which will never fade and wither through our old age. I want to give you my heart, in trust that it will be your most important possession and you will do anything and everything to protect it. In exchange for mine, I will seize your heart and refuse to let go. I'll keep you captive, a prisoner of my love.
I want to wake up in the morning by your side with a smile on my face because you're the first thing my eyes are blessed to see. I want to sit on a park bench drinking coffee and read you my favorite books. I want to stay up until 2 AM looking at the stars, hearing your secrets and introducing you to my recently discovered music. I want to look at you and feel the compulsive urge to smile, knowing whatever is going on around the globe is alright since I have you. I want inside jokes and nonverbal conversations. Our relationship will be an adventure in itself, but with you my beloved, I want to discover the world.
- Giraffe! Fun Facts for Kids - A Giraffe Picture Book of the Reticulated Giraffe, West African Giraffe & Other Species with Amazing Facts.
- COME SONO GUARITO DAL CANCRO (Italian Edition).
- See a Problem?.
- Uomini, critiche e amori (Italian Edition).
I have an overabundance of love to give you, and I'm anxious for our future. Never will you doubt my love, or question my affections for you. Although I can be unsure of a lot of things in life, I never want to be unsure of you. I vow to support you in your wildest dreams and to help you create even more earth-shattering ones in the future. Photo by M Car. Jeanine Cerundolo is a holistic life coach with a degree in spiritual psychology from Columbia University. She loves supporting others to find inner peace and their own rich creative expression through self-exploration and personal growth work.
In her free time, she loves to write, especially poetry for the page or the stage!
- I get that people usually write letters to their younger selves, but I decided to write to you.!
- Love Letter To Clojure (Part 1).
- A Love Letter to You, My Future Sailboat;
- Die drei !!!, 12, Popstar in Not (drei Ausrufezeichen) (German Edition);
- Une liaison interdite (Harlequin Prélud) (Prelud) (French Edition).
This site is not intended to provide and does not constitute medical, legal, or other professional advice. The content on Tiny Buddha is designed to support, not replace, medical or psychiatric treatment.
I Dream of Sailing
Love Letter From the Future
It's about us. Your stories and your wisdom are just as meaningful as mine. Click here to read more. Think Web Strategy. Here are two key nuggets from the essence of the letter, which I found salient and beautiful: 1.
Coffee with Comrades
The desire for balance My fifteen-year-old self was so stressed! Self- Acceptance Contrary to my belief, my fifteen-year-old self did not have any demands of me, or false expectations or goals that I might have failed to meet. In what ways can you create a time capsule for yourself? As you write, consider these questions: What hopes do you hold for yourself in the future? What fears and obstacles do you currently face that you wish to overcome? What internal resources do you inherently possess that will help you, now and always? What goals do you have that you aspire to?
Related A Love Letter to the Future
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