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/* |
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Date: 17.V.2011 |
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Author: pumbur <pumbur@pumbur.net> |
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*/ |
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#+SETUPFILE: ../config.org |
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#+OPTIONS: toc:nil |
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#+EXPORT_FILE_NAME: coh.html |
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#+DATE: 2021-02-11 |
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#+TITLE: Code of Honor |
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#+PAGE: true |
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|
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I always try to live by my code of honor. A man is nothing without his honor. “A sin is to betray your beliefs”. |
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|
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* Honorable life |
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- Don’t betray your code of honor. |
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- Defend your Bushido way. |
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- Live life as a Honorable Man. |
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- Don’t lie. |
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- Honesty takes courage. |
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- Don’t talk without a knowledge to support it. |
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- “Don’t argue with the crazy guy”. |
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- Always follow your sense of Justice |
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- Feel the pain of others. |
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- Always put your self in people’s shoe before making any decision. |
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- A simple smile goes a long way. |
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- There’s no honor in winning by cheating. |
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- “If you fall down 7 times make sure to get up 8 times.” |
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- Protect your promises. |
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- “For a samurai everywhere is Japan.” |
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- Holding back is disrespectful to your opponent. |
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- Live life in your way. |
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- “Respect is earned, not given”, So earn it. |
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- “A man is much more than the job he holds and clothes he wears.” |
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|
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* Science |
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|
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#+BEGIN_QUOTE |
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Truth is sought for its own sake … Finding the truth is difficult, and the road to it is rough. |
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For the truths are plunged in obscurity … God, however, has not preserved the scientist from error |
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and has not safeguarded science from shortcomings and faults. If this had been the case, |
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scientists would not have disagreed upon any point of science… Therefore, the seeker after the |
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truth is not one who studies the writings of the ancients and, following his natural disposition, |
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puts his trust in them, but rather the one who suspects his faith in them and questions what he |
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gathers from them, the one who submits to argument and demonstration, and not to the sayings |
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of a human being whose nature is fraught with all kinds of imperfection and deficiency. |
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Thus the duty of the man who investigates the writings of scientists, if learning the truth is his |
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goal, is to make himself an enemy of all that he reads, and, applying his mind to the core and margins |
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of its content, attack it from every side. He should also suspect himself as he performs his critical |
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examination of it, so that he may avoid falling into either prejudice or leniency. |
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|
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–- [[https://en.wikipedia.org/wiki/Ibn_al-Haytham][Ibn al-Haytham]] |
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#+END_QUOTE |
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|
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* Software Engineering |
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|
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- Simplicity over Complexity |
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- Simple first, then Easy |
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- Abstraction, Abstraction, Abstraction |
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- Put your conventions layer on top of a well written abstraction |
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- Always choose a name for your variables which implies the variable content or usage. |
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- Never ever use variable names such as x, a, b, etc. |
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- Bugs before new features |
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- Docs before new features |
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|
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** Library design |
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Major releases can contain backward incompatible changes. It’s better to use a different code name |
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instead of a major version number change to indicate that there going to be backward incompatible changes. |
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Minor releases shouldn’t break the dependency versions. E.g: X(0.6.0) depends on Python(3.5.x), X(0.7.0) |
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should depends on the same version python |
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|
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** New Feature Checklist |
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- Is it easy to extend the feature ? |
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- Is it scalable ? |
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- Is it easy to maintain ? |
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- Is it well documented ? |
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- Does it have the best possible performance ? |
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- What about tests ? |
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- Is it following the correct coding style ? |
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|
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** Resiliency Checklist |
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|
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- Things that might fail: |
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+ Dependent systems |
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+ Network |
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+ External storage |
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+ Database |
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+ “The Cloud” |
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@ -0,0 +1,180 @@ |
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#+SETUPFILE: ../../config.org |
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#+TAGS: Serene(s) Languages(l) |
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#+CATEGORY: Engineering |
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#+DATE: 2019-12-07 |
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#+TITLE: Choosing the target platform |
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|
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After wrapping my head around the [[file:rational-and-a-name.org][rational]] of [[file:my-new-programming-language.org][My new programming language]], I have |
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a big decision to make. Choose a platform. |
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|
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As programmers, we have a tough life when it comes to making a decision that |
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has direct impact on our product. I'm pretty sure you went through this process |
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at least once. From choosing a semantically great name for a variable to choosing |
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a right technology for your next billion dollar startup. It is always hard to |
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pick a tech stack for a new project. Especially when the new product happens to be |
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a new programming language. If I get my hands dirty with a wrong tech stack for |
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a simple web application, no big deal. I still can rewrite the whole thing and |
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pay a penalty. But in the case of programming languages that's not the case. Wrong |
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platform can easily destroy you. From the dawn of computers, many smart people |
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created tons of languages. But only few of them made it to the top. While there |
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are so many reasons for their success, going with the right platform is one |
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the most important ones. |
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|
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The obvious question that comes to mind when we're talking about "The platform" |
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is, should we build a platform from scratch or should we piggyback on others? |
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Creating a programming language and a virtual machine from scratch is gigantic and |
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bone crushing task. It needs a crazy set of skills and knowledge. Even with such |
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wisdom and experience people who went through it has made many mistakes and had to |
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constantly iterate to come up with the right implementation. The evolution of |
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programming languages such as [[https://en.wikipedia.org/wiki/Scheme_%28programming_language%29][Scheme]] is a good example of it (for more information |
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take a look at [[http://www.r6rs.org/][R6R5]]. |
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|
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Building a VM is hard and Building a fast VM is even harder. While I think creating |
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a programming language and a VM from scratch is really fun, but it can be really |
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frustrating as well. I don't want to get annoyed with myself during the process and |
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abandon my goal. I should ride on the shoulders of the giants to gain benefit from |
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their great work. I should choose a platform that helps me to move faster and iterate |
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through different ideas quicker. |
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|
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From a technical perspective, Starting from scratch means that I have to write a |
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program that includes at least a parser and a compiler. Building a compiler |
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is no joke. Hypothetically let's say we have a working compiler and parser, What |
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about use libraries and ecosystem ?? It would be really hard to convince people |
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to use a programming language that does not have any useful library and they have |
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to build everything by themselves. It might have been the case 30 years ago but |
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it is not the case in the modern age of programming languages anymore. |
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|
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So the idea of creating [[https://serene-lang.org][Serene]] from scratch is out of the picture. We need to find a good |
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platform for it. But what are the options ??? |
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|
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* Racket :Serene:Languages: |
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#+BEGIN_QUOTE |
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Racket is a general-purpose programming language as well as the world’s first ecosystem |
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for language-oriented programming. Make your dream language, or use one of the dozens |
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already available. |
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#+END_QUOTE |
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|
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[[http://racket-lang.org][Racket]]is a dialect of Lisp which allows us to build our own language by extending it. While |
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Racket is really cool and have a long list of pros and [[https://beautifulracket.com/appendix/why-racket-why-lisp.html][many reasons why to use it]] |
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(It's Lisp after all), it has the disadvantage that forced me to stop thinking about it |
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for *Serene*. As I mentioned in the [[file:rational-and-a-name.org][rational]] I'm not trying to build a toy language or |
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a domain specific one and Racket's ecosystem isn't as great as a battle tested and well-known |
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ecosystem like Java or Python (or other popular ecosystems). |
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|
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* Javascript |
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We're living in the age of Web and one of the big players in this era is Javascript. The number |
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of the programming languages that compile to Javascript is increasing rapidly. Javascript |
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as a language [[https://whydoesitsuck.com/why-does-javascript-suck/][sucks]] but as platform it is amazing. Lots of money and engineering effort has |
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been spent on improving Javascript engines. As a result Javascript is a crappy language with |
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well engineered engines such as [[https://v8.dev/][V8]]. |
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|
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Creating a language based on Javascript platform means that I have to be involved with the whole |
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transpiling scenario and deal with the fact that this new language can be used on different |
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browsers or on the backend. Or even on IE6 (Just kidding). I don't want to deal with all this. |
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I think Javascript platform can't be a good fit for what I need. So I won't go into details about |
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it |
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|
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* Python |
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Python is another famous platform form creating programming languages. Many people have built |
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programming languages on top of Python (Checkout [[http://norvig.com/lispy.html][Lispy]] if you're a Python fan). Python is super |
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popular these days and you'll see it everywhere. Creating a language on top of Python (just |
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like Javascript) gives me access to a rich ecosystem with huge number of libraries and a robust |
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ecosystem. |
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|
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But as I mentioned in the [[file:rational-and-a-name.org][rational]] I want support for built-in concurrency and parallelism. |
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Python isn't even good when it comes to parallelism and concurrency. I'm using python for more |
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than 10 years now and I'm very familiar with it. I know about all the effort to create useful |
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concurrency and parallelism such as asyncIO. But the fact is Python is not designed for this job. |
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*The GIL* is a huge problem in Python that literally prevents us from Running two pieces of code |
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in parallel in two kernel space thread. It is a problem for me. If you can't do a decent concurrency |
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and parallel execution you have no chance against modern languages like Clojure, Go, Elixir and others. |
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Python is fine now despite of its problems because it is good at other stuff and people accepted it |
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for what it is. Python is out there for about 25 years now and it has established a big community. If |
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Guido van Rossum created Python a year ago, I'm pretty sure that it would've failed because |
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it can't compete with modern languages. Don't get me wrong, I'm not trying to trash Python. |
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It is great and it has many good qualities but a good Concurrency and parallel execution model |
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ain't one of them. |
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|
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* BEAM |
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Erlang ecosystem is amazing, Robust and well tested. I have read a lot about it and when |
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ever I'm studying anything around computer science that can be related to Erlang, I ask |
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myself "How is Erlang doing it?". Erlang ecosystem truly had a huge impact on the world |
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today. |
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|
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The problem with Erlang ecosystem for me is that I always read about it and my knowledge |
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around it is only theoretical. Building a language on top a platform needs a good level |
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of practical experience on the platform as well which I don't have that. So it's obvious |
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that I have to pass. |
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|
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* The JVM |
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As much as I dislike Java (Mostly because of the syntax and the fact that it is an object |
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oriented language), I like JVM a lot. The JVM is battle tested, well design (Well, sort of. |
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But it's certainly evolving.) and fast VM. It should be the most popular VM in the world |
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(I'm just guessing). It is one of the world's most heavily-optimized pieces of software. |
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Plenty of researches have been made to make it better and better. |
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|
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The JVM has a mature ecosystem and a massive community of developers that resulted in an |
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unbelievable number of libraries (not the largest though, NPM is the largest artifact |
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repository. But it has a huge amount of useless BS as well). By targeting the JVM, |
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users will have an easy time adopting the new languages because of the rich tools set |
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provided by the Java ecosystem and all the languages that targeted JVM as well. For example, |
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it will be possible to use libraries written in Scala or Clojure as well. |
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|
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Long story short, I think the JVM is the right platform for me. The fact that many languages |
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have chosen it as their base platform shows how useful it can be. But there is a problem. |
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Targeting a higher level virtual machines like the JVM means that I'll have an easier job to |
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create a compiler. But I still have to write one. A compiler that takes the code and produces |
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JVM bytecode. As I mentioned earlier, writing a compiler is an enormous task and the chance |
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of doing it wrong with someone like me who has never built a compiler before is very high. |
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|
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* One VM to rule them all |
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Luckily there is a solution. I can write an interpreter in a VM that is designed to optimize |
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my interpreter with all that wonderful JIT compilation magic. Oracle has released a new VM |
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that hopes to make writing language interpreters both easy and fast. It can also leverage |
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the huge ecosystem of the JVM. It is an enhanced JVM that contains a new JIT compiler which |
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can speed up interpreters to near Java speed. The new JIT compiler is called Graal. To use |
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the Graal’s JIT magic we can use the Truffle library to create the interpreter. We will |
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annotate the interpreter and give Graal some hints on invariants and type information. |
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According to Graal's documents, By doing this integration effort we get significant speedups |
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in out interpreter without having to resort to writing a bytecode compiler. |
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|
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[[https://www.graalvm.org/][GraalVM]] is a Java VM and JDK based on HotSpot/OpenJDK, |
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implemented in Java. It supports different execution modes, like ahead-of-time compilation |
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of Java applications for fast startup and low memory footprint. |
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|
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#+BEGIN_QUOTE |
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GraalVM is a universal virtual machine for running applications written in JavaScript, |
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Python, Ruby, R, JVM-based languages like Java, Scala, Groovy, Kotlin, Clojure, and |
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LLVM-based languages such as C and C++. |
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|
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GraalVM removes the isolation between programming languages and enables |
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interoperability in a shared runtime. It can run either standalone or in |
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the context of OpenJDK, Node.js or Oracle Database. |
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#+END_QUOTE |
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|
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I copied the above paragraph from GraalVM's official website. It is truly a VM to rule |
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them all. |
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|
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[[https://github.com/oracle/graal/tree/master/truffle][Truffle]] library is one the key players in GraalVM. The initial results of Truffle are |
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super exciting. Implementations of Ruby in Truffle has a performance on the same order |
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of magnitude as the much bigger projects of JRuby. Just checkout [[https://chrisseaton.com/truffleruby/][Truffle Ruby]]'s |
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website to get amazed by it. There is a [[https://github.com/graalvm/graaljs][javascript implementation]] as well which showed |
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great progress as well. Lots of research has been dedicated to this topic and the result |
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is mind blowing. The interesting thing is that these Truffle implementations were done with |
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fewer people in a shorter period of time. This means you can create your own language on the JVM that |
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takes advantage of all it’s existing libraries, native threading, JIT compiler without |
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having to write your own compiler, and you get speeds that took other languages years |
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to achieve. |
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|
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Using GraalVM as the platform for my new language will help me to be much faster because |
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All I need to do is to build an [[https://en.wikipedia.org/wiki/Abstract_syntax_tree][AST]] interpreter and Graal will handle the rest. It means |
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that I can start by building what is important and use a very well engineered toolkit in |
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my advantage to get to my goal quicker and then later on replace any part that I like with |
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my own implementation. How cool is that??? |
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|
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But as an engineer and a wannabe scientist I'd like to see the proof with my own eyes. Not |
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because I don't trust academic work, Just because it feels good to experience the proof. |
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|
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So to begin with I'm going to create a dead simple Serene interpreter in Java and OpenJDK |
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and then build the same interpreter using Java on GraalVM using Truffle library and |
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compare the results and prove myself that choosing GraalVM is the right choice. |
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@ -0,0 +1,49 @@ |
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#+SETUPFILE: ../../config.org |
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#+TAGS: Serene Languages |
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#+CATEGORY: Engineering |
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#+DATE: 2019-11-25 |
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#+TITLE: My new programming language |
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|
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As a software engineer, one of my joys in life is to learn new things. I can't describe the |
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pleasure of learning a new technology or stepping forward in the world of science. If you experienced |
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such a delight, you would know that how addictive it is. I can't satisfy my hunger for knowledge and |
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it might sounds like a gloat but it's truly joyful (ok mate, you love to "read", get on with it). |
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|
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Programming languages are the most common tool among programmers and software engineers (Duh!). |
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I believe that learning new programming languages helps us to widen our vision as engineers and |
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help us improve our mentality about software architecture and design. So clearly I never say "No" |
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to learning a new programming language and because of that I have lots of experience with different |
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languages. Each language taught me tons of new things and helped me enhance my skills. I've studied |
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many languages and have a long list of them as my "To Learn" list. |
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|
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Approximately a year ago, I was frustrated with Python and nagging to my wife about it (She always listens to |
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my gibberish). All of a sudden she suggested to me that "Why don't you write your own programming language ?". |
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That got me thinking, "Is it a good idea to do so ????". |
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|
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* My way of learning :Languages:Serene: |
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People have different routines for learning. I'm one of those people who likes to learn new |
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things by understanding how it works first. I'd like to start my learning process by understanding |
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the laws of the universe. In this case, "universe" is the implementation and theory behind |
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the thing I'm trying to learn. It might seem like crazy idea but that's how I learn better. |
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For instance, when I was a teenager and was learning about how to use Gnu/Linux, I was so |
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obsessed with internal of a Linux distribution to a degree that I decided to build my own |
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distribution. Of course as a teenager I was naive and dreamed about my distro ( Which I used |
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to call Liniera ) to become a well-known and popular distribution. Aside from my childhood dreams |
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I learned a lot by creating a distribution. Learned about Linux kernel, boot process, bootloaders |
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and tons of other complicated pieces that normally people don't get to know at first (I was using |
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LFS and Debian tools). So after that delightful but tough experience, I always try to build a minimal |
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prototype of whatever I'm trying to learn to comprehend the universe of that thing which |
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helped me a lot to this day. |
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|
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Based on my history, routines and the question that my wife has planted in my mind and after about a year |
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researching and thinking about it, Finally I realized it can be a good idea to create a new |
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programming language. To be honest it is not a task to be taken lightly. Whenever I created something |
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that wasn't out of my needs, I just failed. But this time I think creating a programming language can |
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massively help me to gain a better grasp of "the universe". Trying to overcome this challenge will help |
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me to grow and be a better engineer despite the fact that this new language may not even make it to the |
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list of known programming languages. I'm fine with that as long as it pushes me a step forward in my way |
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of life and brings me joy of wondering around in the world of science and engineering. |
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|
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I'm going to write more blog posts about my journey through this humongous task as a journal for myself and other |
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enthusiastic people. After all it will be a hobby of mine and not my day to day job. So I'll take my time and |
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move slowly but steady. |
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@ -0,0 +1,52 @@ |
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#+SETUPFILE: ../../config.org |
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#+TAGS: Serene Languages |
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#+CATEGORY: Engineering |
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#+DATE: 2019-12-01 |
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#+TITLE: Rational and a name |
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|
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*This post is a draft and I'll finish it gradually* |
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|
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As I mentioned in [[./my-new-programming-language.org][My new programming language]], I'm creating a new programming language. |
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I'll try to pick up good points of different programming languages and avoid the cons |
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of them. One of the most important aspects of any project is to have a rational for it. |
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It's what I learned from [[http://clojure.org][Clojure]]'s culture. Rationals are a big deal in any clojure |
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developers world. As fan I'd like to start my new programming language by writing down |
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the rational of what I'm trying to achieve. |
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|
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* Rational (Take 1) and goals :Languages:Serene: |
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So far, the main reason to create a new language for me is to *learn more and |
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educate myself*. But it doesn't mean that I'm aiming for a toy language. I want |
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to create a general purpose language that solves some problems. Here is a list of |
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reasons that made me consider the idea of creating a new language (in no specific order): |
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|
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** Lisp is superior |
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I think the world needs more and more dialects of Lisp. It's the second oldest |
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programming language in the world and as far as I know the oldest one that is |
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still active. **Lisp** is elegant and amazing, but unfortunately not so many |
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programmers know about it. Even most of the those people who heard the name |
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are distracted by the "parenthesis". But they're missing the fact that there |
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is a good reason for all those parenthesis. Lisp is the simplest language I |
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know, its programs are written in its own datatypes. How simple is that??? |
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|
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You might hear that [[https://twobithistory.org/2018/10/14/lisp.html][God has created the universe in Lisp]]. |
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Lisp is amazing and I consider a programmer who has understood *the Lisp way*, the |
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[[https://twitter.com/lxsameer/status/1172220581992980480][luckiest]]. |
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|
|||
I'd my new language to be Lisp, because just being a Lisp brings a huge deal to the |
|||
table. |
|||
|
|||
** Simplicity |
|||
** FP is the future |
|||
** Development process |
|||
** Better core development |
|||
** Built-in Concurrency and parallelism |
|||
|
|||
* A Name |
|||
If you're a programmer, I'm pretty sure that you already experienced the terror |
|||
of trying to find a name for your project. Frankly, It's even hard to find a good |
|||
name for your variable. |
|||
|
|||
After about 10 days of searching finally my wife came up with a good name. *Serene*. |
|||
Calm and peaceful. I like it. It's simple and beautiful with a great meaning. |
|||
|
|||
I can't wait to start working on it. :P |
|||
@ -0,0 +1,257 @@ |
|||
#+SETUPFILE: ../../config.org |
|||
#+TAGS: Serene(s) Languages(l) |
|||
#+CATEGORY: Engineering |
|||
#+DATE: 2020-01-03 |
|||
#+TITLE: Serene (simple versoin) |
|||
|
|||
As you might already know I'm working on [[file:my-new-programming-language.org][my own programming language]] |
|||
for a while now. I'm still on early stages and working on [[file:choosing-the-target-platform.org][choosing the right platform]] |
|||
for [[https://serene-lang.org][Serene]] and trying to spend time on doing enough research and make decision based |
|||
on facts, scientific papers and collected data from experiments |
|||
rather than rushing into things and end up with a mess. |
|||
I believe those languages that take their time and move slowly |
|||
but with great research, plan and design are more successful in |
|||
the long term (Thanks to *Pouya* for pointing it out). Take *Clojure* |
|||
as an example. They are taking their time, experimenting and validating |
|||
their hypothesis. As a result, Clojure is a well designed, stable |
|||
and highly backward compatible language with amazing and productive |
|||
pace. However, some other languages like Python are extremely |
|||
popular and consequently has more contributors. Dealing with all |
|||
those contributors caused Python to move faster than it should and |
|||
they ended up with some bad choices and horrible designs that |
|||
fixing them requires an humongous effort. Gradually, it becomes |
|||
harder and harder to fix those and move away from them. GIL is a good example, |
|||
instead of fixing the issue and removing the GIL, they are introducing |
|||
(at the of writing this article they added some basic support to latest |
|||
python release but far from what they want) [[https://lwn.net/Articles/754162/][something else]] to fix the original |
|||
problem but it might become a pain point itself. In order to avoid these kind |
|||
of problem as much as possible I'm trying to take my time and do as |
|||
many as experiments as I need. |
|||
|
|||
As I mentioned [[file:choosing-the-target-platform.org][earlier]] I think *GraalVM* and *Truffle* is the right answer for |
|||
Serene. But to verify my initial Idea I decided to run an experiment. |
|||
The experiment is all about implementing a Lisp in two environments. |
|||
A pure Java implementation vs a *Truffle* implementation. |
|||
|
|||
I spent several days and implementing the pure java version. The repository |
|||
of the simple version is available in the [[https://devheroes.codes/Serene/serene-simple][repo]] |
|||
This is a dummy version, but good enough lisp that I didn't paid too much attention |
|||
to the details and just created a very simple lisp with the following specification. |
|||
|
|||
#+BEGIN_QUOTE |
|||
Note: In this post whereever I use the name **Serene** for the implementation, |
|||
I'm referring to the simple version. |
|||
#+END_QUOTE |
|||
|
|||
* Data structures :Serene:Languages: |
|||
Since I tried to avoid unnecessary work, I didn't do much and implemented |
|||
just one collection type which is the most important and essential data |
|||
structure in any Lisp, the mighty List. While my final goal is to have functional |
|||
data structures, this List is not a functional one and is a simple linked |
|||
list. You can find the implementation under =serene.simple.ListNode=. |
|||
|
|||
For the number types I just added support for =Long= and =Double= |
|||
via `serene.simple.SNumber` class which acts as a dispatcher between two inner |
|||
classes. |
|||
|
|||
For Strings, boolean types and =nil=, I just used the equivalent Java data |
|||
structures directly. |
|||
|
|||
* Reader/Parser |
|||
Instead of using a parser generator or a sophisticated parser, I just created |
|||
a simple read ahead of position based parser that reads two chars and calls the |
|||
appropriate method to create the corresponding =Node=. the =serene.simple.Node= |
|||
is an abstract class that has just one important method, =eval=. The whole |
|||
purpose of the reader is to parse the code and create an AST like data structure |
|||
which each node extends the =Node= class (I should've create the interface for |
|||
it but too lazy to change it now). The =eval= method of `ListNode` is a bit |
|||
special. It calls the =eval= method on all the elements on the list |
|||
and then calls the first element as a function and pass the rest of the elements |
|||
as the arguments to that function. First rule of lisp :)) |
|||
|
|||
The =eval= method of =ListNode= contains lots more details regarding to java |
|||
interop as well which I leave it out of this blog post. |
|||
|
|||
* Scope |
|||
Scopes are simply a mapping between symbol names and values. Serene consists of two |
|||
different scopes, both implemented in =serene.simple.IScope= and extend |
|||
=serene.simple.AScope= abstract class that contains the logic for symbol |
|||
lookup and insertion. These two classes are =serene.simple.Scope= which |
|||
is the general scope and it has a parent/child type of relationship with |
|||
other instances of the same class or =serene.simple.RootScope= that is |
|||
the top level scope. Beside that, =RootScope= is pre-populated with all |
|||
the built-in functions and types. |
|||
|
|||
* Special forms |
|||
Serene's [[https://courses.cs.northwestern.edu/325/readings/special-forms.php][special forms]] are pretty limited. All of them all classes which extend |
|||
=serene.simple.SpecialForm= abstract class and inherit from =Node= indirectly. The |
|||
difference between special form evaluation and function evaluation is that in case |
|||
of special forms, Serene does not evaluate the arguments and leaves the evaluation |
|||
to the special form itself. Here is the list of Serene's special forms: |
|||
|
|||
=def=: Creates a binding between a symbol name and the given value: |
|||
|
|||
#+BEGIN_SRC lisp |
|||
(def name "serene") |
|||
#+END_SRC |
|||
|
|||
=fn=: Creates an anonymous function: |
|||
#+BEGIN_SRC lisp |
|||
(def inc (fn (x) (+ 1 x))) |
|||
#+END_SRC |
|||
|
|||
=quote=: Prevents the evaluation of the given argument and return it as it is: |
|||
|
|||
#+BEGIN_SRC lisp |
|||
(quote (1 2 3 4)) ;; => (1 2 3 4) |
|||
#+END_SRC |
|||
|
|||
=if=: Evaluates the body based on the return value of the given predicate. |
|||
|
|||
#+BEGIN_SRC lisp |
|||
(if (= x 1) |
|||
(...) ;; if x is 1 |
|||
(...)) ;; if x is not 1 |
|||
#+END_SRC |
|||
|
|||
=let=: Sets a local scope and runs its body using that scope. |
|||
|
|||
#+BEGIN_SRC lisp |
|||
(let ((x 1) |
|||
(y 2)) |
|||
(println x y)) |
|||
#+END_SRC |
|||
|
|||
=do=: Simply groups several expressions together. |
|||
|
|||
#+BEGIN_SRC lisp |
|||
(do |
|||
(println ...) |
|||
(if ....)) |
|||
#+END_SRC |
|||
|
|||
=cond=: Gets several predicates and only evaluates the body corresponding |
|||
to the first truthy predicate. |
|||
|
|||
#+BEGIN_SRC lisp |
|||
(cond |
|||
((= x 1) (body1...) |
|||
((= x 2) (body2...)) |
|||
(true (else...)))) |
|||
#+END_SRC |
|||
|
|||
* Builtin Function |
|||
All the build in function are created by extending the =serene.simple.builtin.AFn= |
|||
abstract class and follow the same =Node= convention. Here is a list of the most |
|||
important built in functions: |
|||
|
|||
=(println ....)=: Prints all the arguments on the stdout. |
|||
|
|||
=(quit)=: Quits the program. |
|||
|
|||
=(conj coll x...)=: Returns a new list by adding the given arguments. |
|||
|
|||
=(count coll)=: Returns the number of elements in the given COLL. |
|||
|
|||
=(reverse coll)=: Returns a new list which is the reverse of COLL. |
|||
|
|||
=(list 1 2 3..)=: Creates a list from the given arguments. |
|||
|
|||
=(first coll)=: Returns the first element of the given COLL. |
|||
|
|||
=(rest coll)=: Returns all the elements beside the first element of the given COLL. |
|||
|
|||
=(doc fn)=: Returns the documentation for the given symbol if any. |
|||
|
|||
=(reduce f coll initial)=: Reduces the COLL by applying F to its elements with the |
|||
INITIAL as the default value. F takes two arguments 1) the accumulation 2) the element. |
|||
|
|||
=(new Class arg1 arg2...)=: Create a new instance of the given CLASS by passing the given |
|||
arguments to its constructor. |
|||
|
|||
** Example program |
|||
Here is an example program in Serene simple version (=benchmarks/fib.srns= in the repo): |
|||
|
|||
#+BEGIN_SRC scheme |
|||
;; We have a reduce function but just in case... |
|||
(def reduce1 |
|||
(fn (f xs initial-value) |
|||
(cond |
|||
((first xs) (reduce f (rest xs) (f initial-value (first xs)))) |
|||
(true initial-value)))) |
|||
|
|||
;; A simple map function implementation in serene |
|||
(def map |
|||
(fn (f xs) |
|||
(reduce (fn (acc x) (cons acc (f x))) xs (list)))) |
|||
|
|||
(def range-list |
|||
(fn (x y init) |
|||
(if (< y x) |
|||
(do |
|||
(conj (range-list x (+ y 1) init) y)) |
|||
init))) |
|||
|
|||
(def range |
|||
(fn (x) |
|||
(range-list x 0 (list)))) |
|||
|
|||
(def fib |
|||
(fn (n) |
|||
(def fib-iter |
|||
(fn (x y z) |
|||
(if (= x 0) |
|||
z |
|||
(fib-iter (- x 1) |
|||
z |
|||
(+ y z))))) |
|||
(fib-iter n 0 1))) |
|||
|
|||
(def benchmark-fn |
|||
(fn (x) |
|||
(let ((start (now))) |
|||
(println (fib x)) |
|||
(- (now) start)))) |
|||
|
|||
|
|||
(def run-benchmark |
|||
(fn (times) |
|||
(map (fn (x) |
|||
(println "Benchmark: " x) |
|||
(println "Took: " (benchmark-fn 500))) |
|||
(range times)))) |
|||
|
|||
(run-benchmark 20) |
|||
#+END_SRC |
|||
|
|||
|
|||
* What is missing ? |
|||
Since Serene (simple) is an experimental language and I'll abandon it eventually. |
|||
I didn't want to fall into the rabbit hole and just tried to get to the point as soon as possible. |
|||
So I sacrificed lots of details. Here is a list of the most important missing |
|||
details: |
|||
|
|||
- A namespace functionality. Because creating and compiling dynamic classes |
|||
is a massive task and needs tons of work which doesn't make sense for a toy |
|||
project. |
|||
- Unified function interface. |
|||
- Requiring different namespaces. |
|||
- A sophisticated parser. My Reader implementation is really cheap that |
|||
suits a toy project. It might worth investigating on different solutions |
|||
including using a parser generator or ahead of time read implementation. |
|||
- Primitive functions in Serene. I used lots of primitive functions |
|||
from java rather than implementing them inSerene itself, mostly because |
|||
of two reasons. Lack of |
|||
macros and namespaces. |
|||
- Decent [functional] data structures. The only data structure I implemented |
|||
is list. |
|||
- Quality code. The general quality of this implementation is not great, I |
|||
sacrificed quality for time. |
|||
|
|||
* Conclusion |
|||
I'm not going to improve the simple version anymore at this stage. I'm going to run |
|||
some benchmarks and measure different aspects of the current implementation and then |
|||
I'll move to the *Truffle* version and continue experimenting. |
|||
|
|||
Please let me know if you have any comments or questions on this topic. As always |
|||
I'm available throw social media and email. |
|||
@ -0,0 +1,116 @@ |
|||
#+SETUPFILE: ../../config.org |
|||
#+TAGS: Databases |
|||
#+OPTIONS: toc:2 |
|||
#+CATEGORY: Engineering |
|||
#+DATE: 2019-04-26 |
|||
#+TITLE: Transaction Variants |
|||
|
|||
In this post I want to talk about different variants of [[https://en.wikipedia.org/wiki/Database_transaction][database transactions]], I assume you already |
|||
know about database transactions. So, let's cut to the chase. |
|||
|
|||
* Flat Transaction :Databases: |
|||
Flat transaction are those regular transactions we know about and are the most common transactions |
|||
in the [[https://en.wikipedia.org/wiki/Database#Database_management_system][DBMS]]s Flat transactions are simple but they can not address two problems: |
|||
|
|||
- Multi stage transactions |
|||
For example, Let's say we want to book flight from City C1 to C2. Since there is no direct fly we |
|||
have to book 4 flights from, =C1 -> CA -> CB -> C2=. The process of booking each of these flights |
|||
is a transaction by itself and the whole process is a transaction too. |
|||
|
|||
- Bulk updates |
|||
Let's say we want to update billion tuples. What if the very last tuple fails to update and cause |
|||
the transaction to abort. Then we need to revert the changes made by the transaction and revert |
|||
a billion tuples which obviously is a huge task. |
|||
|
|||
* Transaction Savepoints |
|||
These transactions are similar to flat transaction with addition of one extra thing which is |
|||
save points. So any where in there transaction users case ask for a save point and again they can |
|||
rollback to a save point or rollback the entire transaction. |
|||
|
|||
#+BEGIN_SRC sql |
|||
BEGIN |
|||
READ(A) |
|||
WRITE(A) |
|||
SAVEPOINT 1 |
|||
WRITE(B) |
|||
SAVEPOINT 2 |
|||
ROLLBACK TO 1 |
|||
COMMIT |
|||
#+END_SRC |
|||
|
|||
#+BEGIN_QUOTE |
|||
Note: *These transactions only solve the multi stage transaction problem.* |
|||
#+END_QUOTE |
|||
|
|||
* Nested transactions |
|||
Nested transactions are similar to save points transactions, but instead save points these |
|||
transactions break down to smaller flat transactions. Each transaction commits separately from |
|||
other transactions. But result of the parent transaction rule them all, so if the parent |
|||
transaction fails all the nested transactions have to rollback. |
|||
|
|||
#+BEGIN_SRC sql |
|||
BEGIN |
|||
BEGIN T1 |
|||
... |
|||
COMMIT T1 |
|||
BEGIN T2 |
|||
... |
|||
COMMIT T2 |
|||
COMMIT |
|||
#+END_SRC |
|||
|
|||
#+BEGIN_QUOTE |
|||
Note: *These transactions only solve the multi stage transaction problem.* |
|||
#+END_QUOTE |
|||
|
|||
* Chained transactions |
|||
In these kind of transactions, smaller flat transaction can be applied in a chain in the way that |
|||
the result of each of them is not visible to the outside world until the end of the chain. |
|||
|
|||
In theory chained transactions should be applied in sequence but in practice in some cases we can |
|||
interleave their operations. Also Between T1 and T2 of a chained transaction, No other thread of |
|||
code shouldn't be able to make changes to those resources which T2 will operates on. |
|||
|
|||
If any transaction in the chain fails, it has nothing to do with the previous transactions in the |
|||
chain. For example: |
|||
|
|||
#+BEGIN_SRC |
|||
T1 -> T2 -> T3 |
|||
S -> S -> F |
|||
#+END_SRC |
|||
|
|||
In the chained transaction above only T3 failed and T1 and T2 are successfully committed to storage. |
|||
We don't have to roll them back. |
|||
|
|||
While chained transactions can break big transactions into smaller pieces for better parallelism but |
|||
*they only solve the multi stage transaction problem* Not the bulk update problem. |
|||
|
|||
* Compensating transactions |
|||
This type of transactions are special transactions which are designed to semantically reverse the |
|||
effect of another transaction which already committed. |
|||
|
|||
One important thing to remember about compensating transactions is that they know how to revert |
|||
the /logical/ effect of other transactions /NOT the physical/ effect. For example, If a transaction |
|||
increase a counter by one. The physical revert would be to changes the binary data that inserted |
|||
for that counter to what it was before the transaction, but the logical revert would be to |
|||
decrease the counter by one when needed. |
|||
|
|||
So basically these kind of transactions know about how to put the database in correct state before |
|||
the other transaction. |
|||
|
|||
* Saga Transactions |
|||
A saga transaction is a sequence of chained transactions =T1 - Tn= and compensating transaction |
|||
=C1 - C(n-1)= where the following guaranteed: |
|||
|
|||
- The transactions will commit in the order =T1...Tj=, =Cj...C1= (where =j < n=). |
|||
|
|||
So basically this means that a saga transaction is a seq of chained transactions which applies the |
|||
smaller transactions in order with their corresponding compensating transactions. |
|||
|
|||
In a chained transaction when ever transaction Tn aborts, the transactions before Tn stay committed, |
|||
but in saga transactions they will be rollback using compensating transactions that know how to |
|||
roll them back *logically*. |
|||
|
|||
So Saga transactions can be fix both multi-staging and bulk update problems. But the issue here is |
|||
that the compensating transactions are something that requires application level understanding of |
|||
the use case so most of the time they are implemented in the application frameworks instead of DBMSs. |
|||
@ -0,0 +1,63 @@ |
|||
#+SETUPFILE: ../config.org |
|||
#+OPTIONS: toc:2 |
|||
#+EXPORT_FILE_NAME: faq.html |
|||
#+DATE: 2021-02-11 |
|||
#+TITLE: FAQ |
|||
#+PAGE: true |
|||
|
|||
Here is a list of questions people usually ask me. |
|||
|
|||
* General |
|||
** Why your website is like this ? |
|||
I value simplicity. The purpose of this website is to share my thoughts and research with others and not |
|||
to impress them with a shiny and heavy good looking website. |
|||
** Where can I find your CV ? |
|||
You can find my CV [[https://dl.lxsameer.com/CV/SameerRahmani.pdf][Here]], I try to keep it up to date ( Not always though :D ). |
|||
** How do you keep up with your work and research ? |
|||
I use [[https://orgmode.org/][org-mode]] to manage my life mostly, But beside that I have priorities in my life and when things come to |
|||
my way I process them based on my priorities. For example I love to play the Guitar but as long as I have time for |
|||
it and it doesn't interfier with my priorities. |
|||
|
|||
I usually partition my days into chunks of two days time and dedicate the main goal of each chunks to a cetain |
|||
project that I have to work on. It makes the context switch less painfull. BTW I use [[https://orgmode.org/][org-mode]] to take notes and |
|||
track my progress in my research and project and also when I read books. |
|||
** What do you do for fun ? |
|||
Usually video games, Anime music and sports. |
|||
|
|||
* Engineering |
|||
|
|||
** What GNU/Linux distro do you use ? |
|||
I used to use Debian unstable for 14 years. But I moved to Gentoo just because I care about my security and I |
|||
hate Systemd. |
|||
|
|||
** What editor/IDE do you use ? |
|||
I use my own editor, [[https://devheroes.codes/FG42/FG42][FG42]] which is based on on the mighty [[https://www.gnu.org/software/emacs/][GNU/Emacs]] and publicly available under GPLv2 license. |
|||
|
|||
** What desktop environment/window manager do you use? |
|||
Again, I use editor [[https://devheroes.codes/FG42/FG42][FG42]] for that purpose as well. I boot directly into my editor and manage everything from there. |
|||
|
|||
** What's your favorite programming language ? |
|||
I don't have any bias toward any specific language, But I've found the Lisp family to be really good. |
|||
|
|||
** Have you studied Software engineering in college ? |
|||
No |
|||
|
|||
** How can I improve as an engineer ? |
|||
I'm not an advisor and frankly I'm somewhere in my own journey and far from the end. But I can give one piece of |
|||
advise. Whatever you do, try to be scientificly literate. |
|||
|
|||
** Where is your hang out place up on the internet ? |
|||
I'm an [[https://en.wikipedia.org/wiki/Internet_Relay_Chat][IRC]] user and I usually hang out in the irc://freenode.net/#5hit channel. |
|||
|
|||
|
|||
* Science |
|||
** What do you do in Science ? |
|||
Physics |
|||
** What is your field of study ? |
|||
Quantum field theory |
|||
** I though you're an engineer, What's your deal? |
|||
Well, I love physics. Simply I want to know more. The universe baffles me. |
|||
** What do you suggest to those who want to start in science ? |
|||
I'm not an advisor and even not a top notch scientist, So I can't give you any good advise, But I share my own |
|||
experience with you. The most important thing is to keep an open mind, always think like us humans are not |
|||
the center of universe and finally learn algebra. |
|||
@ -0,0 +1,15 @@ |
|||
#+SETUPFILE: ../config.org |
|||
#+OPTIONS: toc:nil |
|||
#+EXPORT_FILE_NAME: gpg.html |
|||
#+DATE: 2021-02-11 |
|||
#+TITLE: GPG Information |
|||
#+PAGE: true |
|||
|
|||
I use GPG heavily. There might be some expired or fake keys of mine on key servers but here is [[https://dl.lxsameer.com/lxsameer.pub.gpg][My Current Key:]] |
|||
|
|||
#+BEGIN_SRC |
|||
pub rsa4096 2020-01-03 [SC] [expires: 2022-01-02] |
|||
75B126C50711BF7F4816D451B775967058BB835C |
|||
uid [ unknown] Sameer Rahmani (For more info refer to: lxsameer.com) <lxsameer@gnu.org> |
|||
sub rsa4096 2020-01-03 [E] [expires: 2022-01-02] |
|||
#+END_SRC |
|||
@ -1,17 +1,23 @@ |
|||
#+SETUPFILE: ../config.org |
|||
#+OPTIONS: toc:nil |
|||
#+EXPORT_FILE_NAME: index.html |
|||
#+TAGS: ABD(a) BD(c) ASDK(k) |
|||
#+DATE: 2021-02-11 |
|||
#+CATEGORY: blah |
|||
#+TITLE: blah |
|||
#+TITLE: The little nest of mine |
|||
#+PAGE: true |
|||
|
|||
* Welcome :ABD:BD: |
|||
:PROPERTIES: |
|||
:BLAH: s |
|||
:END: |
|||
blha bbasd asds asd a asd =asdasd= somer `asdasd` sadasd *asdasD* asdasd /asdasd/ asdasd. |
|||
ads ad asd asd as dasd asd |
|||
- [[http://localhost:3003/essays/serene-blah.html][Serene blah]] |
|||
- [[http://localhost:3003/essays/javascript-blah.html][javascript blah]] |
|||
Welcome to my little piece of the world. I'm a software engineer by day and an armature scientist by night |
|||
who lives by his [[./coh.org][Code of Honor]]. I write about my thoughts and researches. The views expressed here are my |
|||
personal views and not of those organizations that I might be associated with. Most of my time goes to developing |
|||
free software either by contributing to other projects or by working on my own stuff which you can find |
|||
them on [[https://devheroes.codes][devheroes]]. |
|||
|
|||
If you're interested in my work and research feel free to contact me to have a friendly chat Or share you thoughts |
|||
with me via email (check my [[./gpg.org][GPG]] info page). If you have a question for me, you might be able to find the answer to it |
|||
in the [[./faq.org][FAQs]] page. |
|||
|
|||
* Recent updates: |
|||
- [[http://localhost:3003/essays/serene-simple-version.html][Serene (simple versoin)]] |
|||
- [[http://localhost:3003/essays/choosing-the-target-platform.html][Choosing the target platform]] |
|||
- [[http://localhost:3003/essays/rational-and-a-name.html][Rational and a name]] |
|||
- [[http://localhost:3003/essays/my-new-programming-language.html][My new programming language]] |
|||
- [[http://localhost:3003/essays/transaction-variants.html][Transaction Variants]] |
|||
|
|||
@ -1,12 +1,22 @@ |
|||
#+TITLE: lxsameer's nest |
|||
|
|||
- [[file:essays/serene-simple-version.org][Serene (simple versoin)]] |
|||
- [[file:essays/choosing-the-target-platform.org][Choosing the target platform]] |
|||
- [[file:essays/rational-and-a-name.org][Rational and a name]] |
|||
- [[file:tags/Serene.org][Serene]] |
|||
- [[file:tags/Languages.org][Languages]] |
|||
- [[file:essays/my-new-programming-language.org][My new programming language]] |
|||
- [[file:categories/Engineering.org][Engineering]] |
|||
- [[file:tags/Databases.org][Databases]] |
|||
- [[file:essays/transaction-variants.org][Transaction Variants]] |
|||
- [[file:faq.org][FAQ]] |
|||
- [[file:gpg.org][Code of Honor]] |
|||
- [[file:coh.org][Code of Honor]] |
|||
- [[file:categories/nil.org][<<<title>>>]] |
|||
- [[file:categories/SLA.org][SLA]] |
|||
- [[file:tags/ASDK.org][ASDK]] |
|||
- [[file:tags/BD.org][BD]] |
|||
- [[file:tags/ABD.org][ABD]] |
|||
- [[file:essays/javascript-blah.org][javascript blah]] |
|||
- [[file:tags/index.org][index]] |
|||
- [[file:categories/index.org][index]] |
|||
- [[file:essays/serene-blah.org][Serene blah]] |
|||
- [[file:index.org][blah]] |
|||
@ -1,16 +1,19 @@ |
|||
#+SETUPFILE: ../config.org |
|||
#+OPTIONS: toc:nil |
|||
#+EXPORT_FILE_NAME: index.html |
|||
#+TAGS: ABD(a) BD(c) ASDK(k) |
|||
#+DATE: 2021-02-11 |
|||
#+CATEGORY: blah |
|||
#+TITLE: blah |
|||
#+TITLE: The little nest of mine |
|||
#+PAGE: true |
|||
|
|||
* Welcome :ABD:BD: |
|||
:PROPERTIES: |
|||
:BLAH: s |
|||
:END: |
|||
blha bbasd asds asd a asd =asdasd= somer `asdasd` sadasd *asdasD* asdasd /asdasd/ asdasd. |
|||
ads ad asd asd as dasd asd |
|||
Welcome to my little piece of the world. I'm a software engineer by day and an armature scientist by night |
|||
who lives by his [[./coh.org][Code of Honor]]. I write about my thoughts and researches. The views expressed here are my |
|||
personal views and not of those organizations that I might be associated with. Most of my time goes to developing |
|||
free software either by contributing to other projects or by working on my own stuff which you can find |
|||
them on [[https://devheroes.codes][devheroes]]. |
|||
|
|||
If you're interested in my work and research feel free to contact me to have a friendly chat Or share you thoughts |
|||
with me via email (check my [[./gpg.org][GPG]] info page). If you have a question for me, you might be able to find the answer to it |
|||
in the [[./faq.org][FAQs]] page. |
|||
|
|||
* Recent updates: |
|||
<<<links>>> |
|||
|
|||
Loading…
Reference in new issue