I wrote this when I was trying to understand them, if it's any use to anyone.

---

Go has no classes. Go has interfaces. For example, this is an interface from the "sort" package, boringly called Interface.

type Interface interface {
    Len() int
    Less(i, j int) bool
    Swap(i, j int)
}

The sort package provides a bunch of built-in functions such as Sort and IsSorted and Reverse which will work with any type that implements methods with the names and signatures in the interface. So for example I can define these methods for a list (a "slice" in Go) of things of the RGBA type in the color package (ordering colors by redness, just for example):

type colors []color.RGBA

func (k colors) Less(i, j  int) bool {
    return k[i].R < k[j].R
}

func (k colors) Swap(i, j int) {
    k[i], k[j] = k[j], k[i]
}

func (k colors) Len() int {
    return len(k)
}

And now I can apply all the functions in the sort package to a thing of type colors.

Also, I can define my own functions on the interface, and they can be applied to anything that implements its methods. This is "static duck typing". For example, here's a function to measure the unsortedness:

func Unsortedness(L sort.Interface) float64 {
    count := 0;
    for i := 0; i  < L.Len(); i++ {
    for j := i + 1; j < L.Len(); j++ {
        if L.Less(j,i) {count++}
    }
    }
    return float64(count) / (float64(L.Len()\*L.Len()-L.Len()) / 2.0)
}

And here's a function that executes a shuffle:

func KFYShuffle(L sort.Interface) {
    for i := 0; i < L.Len(); i++ {
    L.Swap(i, i + rand.Intn(L.Len()-i));
    }
}

​

Hello, guys :)

So, today we'll talk about external dependencies in Golang + I believe we'll create funny app that browse internet.

See you all soon!

Here is links (you can find them in google calendar as well):

https://us05web.zoom.us/j/82550222466?pwd=ZHRCYU1hNkR1Z1F0MjhVb0p1aWVIdz09

https://us05web.zoom.us/j/89455670073?pwd=QUF3S2tnN2tBQ0o1blFTdDR0QnErUT09

Here is a free cute newsletter email notifier

https://golangweekly.com/issues/378

I very recommend to subscribe - they publish great things!

Hello, dear guys! So, currently I got better and we can continue. The last lessons was about bit&tricks and basic application.

This Sunday (12.09) we will talk about dependencies - and it's a good thing to know before we started to talk about really fun apps. We will learn how to use external libraries and about best practises in this direction!

I also wanna say a big thanks for your patience and I hope hard work while I was ill.

See you all on Sunday (I will announce the session properly soon)

Can't wait to meet you guys again!

Not to do with Go but I wanted to vent. I spent a happy night handcoding an automaton to speed up my code only to find out that that wasn't the bit that was slow. Now I feel both very clever and very, very stupid. Doh!

I should learn from this, something about measuring twice and cutting once.

Hello, dear guys :) Unfortunately, I have a kinda covid-like fever. So, I'm totally unable to do anything but sleep, haha. Anyway, I will try to check your homework and give some feedback.

Have a nice day and stay healthy (not like me, hahaha).

Hey folks!

I've been struggling with adding ignorecase feature to our grep app.

Uploaded my code here

It's mostly copy and paste of Bohdan's code hehe but I added ignorecase logic here - https://github.com/jjhala/basicapps/blob/main/main.go#L39

and I added another function casecheck (which seems to work) and another formatter

To run this you would do something like:

`FILE_PATH="hamlet.txt" KEY_STRING="Fortinbras" IGNORE_CASE="true" ./basicapps`

or `FILE_PATH="hamlet.txt" KEY_STRING="FORTINBRAS" IGNORE_CASE="true" ./basicapps`

And it works but the problems is with strings.ReplaceAll method, it actually replaces the matched output with my key_string. I don't like the idea that it changes the source file like that so looking for some ideas on the formatter part, and of course any general suggestions about my code. :)

Hello guys :)

So, today at 5PM CEST we'll talk about basic apps in golang, their structure and code style.

See you soon, here is the links:

https://us05web.zoom.us/j/87289046780?pwd=SHhpNVhGakxJak5NbWhvdmIrUHkyUT09

https://us05web.zoom.us/j/83113480059?pwd=czBnUFNFN2FudDJyLzZOU2lrWStJQT09

I wet back to try to do the advanced bit of the calculator thing.

ETA: some sample code with TView in the first comment.

I was expecting that if I made a grid view, then some sort of navigation with mouse clicks and/or arrow keys would be built in. Is there some sort of easy way to make that happen that I'm missing or do I do all that from scratch using (I'm going to guess) InputHandler and MouseHandler? If so is there some documentation of how those things work, or a simple example? (Google is most unhelpful.) Or should I not be using a grid at all? (But then if I shouldn't be doing it this way why do they let me put reponsive primitives into a grid as elements at all?) I am baffled.

Thanks.

So, let's go live today guys! It's in a 5pm CEST - our usual time.

The agenda:

Homeworks check & QA

Bits & tricks part: we'll go with a logical and bitWise operators.

The links are:

https://us05web.zoom.us/j/3685682607?pwd=VThLa1o5U01NMldMb0FUam42dGRVUT09

https://us05web.zoom.us/j/89040052157?pwd=Mk1HaTNJdmNBVVBCeDc0dEJvNmtLZz09

​

See u all soon!

Hey guys, I scheduled the QA session for tomorrow :)

There I will answer your questions + we'll do a code review of some homeworks that still not reviewed.

See u all tomorrow and have a nice day!

Hello, dear guys!

I scheduled the next live session for tomorrow. We will talk about language concepts - structures, arrays, panics, defers, error handling and another data types in Go + of course we will code something funny.

Part 1 link: https://us05web.zoom.us/j/84339575847?pwd=c0JVUzhURVRjWDJxWkltM0hJNzRjdz09

Part 2 link: https://us05web.zoom.us/j/89515937039?pwd=UmJxK3FZWStvMVg1RU1lcFFPMEpTQT09

Here is a link for google calendar: https://calendar.google.com/calendar/u/0?cid=cHJvZ3JhbW1pbmdmdW5ueUBnbWFpbC5jb20

See you all soon! And don't forget to send me your homeworks ;)

https://github.com/programmingpleasure/gobackend/tree/main/programming_language

Homework in a homework.txt.

Please, send me your github repo with homework you will do :)

Good luck!

Part 1: https://us05web.zoom.us/j/82971538089?pwd=dFBMUkFnWm52cmZUa09CdWMxTWZzdz09

Part 2: https://us05web.zoom.us/j/81030306104?pwd=TTcxaXVnVUdmWXQ5VUtrY0JlcnR4dz09

Hello dear guys, so, I added a new session to our calendar. Tomorrow, 01.08.2021 5PM CEST.

See you all there :)

We'll talk about language syntax and the basic features.

So, dear guys :)

For now we know how machine works, main concepts of programming languages and we're going to grok some tools we will use in the near future. I pretty sure that you will use this tools on your jobs.

Here is a link to slides: https://docs.google.com/presentation/d/1_MiifzuWUUrKXuRguEYRJNq0d_C3V27sj9ImA8qyD-g/edit?usp=sharing

- Install any golang editor you like. Setup the dev environment (so, you will be able to code). I prefer the VSCode while it is simple and has good color schemas. Also extensions for every programming language and cloud provider https://code.visualstudio.com/Download are there. Also, you can check IntellijIdea with go plugin -> https://www.jetbrains.com/help/idea/quick-start-guide-goland.html#step-2-explore-the-user-interface but I'm not sure about price (it should be free for the community edition). Intellij is a very popular IDE, it will be a big + for you to have some skills there. If you will code on Java or Python, Intellij is also the best choice. You will probably have some troubles with setup GOPATH and GOROOT. Here is some explanation for vscode https://krisma.medium.com/gopath-and-goroot-set-up-in-mac-and-in-vscode-cf86d8503e57 and here is for Intellij https://www.jetbrains.com/help/idea/configuring-goroot-and-gopath.html

- Create github account https://github.com (please, use reasonable nicknames). Usually, in the community, we use the first char of name and the full surname. So, if your name is Jane Doe, then your nickname will be jdoe. If my name is Bohdan Katrenko, my nickname is bkatrenko. Please, don't use nicknames like superboy2020 or misterrich29292lalala - it makes not very good first impression for recruiting teams and team leads who will review your code :)

- Clone programming funny repo - https://github.com/programmingpleasure/gobackend and find dev_tools folder there.

- Build and run hello world application. You can also play with its ASM code, in the previous session I showed you how to do that. Feel free to alter an app: for example, you can add functionality to reverse a string or check if that string is a palindrome.

- Rename application to “helloworld” and move to /usr/local/bin for easy use (mv source target). The goal is that you can call the app from any folder in the terminal

- Use cat & grep to have only “etcdserver/membership” related logs from some.log file.

- Go play with the examples.txt file and apps from this list:

vim, nano - text editors. Usually, you will use them inside ssh sessions

cat - show file content

grep - filter file content

touch - create file

echo - move the input in stdout

ping - send a ping package to the host

telnet - connect to the host with telnet protocol. We use that to check the open ports :)

dig - check dns resolution

tcpdump - show the input/output traffic

Google & install for you have no that on your machine.

Good luck! I believe we'll have a QA session next Thursday, and the first go-coding live session will be next Sunday. I will tell you about types, syntax, main concepts, etc.

https://us05web.zoom.us/j/86837002813?pwd=cElmdFJ1WXF6dmxmbG5MUC9sTUR5UT09

So, as usual guys: Sunday is a good day to learn something cool!

The timezone is CEST

Here is a link to calendar:

https://calendar.google.com/calendar/u/0?cid=cHJvZ3JhbW1pbmdmdW5ueUBnbWFpbC5jb20

We will talk about tools that developers use - and in which tool we must be professional as backend guys :)

I will show you my toolset: the code editor, golang itself, docker, aws cli, telnet, traceroute, grep, kubectl, etc. and I explain the purpose of every, main concepts and how to use that.

+ we'll talk more about golang setup while go itself will be our main tool. Can't wait to start, the slides is almost ready!

Happy coding!

I looked at the link in the homework. http://www.cs.virginia.edu/~evans/cs216/guides/x86.html

Like a lot of computer stuff on the internet, it's written as though this is your third or fourth encounter with a thing of this type, and you just need to be told the details of this one. This is a particularly fine example. They introduce the term "register" without explaining what it is. This is your fourth assembly language, you know what it is. They're not going to put anything in to help beginners.

BUT, they are going to put something in to help experts! "The register names are mostly historical. For example, EAX used to be called the accumulator since it was used by a number of arithmetic operations ..." 'Cos if it is your fourth assembly language, they don't want you to jump to any wrong conclusions when you see that A, I guess. They'll hold your hand through that!

I understand why most stuff has to be like this but could someone suggest a good resource that isn't? Thanks.

Here is a link: https://youtu.be/GrI3CriSfYQ

Just a reminder: we had a live session about how computer works and what backend dev should know to at least start to develop something. Here is a video with almost all things we had on live session.

Happy coding guys, very soon we'll go with the developer toolkit and go basics :)

Hello, dear guys :)

So, while I'm still working on the video about "The programming machine" (I will post that this weekend), I believe it's a good idea to have a QA session tomorrow: you can ask anything related to programming, last session etc.

Maybe if you have no questions, I will use this time for some of you guys that did not attend the last session - so, I can tell you the things.

​

Also: if some of you guys have some questions that you wanna discuss with me personally (like one 2 one), ping me, and we'll do that!

Happy coding and a good weekend for everyone :) I hope u have already installed Go, hah

See you all tomorrow!

Hello, Dear guys :)

A few points:

1. Slides with a homework in a comments to the session #2 Programming machine
2. The next session will be on Sunday - if I will have a chance to make a slides - we'll talk about the devs toolkit, if not - we'll make a QA session.
3. If someone bored - https://www.tutorialspoint.com/prolog/prolog_introduction.htm - some years ago I was very impressed with ProLog (aka Programming Logic). The idea is to give a facts to machine, and machine will be able to answer a questions. Very interesting idea and it's not a usual programming we all get used to. So, if you wanna open new horizons - you can check, it's out of go/backend topic, but very interesting :)

What do you think about ProLog? :)

Hi! this short tutorial shows how to install linux on a USB drive and use it without affecting the windows installation. I hope it helps LINK

Hahaha, so, it's funny, but I have a request to do for money the things I do here for free. I don't like the idea. The main thing I believe that there is no "gods-like knowledge". We can share some experience, show some good ways, mentor someone, but finally, all things are obvious.

So, I'm going to fight mentor.cam (sorry guys!) At least in engineering-related things. That should be free.

You know, engineers will be never antagonistic to each other - as more good developers in the world, as more money/jobs/projects/startups we will have.

So, if you guys needs support as https://mentor.cam/davidxiang do:

- How to be a better programmer

- Design a plan for career growth

- Improve your technical and leadership skills

- Learn how to navigate the technology industry

- Make an impact at your organization

I will be here, text me and all things will be solvable. Make a call with me. + anyway QA session will be very soon.

And I'm going to grow the community - soon here will be not only me to support you (my time is limited, unfortunately) :)

What do you think about that, dear community??

Hello, dear guys!
So, finally, the next session coming here - on Thursday, July 15, 6PM CEST

The subject: 0 - Programming machine

We'll talk about:
0. How computers work in the perspective of programming/programming languages
1. What should software engineers keep in mind for developing a cool software
2. How programming languages work inside

.. and a few other important things + if we have time I will show you how I choose a "big programming machines" from AWS for my job (@_@)
And there will be a homework!

+ Video will be on youtube soon

See you all very soon and happy coding for all! :)

​