Learning Go Episode 2 – Further into packages, dependencies, application creation, and IDE’s

Episode Post & Video Links:  1, 2 (this post), 3, 4, 5, 6, 7, and 8. Non-linked are in the works! Videos available now on Youtube however, so check em’ out!

In episode two I went over a lot of the material that I covered in the first episode, but added more context, historical reasons certain things are the way they are in Go and the stack, and went over a number of new elements of information too. One thing I got further into this episode is the package and dependency management with Go Dep and also how to create a package, or dependency library for use in other Go libraries or applications. It’s just a small introduction in this episode, but pivotal to future episodes, as I’ll be jumping further into library creation and related details.

In this post I’ve got the time point breakdown like usual,  but also a few additional bits of information and code examples, plus links to the repository I’ve setup for this particular episode. The quick links to those references are below, and also I’ll link at particular call out points within the time points.

Quick Links:

Key Topics Covered

Data Types, Packages, and Dependency Management

2:52 – Fumbling through getting started. It is after all Saturday morning!
3:00 – Recap of what we covered in the first session. Includes a quick review of the previous session code too, such as the random data generation library we setup and used.
6:40 – Covering some specifics of the IDE’s, the stories of the benefits of Go having a specific and somewhat detailed convention to the way syntax, variables, and related features are used.
7:40 – Covering gofmt and what it gives us.
9:45 – Looking at the gofmt plugins and IDE features around the conventions.
14:06 – New example time! In this one, I work through an example showing how to find duplicate lines in passed in text.

Duplicate Line Finder

I went through the various steps of creating the code, but then took a little bit of a detour from the example in the book. Instead of lines by the CLI it takes in content from a text file. The code in main.go ended up like this.

package main
import (
"bufio"
"fmt"
"os"
)
func main() {
counts := make(map[string]int)
files := os.Args[1:]
if len(files) == 0 {
countLines(os.Stdin, counts)
} else {
for _, arg := range files {
f, err := os.Open(arg)
if err != nil {
fmt.Printf("The Error Happened! %s", os.Stderr)
continue
}
countLines(f, counts)
errFile := f.Close()
if errFile != nil {
fmt.Println("Holy moley the file didn't close correctly!")
}
}
}
for line, n := range counts {
if n > 1 {
fmt.Printf("%d\t%s\n", n, line)
}
}
}
func countLines(f *os.File, counts map[string]int) {
input := bufio.NewScanner(f)
for input.Scan() {
counts[input.Text()]++
}
}

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main.go

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Then if you’d like to check out the text file and remaining content in that project, check out the master branch of the episode 2 repo.

36:34 – Here I take a thorough step through committing this project to github, which is the included repo in this post. However I step through the interface of using Jetbrains Goland to do the commit, how it enables gofmt and other features to improve the condition of code and ensure it meets linter demands and related crtieria. I also cover the .gitignore file and other elements to create a usable repository.
44:30 – Setting up the repository for today’s code at https://github.com/Adron/learning-go-…
50:00 – Setup of the key again for using Github. How to setup your ssh keys using ssh-keygen.
56:00 – Going beyond just the language, and building out a Go build on Travis CI.
1:10:16 – Creating a new branch for the next code examples and topics. At this point I shift into type declarations. Working through some constants, very basic function declarations, and related capabilities to calculate temperatures between Fahrenheit and Celsius.

The tempApp Branch is available in the repository here.

At this point I shift into type declarations. Working through some constants, very basic function declarations, and related capabilities to calculate temperatures between Fahrenheit and Celsius.

During this point, we take a look at our first package. This package ended up looking like this.

package tempconv
type Celsius float64
type Fahrenheit float64
const (
AbsoluteZeroC Celsius = 273.15
FreezingC Celsius = 0
BoilingC Celsius = 100
)
func CelsiusToFahrenheit(c Celsius) Fahrenheit {
return Fahrenheit(c*9/5 + 32)
}
func FahrenheitToCelsius(f Fahrenheit) Celsius {
return Celsius((f 32) * 5 / 9)
}

In the main.go file, I showed how you can use this package by adding a respective import shown in this code.

package main
import (
"fmt"
tempconv "github.com/Adron/awesomeProject/tempconv"
)
func main() {
fmt.Println("Temperatures are hard to figure off the top of one's mind!")
boilingF := tempconv.CelsiusToFahrenheit(BoilingC)
fmt.Printf("%v\n", boilingF)
fmt.Printf("%s\n", boilingF)
fmt.Println(boilingF)
fmt.Printf("%g\n", boilingF)
}

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main.go

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1:17:54 – At this point, to increase readability of font sizes I get into the various Goland IDE options.
1:38:12 – Creating the final branch for this session to pull in a public package and use it in project. For this, I pull in a random data generation package to use in some application code.

package main
import (
"fmt"
randomdata "github.com/Pallinder/go-randomdata"
)
func main() {
// Print a random silly name
fmt.Println(randomdata.SillyName())
// Print a male title
fmt.Println(randomdata.Title(randomdata.Male))
// Print a female title
fmt.Println(randomdata.Title(randomdata.Female))
// Print a title with random gender
fmt.Println(randomdata.Title(randomdata.RandomGender))
// Print a male first name
fmt.Println(randomdata.FirstName(randomdata.Male))
// Print a female first name
fmt.Println(randomdata.FirstName(randomdata.Female))
// Print a last name
fmt.Println(randomdata.LastName())
// Print a male name
fmt.Println(randomdata.FullName(randomdata.Male))
// Print a female name
fmt.Println(randomdata.FullName(randomdata.Female))
// Print a name with random gender
fmt.Println(randomdata.FullName(randomdata.RandomGender))
// Print an email
fmt.Println(randomdata.Email())
// Print a country with full text representation
fmt.Println(randomdata.Country(randomdata.FullCountry))
// Print a country using ISO 3166-1 alpha-2
fmt.Println(randomdata.Country(randomdata.TwoCharCountry))
// Print a country using ISO 3166-1 alpha-3
fmt.Println(randomdata.Country(randomdata.ThreeCharCountry))
// Print BCP 47 language tag
fmt.Println(randomdata.Locale())
// Print a currency using ISO 4217
fmt.Println(randomdata.Currency())
// Print the name of a random city
fmt.Println(randomdata.City())
// Print the name of a random american state
fmt.Println(randomdata.State(randomdata.Large))
// Print the name of a random american state using two chars
fmt.Println(randomdata.State(randomdata.Small))
// Print an american sounding street name
fmt.Println(randomdata.Street())
// Print an american sounding address
fmt.Println(randomdata.Address())
// Print a random number >= 10 and < 20
fmt.Println(randomdata.Number(10, 20))
// Print a number >= 0 and < 20
fmt.Println(randomdata.Number(20))
// Print a random float >= 0 and < 20 with decimal point 3
fmt.Println(randomdata.Decimal(0, 20, 3))
// Print a random float >= 10 and < 20
fmt.Println(randomdata.Decimal(10, 20))
// Print a random float >= 0 and < 20
fmt.Println(randomdata.Decimal(20))
// Print a bool
fmt.Println(randomdata.Boolean())
// Print a paragraph
fmt.Println(randomdata.Paragraph())
// Print a postal code
fmt.Println(randomdata.PostalCode("SE"))
// Print a set of 2 random numbers as a string
fmt.Println(randomdata.StringNumber(2, "-"))
// Print a set of 2 random 3-Digits numbers as a string
fmt.Println(randomdata.StringNumberExt(2, "-", 3))
// Print a random string sampled from a list of strings
fmt.Println(randomdata.StringSample("my string 1", "my string 2", "my string 3"))
// Print a valid random IPv4 address
fmt.Println(randomdata.IpV4Address())
// Print a valid random IPv6 address
fmt.Println(randomdata.IpV6Address())
// Print a browser's user agent string
fmt.Println(randomdata.UserAgentString())
// Print a day
fmt.Println(randomdata.Day())
// Print a month
fmt.Println(randomdata.Month())
// Print full date like Monday 22 Aug 2016
fmt.Println(randomdata.FullDate())
// Print full date <= Monday 22 Aug 2016
fmt.Println(randomdata.FullDateInRange("2016-08-22"))
// Print full date >= Monday 01 Aug 2016 and <= Monday 22 Aug 2016
fmt.Println(randomdata.FullDateInRange("2016-08-01", "2016-08-22"))
// Print phone number according to e.164
fmt.Println(randomdata.PhoneNumber())
// Get a complete and randomised profile of data generally used for users
// There are many fields in the profile to use check the Profile struct definition in fullprofile.go
profile := randomdata.GenerateProfile(randomdata.Male | randomdata.Female | randomdata.RandomGender)
fmt.Printf("The new profile's username is: %s and password (md5): %s\n", profile.Login.Username, profile.Login.Md5)
// Get a random country-localised street name for Great Britain
fmt.Println(randomdata.StreetForCountry("GB"))
// Get a random country-localised street name for USA
fmt.Println(randomdata.StreetForCountry("US"))
// Get a random country-localised province for Great Britain
fmt.Println(randomdata.ProvinceForCountry("GB"))
// Get a random country-localised province for USA
fmt.Println(randomdata.ProvinceForCountry("US"))
}

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main.go

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1:44:50 – Further discussion and explanation of what to include in .gitignore files to manage projects, but also what is and isn’t included for dependencies and other details around all of this.
2:13:22 – The wicked awesome hacker outtro.

Learning Go Episode 1 – Environment, Go Workspace, GOPATH/GOROOT, Types, and more Introduction

Episode Post & Video Links:  1 (this post), 2, 3, 4, 5, 6, 7, and 8. Non-linked are in the works! Videos available now on Youtube however, so check em’ out!

This is episode one of a multi-part series on “The Go Programming Language“. Not necessary, but if you’d like to follow along you can also pick up the book “The Go Programming Language” by Alan A. A. Donovan and Brian W. Kernighan. At the bottom of the description I have a link to the book publisher’s website and the respective book. I’ll be using that as a guideline and using a number of examples from the book. However I’ll also be adding a lot of additional material around Goland IDE from Jetbrains and Visual Studio Code. The video link to this session is at the bottom of the post, scroll all the way down and it’s waiting for you there.

3:28 – Getting started, introducing that the session I’m starting with a completely new Ubuntu Linux load so that I ensure we cover all of the steps to get up and running. These steps, even though they’re on Linux are reproducible on Windows 10 and MacOS, so any operating system is usable to follow along with, with only minor discrepancies.

5:04 – Introducing the book that I’ll be using as a guideline reference so that viewers can also follow along with a physical book. I’m a big fan of multisensory learning, so between a book, the stream, being able to ask questions in the channel, it’ll give viewers a chance to learn and undertake their coding adventures in Go using all sorts of methods.

Book Reference: “The Go Programming Language” by Alan A. A. Donovan and Brian W. Kernighan

6:58 – Discussing where Go is located on the web related to Github and the golang.org site that is useful in that one can even try out little snippets of Go code itself, on the site!
Github: https://github.com/golang/go
Golang: https://golang.org
10:40 – Setting export in the .bashrc file (or .bash_profile on MacOS or environment variables on Windows 10). Speaking of Windows 10 specifically, Linda Gregier wrote up a great blog post on getting Go setup on Windows specifically.
14:50 – Setting up the Go workspace path for GOPATH using the standard Go convention. From here I get into the first “Hello World!” with Go.
15:34 – Mention of setting up Go on a Docker container and how it is easier, but we’re staying focused on setting it up completely from scratch.
18:20 – Starting first code, a standard “Hello World” program.
19:50 – First build of that “Hello World” program.
20:34 – Here I introduce go run and how to execute a singular file instead of building an entire project.
21:32 – Installing some IDE’s to use for developing Go applications. The first two up for installation is Visual Studio Code and JetBrains Goland.
29:00 – A first variable, what is it, and how to declare one in Go in one of the ways one can declare a variable in Go!
31:08 – Introducing the terminal in Visual Studio Code.
37:12 – A little example of OBS, how I’m using it, and how I interact back and forth with chat and related tooling plus the virtual machine itself.
42:36 – Changing themes and adding plugins for Goland. In the plugins I also find the most epic of status bars, the Nyan Cat!
59:00 – Here I start to get back into some more specific Go details. Starting off with a Go command line parsing application. At this point I also cover several additional ways to declare variables, speak more about short declarations, and other ways to declare, assign, and use variables in Go.

At this point I also go through a number of examples to exemplify how to go about declaring variables, build, run, and explore the details of the code. Further along I also get into string formatting, concatenating, and related string manipulation with Go.

Other details include taking a look at extra ways to figure out Go code using autocomplete inside Goland and other exploratory features. Eventually before wrapping up I broach pointers, tuple declaration techniques, and how to declare additional functions beyond func main().
1:58:40 – Adding dependencies and generating random data. At this point I bring in a dependency. But before pulling in the dependency, after introducing it, I show how to go about doing.
2:00:10 – New machine, and I run into git not being available. The go get command uses git to pull dependencies so I go about why this is needed and the steps to install on Ubuntu.
2:09:20 – Introduction to more concepts around dependencies, what go get does versus managing dependencies with Go Dep.
2:10:00 – Installing Go Dep; MacOS, using curl, Linux installation, and a question sort of remains to get it running on Windows. The easiest method is using chocolatey however, so check that out if you’re going the Windows route.
2:15:20 – Setting up Go Dep integration with Goland.
2:23:55 – Showing off Goland’s commit dialog and some of the respective options.