GoLang

Introduction

Purpose:

• backend application

• compile fast, run fast

• high level, user friendly

Install:

• install go described on their website

• install go VSCode extension

• follow the instruction when you open a go project in VSCode, install gopls. It is the official Go language server developed by the Go team to enable you to do auto complete, go to definition, or documentation on hover for a programming language.

When you first have a project, you do go mod init [name]. This will create a file like the following:

module test

go 1.16

And in main.go, we write

package main // which package this file belong to

import "fmt" // import package

func main() {
  fmt.Print("Hello World")
}

To execute, we do go run main.go

Go Syntax

For more, see Test

Next Step

Here are some useful links:

• Go Documentation

• Project Structure for Big Project

• Standard Libraries

• Language Spec

• Go Concurrent Pattern (Youtube)

• Advanced Go Concurrent Pattern (Youtube)

• Shared Memory By Communication

• Web Programming Environment (Vimeo)

• Writing Web Applications

Warnings

Note that when printing pointers with fmt library, it might not print the value of pointer (ie. the address) but it might print what the pointer is pointing to (ie. the struct). Consider the following code:

type Stuff struct {
    X int
}

func main() {
    p := &Stuff{1}
    fmt.Println(p)
}

It will print out &{1}. This is because fmt.Println(p) is the same as fmt.Printf("%v\n", p).

To print the address, you can do

p := &Stuff{1}
fmt.Printf("%p\n", p)

You can run go with go -race flag to check for race condition. You can run go fmt to auto format code in directory. You can install multiple versions of go following this guide

Checking Goroutine Leak

import (
  "go.uber.org/goleak"
)
func TestMain(m *testing.M) {
  goleak.VerifyTestMain(m)
}