Introduction Closures in Go are a very powerful construct but they can also be the cause of bugs if you don’t understand how they work. In this post I am going to pull a small piece of code from Chapter 2 from the Go In Action book that discusses a pitfall you can run into when using closures. The full code example can be found in the Github repository for the book.

Introduction My business partner Ed asked me what would happen if a struct and an embedded field both implemented the same interface. We asked ourselves two questions: Would the compiler throw an error because we now had two implementations of the interface? If the compiler accepted the type declaration, how does the compiler determine which implementation to use for interface calls? We hacked out some code to answer the questions and then I dug into the specification.

Introduction One of the more unique features of Go is how the language implements constants. The rules for constants in the language specification are unique to Go. They provide the flexibility Go needs at the compiler level to make the code we write readable and intuitive while still maintaining a type safe language. This post will attempt to build a foundation for what numeric constants are, how they behave in their simplest form and how best to talk about them.

Introduction One of the first things I learned about in Go was using an uppercase or lowercase letter as the first letter when naming a type, variable or function. It was explained that when the first letter was capitalized, the identifier was public to any piece of code that wanted to use it. When the first letter was lowercase, the identifier was private and could only be accessed within the package it was declared.

Introduction As I improve my knowledge and framework for a Go based web service I am building, I continue to go back and enhance my Beego Sample App. Something I just added recently was providing localized messages for validation errors. I was fortunate to find Nick Snyder's go-i18n package. Nick's package made it easy to support multiple languages for the Go web service I am writing. Abstracting go-i18n The go-i18n package is simple to use and you can use it to read files or strings that contain all the messages you want to localize.

If you are attending GopherCon 2014 or plan to watch the videos once they are released, this article will prepare you for the talk by Gustavo Niemeyer and Steve Francia. It provides a beginners view for using the Go mgo driver against a MongoDB database. Introduction MongoDB supports many different programming languages thanks to a great set of drivers. One such driver is the MongoDB Go driver which is called mgo.

Introduction In my last post called Concurrency, Goroutines and GOMAXPROCS, I set the stage for talking about channels. We discussed what concurrency was and how goroutines played a role. With that foundation in hand, we can now understand the nature of channels and how they can be used to synchronize goroutines to share resources in a safe, less error prone and fun way. What Are Channels Channels are type safe message queues that have the intelligence to control the behavior of any goroutine attempting to receive or send on it.

Introduction When new people join the Go-Miami group they always write that they want to learn more about Go’s concurrency model. Concurrency seems to be the big buzz word around the language. It was for me when I first started hearing about Go. It was Rob Pike’s Go Concurrency Patterns video that finally convinced me I needed to learn this language. To understand how Go makes writing concurrent programs easier and less prone to errors, we first need to understand what a concurrent program is and the problems that result from such programs.

Introduction We are working on a project where we have to make calls into a web service. Many of the web calls return very large documents that contain many sub-documents. The worst part is, we usually only need a handful of the fields for any given document and those fields tend to be scattered all over the place. Here is a sample of a smaller document: var document string = `{

Introduction In October 2013 I sent out a call to action to the Go community. I wanted to form a group of Gophers that would come together and help write a specification and build a working implementation of a package management tool. We are not there yet, but the group did accomplish a few things: We started a mailing list called Go package management [go-pm] where people could discuss ideas and get feedback on existing and new tools.