Go Language¶

YAML Time Duration Support in Go

Last time, when one of users asked me "could I set up a 100d in his yaml file for Go time.Duration", my first action is why he cannot search the documentation by himself. But then, another problem overwhelmed my mind because actually I'm not sure about it. I don't know it as well.

After seeing the source code, I got the answer. However, the important inspiration here is: "how to make knowledge cohesive", hence the blog comes. In short, you should understand several concepts here:

• whether the time duration is a standard specification?
• does Go implementation allow to parse a string into different type?
• how could it parse?

By enquiring these questions progressively, you can easily recognize how yaml works in a cohesive way instead of remembering some scattered knowledge about it.

Go: log.Fatalf is Bad for Framework Maintainers

In the open source framework, as long as maintainers can ensure the issues are caused by users instead of the framework, usually they could provide some suggestive guides and prevent themselves from delving into users code.

However, as a company scope framework maintainer, things differ greatly. As you claimed your framework helps them to write better code based on the company platforms, they're likely to rely on the maintainers to figure out some weird issues once it's related with the framework.

This blog records how I help to trouble shoot the weird issue of keeping restarting and failed to deploying caused by the log.Fatalf for our framework users, and my opinion why the log.Fatalf is bad.

Go Reflect: Correctly Get an Empty Interface Type

This blog records the tricky part of using reflect to get an empty interface type correctly. The background is that a component requires the configuration type during function call as it might use the type to construct a type and set up the value based on some external data set. If we cannot find a respective in some scenarios, empty interface type should be passed.

However, at the beginning due to the wrong usage of reflect, a nil type instead of interface{} type is passed by reflect.TypeOf(i).

var i interface{}
// this is correct
typ := reflect.TypeOf(&i).Elem()

// this is wrong usage, the typ is nil
typ := reflect.TypeOf(i)

Router in Gin

Given a URL /api/users/1234/pages, how an HTTP server finds the corresponding handler for it? Router helps to convert the concrete URL to a pattern and its handler.

This blog introduces the routers in Gin framework. In short, Gin uses trie(prefix tree) to maintain the URL-handler mapping.

Errcheck Linter Implementation

Recently, I'm going to develop a static tool to analyze our self-defined framework syntax inside our company. Hence, I investigated a lot around the open source linters to find some ideas. This blogs talks about the implementation of errcheck. It's based on AST and relies on the node types to handle the different cases.