Some personal reminders on Go development.

1) Perfect is enemy of good.

Often times is makes sense to keep going with a code idea. Write tests, so you can back out. But, if you have writers block… sometimes it helps to just code. Other options:

  1. Write next move with pen and paper - this helps with complex structures
  2. Review previous works of code - always helps to read other’s code

2) Interface Names (should be verbs)

Use verbs for interface names. Ref io.go, where names are WriteString, Reader, ByteWriter, Closer... Interfaces define function calls, so should be actions.

type Reader interface {
	Read(p []byte) (n int, err error)
}
...
type Writer interface {
	Write(p []byte) (n int, err error)
}

type Closer interface {
	Close() error
}

3) Select – Hate this about Go

The two programs below produce different results, based on where the “{“ is placed in the select.

Always false

package main

func False() bool {
	return false
}

func main() {
	switch False() {
	case false: println("False")
	case true: println("True")
	}
}
// Returns false

The above program will always return false. It does what you expect it to do.

Always true

package main

func False() bool {
	return false
}

func main() {
	switch False() // <<== Note "{" is no longer on this line
	{
	case false: println("False")
	case true: println("True")
	}
}
// returns true

But, the above program returns true, because it’s really formatted to be the following…

package main

func False() bool {
	return false
}

func main() {
	switch False(); {
	case false:
		println("False")
	case true:
		println("True")
	}
}

4 - Files relative

Reading files from relative directories doesn’t have to be difficult. Package runtime allows you to read in files relative to what directory you code is running in…

import (
	"path/filepath"
	"runtime"
)

var basepath string

func init() {
	_, currentFile, _, _ := runtime.Caller(0)
	basepath = filepath.Dir(currentFile)
}

func Path(rel string) string {
	if filepath.IsAbs(rel) {
		return rel
	}

	return filepath.Join(basepath, rel)
}