AntonStoeckl

if nilCommand != nil {
	_ = nilCommand.CommandType()
}

AntonStoeckl

package commandhandling

// ConfirmEmailAddress implements the Command interface
type ConfirmEmailAddress struct {
	commandType string
	// some useful properties
}

func NewConfirmEmailAddress() *ConfirmEmailAddress {
	return &ConfirmEmailAddress{

AntonStoeckl

package commandhandling

import (
	"errors"
)

var ErrCommandIsNilInterface = errors.New("command is nil interface")
var ErrCommandIsNilPointer = errors.New("command is nil pointer")
var ErrUnknownCommand = errors.New("unknown command received")

AntonStoeckl

package commandhandling_test

import (
	"testing"

	"github.com/matryer/is"

	"go-bits/interfaces-and-nil/commandhandling"
)

AntonStoeckl

package factorial

func PositiveFactorial(number uint8) uint {
   if number == 0 {
      return 1
   }

   result := uint(1)

   for n := uint8(1); n <= number; n++ {

AntonStoeckl

package cars

import (
   "errors"
)

// For the sake of this example I simply use alias types for the of Car

type ID string
type CarMake string

AntonStoeckl

func (c *Cars) FilterSportscarsV2() []*Car {
   var sportscars []*Car

   for id, car := range c.items {
      hasEnoughHorsepower := car.Horsepower > sportscarsMinHorsepower
      hasSportyMake := car.CarMake == sportscarsMake
      hasASportyColor := car.Color == sportscarsColor

      if hasEnoughHorsepower && hasSportyMake && hasASportyColor {
         sportscars = append(sportscars, car)

AntonStoeckl

type Handler interface {
   ServeHTTP(ResponseWriter, *Request)
}

AntonStoeckl

func (h *SomeHandler) (w ResponseWriter, r *Request) {
   // ...
}

AntonStoeckl

package basics

// IsBigger is a plain function that compares two integers
// and return true if the first is bigger than the second ;-)
func IsBigger(first, second int) bool {
   return first > second
}

// Compare is a higher order function that compares two integers via a function
// that is passed in as the third parameter using explicit annotation,