Golang: self-referential functions

selfref.go

// Original idea:
// http://commandcenter.blogspot.nl/2014/01/self-referential-functions-and-design.html
package main

import "fmt"

type Cat struct {
	Name string
}

func (c *Cat) SetName(opt CatOpt) CatOpt {
	return opt(c)
}

type CatOpt func(c *Cat) CatOpt

func Name(newName string) CatOpt {
	return func(c *Cat) CatOpt {
		previousName := c.Name
		c.Name = newName
		return Name(previousName)
	}
}

func main() {
	c := &Cat{Name: "Filemon"}
	fmt.Printf("%#v\n", c)
	prevName := c.SetName(Name("Marcin"))
	fmt.Printf("%#v\n", c)
	c.SetName(prevName)
	fmt.Printf("%#v\n", c)
}