행복한 은행 관리법

packagemydict

​

import(

"errors"

)

​

typeDictionarymap[string]string

​

var(

NotFound = errors.New("Not found")

errCantUpdate = errors.New("Can't update nonexistsing word")

errWordExists = errors.New("That word already exists")

)

​

func(d Dictionary)Search(word string)(string,error){

value, exits := d[word]

if exits {

return value,nil

}

return"", NotFound

}

​

func(d Dictionary)Add(word, def string)error{

_, err := d.Search(word)

if err == NotFound {

d[word]= def

}elseif err ==nil{

return errWordExists

}

returnnil

}

​

​

func(d Dictionary)Update(word, definition string)error{

_, err := d.Search(word)

switch err {

casenil:

d[word]= definition

case NotFound :

return errCantUpdate

}

returnnil

}

​

func(d Dictionary)Delete(word string){

delete(d, word)

}