Hash Table using Go

hash_table.go

package main
import(
 "fmt"
 "math"
 "bufio"
  "os"
  "strings"
)
type HashEntry struct{
	value int
	key string
	next *HashEntry
}
type HashTable struct{
	hash_entries []HashEntry
	maximum int
}
func (self *HashTable) put(key string, value int) {
	// TO DO: Replace if key is the same
	position := hash(key,self.maximum)
	new_hash_entry := HashEntry{key: key, value: value}
	hash_entry := &self.hash_entries[position]
	if hash_entry.isNil(){
		self.hash_entries[position] = new_hash_entry
	}else {
		for hash_entry.next != nil {
		 	hash_entry = hash_entry.next
		}
		hash_entry.next = &new_hash_entry
	}
}
func (self *HashTable) get(key string) int{
	position := hash(key,self.maximum)
	hash_entry := self.hash_entries[position]
	for !hash_entry.isNil(){
		if hash_entry.key == key{
			return hash_entry.value
		}
		if hash_entry.next == nil{
			break
		}
		hash_entry = *hash_entry.next
	}
	return 0
}
func(self HashEntry) isNil() bool{
	return self.value == 0 && self.key == ""
}
func main() {
	var option,value int
	hash_table := HashTable{maximum: 20, hash_entries: make([]HashEntry, 20)}
Loop:
 	for true {
		fmt.Println("Elige una opción: \n1.- Ingresar al HashTable  \n2.- Leer del HashTable \n3.- Salir")
		fmt.Scan(&option)
		switch {
			case option == 1:
				text := getText("Clave a ingresar: ")
				fmt.Println("Numero para la clave")
				fmt.Scan(&value)
				hash_table.put(text, value)
			case option == 2:
				text := getText("Clave a buscar: ")
				fmt.Println(hash_table.get(text))
			case option == 3:
				break Loop
		}
	}
}
func getText(description string) string{
	reader := bufio.NewReader(os.Stdin)
	fmt.Println(description)
	text, _ := reader.ReadString('\n')
	text = strings.Replace(text,"\n","",-1)
	return text
}
func hash(data string,maximum int) int{
    h := 0;
    for _,c := range data{
      h = h + int(c)
    }       
    h = int(math.Abs(float64(h))) // Convert to positive if negative

    return h % maximum
}