add: db.load and save

interfaces/14-io-reader/database.go

@@ -10,6 +10,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"reflect"
 )
 
@@ -18,14 +19,14 @@ type database struct {
 	types map[string]item // the registry of the types
 }
 
-// #v1
-// func (db *database) load(path string) error {
-// 	data, err := ioutil.ReadFile(path)
-// 	if err != nil {
-// 		return err
-// 	}
-// 	return json.Unmarshal(data, db)
-// }
+// load the list by decoding the data from a json file.
+func (db *database) load(path string) error { // #v1
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return err
+	}
+	return json.Unmarshal(data, db)
+}
 
 // #v2
 // func (db *database) load(r io.Reader) error {
@@ -39,28 +40,6 @@ type database struct {
 // #v3
 // TODO: use decoder
 
-// #v1
-// func (db *database) save(path string) error {
-// 	data, err := json.MarshalIndent(db, "", "\t")
-// 	if err != nil {
-// 		return err
-// 	}
-// 	return ioutil.WriteFile(path, data, 0644)
-// }
-
-// #v2
-// func (db *database) save(w io.Writer) error {
-// 	data, err := json.MarshalIndent(db, "", "\t")
-// 	if err != nil {
-// 		return err
-// 	}
-//
-//  return io.Copy(w, bytes.NewReader(data))
-// }
-
-// #v3
-// TODO: use encoder
-
 func (db *database) MarshalJSON() ([]byte, error) {
 	type encodable struct {
 		Type string