refactor: common ifaces

interfaces/13-io/json.go

@@ -0,0 +1,59 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"io/ioutil"
+	"os"
+)
+
+func encode() ([]byte, error) {
+	l := list{
+		{Title: "moby dick", Price: 10, Released: toTimestamp(118281600)},
+		{Title: "odyssey", Price: 15, Released: toTimestamp("733622400")},
+		{Title: "hobbit", Price: 25},
+	}
+
+	return json.MarshalIndent(l, "", "\t")
+}
+
+func decode(data []byte) (l list, err error) {
+	if err := json.Unmarshal(data, &l); err != nil {
+		return nil, err
+	}
+	return l, nil
+}
+
+func decodeFile(path string) (list, error) {
+	// ReadAll reads entire bytes from a file to memory.
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return decode(data)
+}
+
+func decodeFileObject(f *os.File) (list, error) {
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+	return decode(data)
+}
+
+func decodeReader(r io.Reader) (l list, err error) {
+	// data, err := ioutil.ReadAll(r)
+	// if err != nil {
+	// 	return nil, err
+	// }
+	// return decode(data)
+
+	return l, json.NewDecoder(r).Decode(&l)
+}