fc1.go

package main

import (
    "fmt"
    "io/ioutil"
)

// FileSystem is the facade interface
type FileSystem interface {
    ReadFile(string) ([]byte, error)
    WriteFile(string, []byte, int) error
}

// FileSystemImpl is the struct that implements the facade interface
type FileSystemImpl struct{}

func (fs *FileSystemImpl) ReadFile(path string) ([]byte, error) {
    return ioutil.ReadFile(path)
}

func (fs *FileSystemImpl) WriteFile(path string, data []byte, perm int) error {
    return ioutil.WriteFile(path, data, perm)
}

func main() {
    var fs FileSystem = &FileSystemImpl{}
    data, _ := fs.ReadFile("test.txt")
    fmt.Println(string(data))
    fs.WriteFile("test.txt", []byte("Hello, World!"), 0644)
}