Create factory_method.go

creational/factory_method.go

@@ -0,0 +1,33 @@
+package data
+
+import "io"
+
+type Store interface {
+    Open(string) (io.ReadWriteCloser, error)
+}
+
+
+type StorageType int
+
+const (
+    DiskStorage StorageType = 1 << iota
+    TempStorage
+    MemoryStorage
+)
+
+func NewStore(t StorageType) Store {
+    switch t {
+    case MemoryStorage:
+        return newMemoryStorage( /*...*/ )
+    case DiskStorage:
+        return newDiskStorage( /*...*/ )
+    default:
+        return newTempStorage( /*...*/ )
+    }
+}
+
+s, _ := NewStore(data.MemoryStorage)
+f, _ := s.Open("file")
+
+n, _ := f.Write([]byte("data"))
+defer f.Close()