use functional options handle copy option (#5)

egoist · May 7, 2020 · be85817 · be85817
1 parent bf3a121
commit be85817
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Showing 2 changed files with 14 additions and 14 deletions.
diff --git a/utils/copy.go b/utils/copy.go
@@ -15,7 +15,7 @@ const (
 )
 
 // Copy copies src to dest, doesn't matter if src is a directory or a file.
-func Copy(src, dest string, opt ...Options) error {
+func Copy(src, dest string, opt ...CopyOption) error {
 	info, err := os.Lstat(src)
 	if err != nil {
 		return err
@@ -26,7 +26,7 @@ func Copy(src, dest string, opt ...Options) error {
 // copy dispatches copy-funcs according to the mode.
 // Because this "copy" could be called recursively,
 // "info" MUST be given here, NOT nil.
-func copy(src, dest string, info os.FileInfo, opt Options) error {
+func copy(src, dest string, info os.FileInfo, opt *Options) error {
 
 	if opt.Skip(src) {
 		return nil
@@ -45,7 +45,7 @@ func copy(src, dest string, info os.FileInfo, opt Options) error {
 // fcopy is for just a file,
 // with considering existence of parent directory
 // and file permission.
-func fcopy(src, dest string, info os.FileInfo, opt Options) (err error) {
+func fcopy(src, dest string, info os.FileInfo, opt *Options) (err error) {
 
 	if err = os.MkdirAll(filepath.Dir(dest), os.ModePerm); err != nil {
 		return
@@ -81,7 +81,7 @@ func fcopy(src, dest string, info os.FileInfo, opt Options) (err error) {
 // dcopy is for a directory,
 // with scanning contents inside the directory
 // and pass everything to "copy" recursively.
-func dcopy(srcdir, destdir string, info os.FileInfo, opt Options) (err error) {
+func dcopy(srcdir, destdir string, info os.FileInfo, opt *Options) (err error) {
 
 	originalMode := info.Mode()
 
@@ -108,7 +108,7 @@ func dcopy(srcdir, destdir string, info os.FileInfo, opt Options) (err error) {
 	return
 }
 
-func onsymlink(src, dest string, info os.FileInfo, opt Options) error {
+func onsymlink(src, dest string, info os.FileInfo, opt *Options) error {
 
 	switch opt.OnSymlink(src) {
 	case Shallow:
@@ -160,16 +160,13 @@ func chmod(dir string, mode os.FileMode, reported *error) {
 
 // assure Options struct, should be called only once.
 // All optional values MUST NOT BE nil/zero after assured.
-func assure(opts ...Options) Options {
+func assure(opts ...CopyOption) *Options {
 	if len(opts) == 0 {
 		return getDefaultOptions()
 	}
 	defopt := getDefaultOptions()
-	if opts[0].OnSymlink == nil {
-		opts[0].OnSymlink = defopt.OnSymlink
+	for _, opt := range opts {
+		opt(defopt)
 	}
-	if opts[0].Skip == nil {
-		opts[0].Skip = defopt.Skip
-	}
-	return opts[0]
+	return defopt
 }
diff --git a/utils/copy_options.go b/utils/copy_options.go
@@ -30,10 +30,13 @@ const (
 	Skip
 )
 
+// CopyOption define a function type that handle optional actions.
+type CopyOption func(*Options)
+
 // getDefaultOptions provides default options,
 // which would be modified by usage-side.
-func getDefaultOptions() Options {
-	return Options{
+func getDefaultOptions() *Options {
+	return &Options{
 		OnSymlink: func(string) SymlinkAction {
 			return Shallow // Do shallow copy
 		},