diff --git a/editor/editors.go b/editor/editors.go
index ca361b5..dd51eae 100644
--- a/editor/editors.go
+++ b/editor/editors.go
@@ -384,7 +384,7 @@ func FindUsagesHandler(w http.ResponseWriter, r *http.Request) {
 	offset := getCursorOffset(code, line, ch)
 	// glog.Infof("offset [%d]", offset)
 
-	idestub := util.Go.GetExecutableInGOBIN("ide_stub")
+	ideStub := util.Go.GetExecutableInGOBIN("ide_stub")
 	argv := []string{"type", "-cursor", filename + ":" + strconv.Itoa(offset), "-use", "."}
 	cmd := exec.Command(ideStub, argv...)
 	cmd.Dir = curDir
diff --git a/event/events.go b/event/events.go
index eae2d40..74a0878 100644
--- a/event/events.go
+++ b/event/events.go
@@ -127,10 +127,10 @@ type Handler interface {
 	Handle(event *Event)
 }
 
-// Type of handler function.
-type handleFunc func(event *Event)
+// HandleFunc represents a handler function.
+type HandleFunc func(event *Event)
 
 // Default implementation of event handling.
-func (fn handleFunc) Handle(event *Event) {
+func (fn HandleFunc) Handle(event *Event) {
 	fn(event)
 }
diff --git a/file/files.go b/file/files.go
index d0a7823..a847405 100644
--- a/file/files.go
+++ b/file/files.go
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-// File tree manipulations.
+// Package file includes file related manipulations.
 package file
 
 import (
@@ -31,19 +31,19 @@ import (
 	"github.com/golang/glog"
 )
 
-// File node, used to construct the file tree.
-type FileNode struct {
-	Name      string      `json:"name"`
-	Path      string      `json:"path"`
-	IconSkin  string      `json:"iconSkin"`  // Value should be end with a space
-	Type      string      `json:"type"`      // "f": file, "d": directory
-	Creatable bool        `json:"creatable"` // whether can create file in this file node
-	Removable bool        `json:"removable"` // whether can remove this file node
-	Mode      string      `json:"mode"`
-	FileNodes []*FileNode `json:"children"`
+// Node represents a file node in file tree.
+type Node struct {
+	Name      string  `json:"name"`
+	Path      string  `json:"path"`
+	IconSkin  string  `json:"iconSkin"`  // Value should be end with a space
+	Type      string  `json:"type"`      // "f": file, "d": directory
+	Creatable bool    `json:"creatable"` // whether can create file in this file node
+	Removable bool    `json:"removable"` // whether can remove this file node
+	Mode      string  `json:"mode"`
+	Children  []*Node `json:"children"`
 }
 
-// Source code snippet, used to as the result of "Find Usages", "Search".
+// Snippet represents a source code snippet, used to as the result of "Find Usages", "Search".
 type Snippet struct {
 	Path     string   `json:"path"`     // file path
 	Line     int      `json:"line"`     // line number
@@ -51,14 +51,14 @@ type Snippet struct {
 	Contents []string `json:"contents"` // lines nearby
 }
 
-var apiNode *FileNode
+var apiNode *Node
 
 // initAPINode builds the Go API file node.
 func initAPINode() {
 	apiPath := util.Go.GetAPIPath()
 
-	apiNode = &FileNode{Name: "Go API", Path: apiPath, IconSkin: "ico-ztree-dir-api ", Type: "d",
-		Creatable: false, Removable: false, FileNodes: []*FileNode{}}
+	apiNode = &Node{Name: "Go API", Path: apiPath, IconSkin: "ico-ztree-dir-api ", Type: "d",
+		Creatable: false, Removable: false, Children: []*Node{}}
 
 	walk(apiPath, apiNode, false, false)
 }
@@ -82,7 +82,7 @@ func GetFiles(w http.ResponseWriter, r *http.Request) {
 	userWorkspace := conf.Wide.GetUserWorkspace(username)
 	workspaces := filepath.SplitList(userWorkspace)
 
-	root := FileNode{Name: "root", Path: "", IconSkin: "ico-ztree-dir ", Type: "d", FileNodes: []*FileNode{}}
+	root := Node{Name: "root", Path: "", IconSkin: "ico-ztree-dir ", Type: "d", Children: []*Node{}}
 
 	if nil == apiNode { // lazy init
 		initAPINode()
@@ -92,18 +92,18 @@ func GetFiles(w http.ResponseWriter, r *http.Request) {
 	for _, workspace := range workspaces {
 		workspacePath := workspace + conf.PathSeparator + "src"
 
-		workspaceNode := FileNode{Name: workspace[strings.LastIndex(workspace, conf.PathSeparator)+1:],
+		workspaceNode := Node{Name: workspace[strings.LastIndex(workspace, conf.PathSeparator)+1:],
 			Path: workspacePath, IconSkin: "ico-ztree-dir-workspace ", Type: "d",
-			Creatable: true, Removable: false, FileNodes: []*FileNode{}}
+			Creatable: true, Removable: false, Children: []*Node{}}
 
 		walk(workspacePath, &workspaceNode, true, true)
 
 		// add workspace node
-		root.FileNodes = append(root.FileNodes, &workspaceNode)
+		root.Children = append(root.Children, &workspaceNode)
 	}
 
 	// add Go API node
-	root.FileNodes = append(root.FileNodes, apiNode)
+	root.Children = append(root.Children, apiNode)
 
 	data["root"] = root
 }
@@ -113,12 +113,12 @@ func RefreshDirectory(w http.ResponseWriter, r *http.Request) {
 	r.ParseForm()
 	path := r.FormValue("path")
 
-	node := FileNode{Name: "root", Path: path, IconSkin: "ico-ztree-dir ", Type: "d", FileNodes: []*FileNode{}}
+	node := Node{Name: "root", Path: path, IconSkin: "ico-ztree-dir ", Type: "d", Children: []*Node{}}
 
 	walk(path, &node, true, true)
 
 	w.Header().Set("Content-Type", "application/json")
-	data, err := json.Marshal(node.FileNodes)
+	data, err := json.Marshal(node.Children)
 	if err != nil {
 		glog.Error(err)
 		return
@@ -417,7 +417,7 @@ func SearchText(w http.ResponseWriter, r *http.Request) {
 }
 
 // walk traverses the specified path to build a file tree.
-func walk(path string, node *FileNode, creatable, removable bool) {
+func walk(path string, node *Node, creatable, removable bool) {
 	files := listFiles(path)
 
 	for _, filename := range files {
@@ -425,8 +425,8 @@ func walk(path string, node *FileNode, creatable, removable bool) {
 
 		fio, _ := os.Lstat(fpath)
 
-		child := FileNode{Name: filename, Path: fpath, Removable: removable, FileNodes: []*FileNode{}}
-		node.FileNodes = append(node.FileNodes, &child)
+		child := Node{Name: filename, Path: fpath, Removable: removable, Children: []*Node{}}
+		node.Children = append(node.Children, &child)
 
 		if nil == fio {
 			glog.Warningf("Path [%s] is nil", fpath)
diff --git a/file/importer.go b/file/importer.go
index 3db30d9..5a470ac 100644
--- a/file/importer.go
+++ b/file/importer.go
@@ -10,14 +10,14 @@ import (
 	"github.com/b3log/wide/util"
 )
 
-type FileInfo struct {
+type fileInfo struct {
 	Name  string `json:"name"`
 	Type  string `json:"type"`
 	Error string `json:"error,omitempty"`
 }
 
-func handleUpload(p *multipart.Part, dir string) (fi *FileInfo) {
-	fi = &FileInfo{
+func handleUpload(p *multipart.Part, dir string) (fi *fileInfo) {
+	fi = &fileInfo{
 		Name: p.FileName(),
 		Type: p.Header.Get("Content-Type"),
 	}
@@ -32,8 +32,8 @@ func handleUpload(p *multipart.Part, dir string) (fi *FileInfo) {
 	return
 }
 
-func handleUploads(r *http.Request, dir string) (fileInfos []*FileInfo) {
-	fileInfos = make([]*FileInfo, 0)
+func handleUploads(r *http.Request, dir string) (fileInfos []*fileInfo) {
+	fileInfos = make([]*fileInfo, 0)
 	mr, err := r.MultipartReader()
 
 	part, err := mr.NextPart()