???

file_util.go

@@ -14,24 +14,30 @@ var (
 type fileUtil struct{}
 
 // ReadByLines reads a file and calls the handler for each line.
-func (fu fileUtil) ReadByLines(filePath string, handler func(line string)) error {
-	if f, err := os.Open(filePath); err == nil {
+func (fu fileUtil) ReadByLines(filePath string, handler func(line string) error) error {
+	var f *os.File
+	var err error
+	if f, err = os.Open(filePath); err == nil {
 		defer f.Close()
-
+		var line string
 		scanner := bufio.NewScanner(f)
 		for scanner.Scan() {
-			line := scanner.Text()
-			handler(line)
-		}
-	} else {
+			line = scanner.Text()
+			err = handler(line)
+			if err != nil {
 				return err
 			}
-	return nil
+		}
+	}
+	return err
+
 }
 
 // ReadByChunks reads a file in `chunkSize` pieces, dispatched to the handler.
-func (fu fileUtil) ReadByChunks(filePath string, chunkSize int, handler func(line []byte)) error {
-	if f, err := os.Open(filePath); err == nil {
+func (fu fileUtil) ReadByChunks(filePath string, chunkSize int, handler func(line []byte) error) error {
+	var f *os.File
+	var err error
+	if f, err = os.Open(filePath); err == nil {
 		defer f.Close()
 
 		chunk := make([]byte, chunkSize)
@@ -41,10 +47,11 @@ func (fu fileUtil) ReadByChunks(filePath string, chunkSize int, handler func(lin
 				break
 			}
 			readData := chunk[:readBytes]
-			handler(readData)
-		}
-	} else {
+			err = handler(readData)
+			if err != nil {
 				return err
 			}
-	return nil
+		}
+	}
+	return err
 }

value_formatter.go

@@ -10,21 +10,33 @@ type ValueFormatter func(v interface{}) string
 
 // TimeValueFormatter is a ValueFormatter for timestamps.
 func TimeValueFormatter(v interface{}) string {
-	return TimeValueFormatterWithFormat(v, DefaultDateFormat)
+	return formatTime(v, DefaultDateFormat)
 }
 
 // TimeHourValueFormatter is a ValueFormatter for timestamps.
 func TimeHourValueFormatter(v interface{}) string {
-	return TimeValueFormatterWithFormat(v, DefaultDateHourFormat)
+	return formatTime(v, DefaultDateHourFormat)
 }
 
 // TimeMinuteValueFormatter is a ValueFormatter for timestamps.
 func TimeMinuteValueFormatter(v interface{}) string {
-	return TimeValueFormatterWithFormat(v, DefaultDateMinuteFormat)
+	return formatTime(v, DefaultDateMinuteFormat)
+}
+
+// TimeDateValueFormatter is a ValueFormatter for timestamps.
+func TimeDateValueFormatter(v interface{}) string {
+	return formatTime(v, "2006-01-02")
+}
+
+// TimeValueFormatterWithFormat returns a time formatter with a given format.
+func TimeValueFormatterWithFormat(format string) ValueFormatter {
+	return func(v interface{}) string {
+		return formatTime(v, format)
+	}
 }
 
 // TimeValueFormatterWithFormat is a ValueFormatter for timestamps with a given format.
-func TimeValueFormatterWithFormat(v interface{}, dateFormat string) string {
+func formatTime(v interface{}, dateFormat string) string {
 	if typed, isTyped := v.(time.Time); isTyped {
 		return typed.Format(dateFormat)
 	}