Abstracts away statement printing

main.go

@@ -183,14 +183,15 @@ func gron(r io.Reader, w io.Writer, opts int) (int, error) {
 		sort.Sort(ss)
 	}
 
+	var conv statementconv
 	if opts&optMonochrome > 0 {
-		for _, s := range ss {
-			fmt.Fprintln(w, s.String())
-		}
+		conv = statementToString
 	} else {
-		for _, s := range ss {
-			fmt.Fprintln(w, s.colorString())
-		}
+		conv = statementToColorString
+	}
+
+	for _, s := range ss {
+		fmt.Fprintln(w, conv(s))
 	}
 
 	return exitOK, nil
@@ -219,12 +220,16 @@ func gronStream(r io.Reader, w io.Writer, opts int) (int, error) {
 		{"[]", typEmptyArray},
 		{";", typSemi},
 	}
+
+	var conv func(s statement) string
 	if opts&optMonochrome > 0 {
-		fmt.Fprintln(w, top.String())
+		conv = statementToString
 	} else {
-		fmt.Fprintln(w, top.colorString())
+		conv = statementToColorString
 	}
 
+	fmt.Fprintln(w, conv(top))
+
 	// Read the input line by line
 	sc := bufio.NewScanner(r)
 	buf := make([]byte, 0, 64*1024)
@@ -246,14 +251,8 @@ func gronStream(r io.Reader, w io.Writer, opts int) (int, error) {
 			sort.Sort(ss)
 		}
 
-		if opts&optMonochrome > 0 {
-			for _, s := range ss {
-				fmt.Fprintln(w, s.String())
-			}
-		} else {
-			for _, s := range ss {
-				fmt.Fprintln(w, s.colorString())
-			}
+		for _, s := range ss {
+			fmt.Fprintln(w, conv(s))
 		}
 	}
 	if err := sc.Err(); err != nil {

statements.go

@@ -40,6 +40,19 @@ func (s statement) colorString() string {
 	return strings.Join(out, "")
 }
 
+// a statementconv converts a statement to string
+type statementconv func(s statement) string
+
+// statementconv variant of statement.String
+func statementToString(s statement) string {
+	return s.String()
+}
+
+// statementconv variant of statement.colorString
+func statementToColorString(s statement) string {
+	return s.colorString()
+}
+
 // withBare returns a copy of a statement with a new bare
 // word token appended to it
 func (s statement) withBare(k string) statement {