Add generate.go

element.go

@@ -1,7 +1,10 @@
 package gcss
 
+import "io"
+
 // element represents an element of GCSS source codes.
 type element interface {
+	io.WriterTo
 	AppendChild(child element)
 	Base() *elementBase
 }

generate.go

@@ -0,0 +1,11 @@
+package gcss
+
+func generate(elems []element) (<-chan string, <-chan error) {
+	sc := make(chan string)
+	errc := make(chan error)
+
+	go func() {
+		sc <- ""
+	}()
+	return sc, errc
+}

generate_test.go

@@ -0,0 +1,11 @@
+package gcss
+
+import "testing"
+
+func Test_generate(t *testing.T) {
+	sc, errc := generate(nil)
+	select {
+	case <-sc:
+	case <-errc:
+	}
+}

parse.go

@@ -18,7 +18,7 @@ func parse(s string) (<-chan []element, <-chan error) {
 	errc := make(chan error)
 
 	go func() {
-		var elements []element
+		var elems []element
 
 		lines := strings.Split(formatLF(s), lf)
 
@@ -43,11 +43,11 @@ func parse(s string) (<-chan []element, <-chan error) {
 					return
 				}
 
-				elements = append(elements, e)
+				elems = append(elems, e)
 			}
 		}
 
-		elemsc <- elements
+		elemsc <- elems
 	}()
 
 	return elemsc, errc

selector.go

@@ -1,10 +1,16 @@
 package gcss
 
+import "io"
+
 // selector represents a selector.
 type selector struct {
 	elementBase
 }
 
+func (sel *selector) WriteTo(w io.Writer) (n int64, err error) {
+	return 0, nil
+}
+
 // newSelector creates and returns a selector.
 func newSelector(ln *line, parent element) *selector {
 	return &selector{

selector_test.go

@@ -1,6 +1,21 @@
 package gcss
 
-import "testing"
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func Test_selector_WriteTo(t *testing.T) {
+	ln := newLine(1, "html")
+
+	sel := newSelector(ln, nil)
+
+	_, err := sel.WriteTo(ioutil.Discard)
+
+	if err != nil {
+		t.Errorf("err should be nil [err: %s]", err.Error())
+	}
+}
 
 func Test_newSelector(t *testing.T) {
 	ln := newLine(1, "html")