nvim: add documentation to bufferReader.Read and use named return

Author: zchee

nvim/helpers.go

@@ -70,6 +70,9 @@ type bufferReader struct {
 err error
 }
 
+// compile time check whether the bufferReader implements io.Reader interface.
+var _ io.Reader = (*bufferReader)(nil)
+
 // NewBufferReader returns a reader for the specified buffer. If b = 0, then
 // the current buffer is used.
 func NewBufferReader(v *Nvim, b Buffer) io.Reader {
@@ -78,7 +81,8 @@ func NewBufferReader(v *Nvim, b Buffer) io.Reader {
 
 var lineEnd = []byte{'\n'}
 
-func (r *bufferReader) Read(p []byte) (int, error) {
+// Read implements io.Reader.
+func (r *bufferReader) Read(p []byte) (n int, err error) {
 if r.err != nil {
 return 0, r.err
 }
@@ -88,7 +92,6 @@ func (r *bufferReader) Read(p []byte) (int, error) {
 return 0, r.err
 }
 }
-n := 0
 for {
 if len(r.lines) == 0 {
 r.err = io.EOF
@@ -97,6 +100,7 @@ func (r *bufferReader) Read(p []byte) (int, error) {
 if len(p) == 0 {
 return n, nil
 }
+
 line0 := r.lines[0]
 if len(line0) == 0 {
 p[0] = '\n'
@@ -105,6 +109,7 @@ func (r *bufferReader) Read(p []byte) (int, error) {
 r.lines = r.lines[1:]
 continue
 }
+
 nn := copy(p, line0)
 n += nn
 p = p[nn:]