bufio, io: use rune

ReadRune, WriteRune change signature.

R=golang-dev, gri, r
CC=golang-dev
https://golang.org/cl/5314043

src/pkg/bufio/bufio.go

@@ -208,7 +208,7 @@ func (b *Reader) UnreadByte() os.Error {
 
 // ReadRune reads a single UTF-8 encoded Unicode character and returns the
 // rune and its size in bytes.
-func (b *Reader) ReadRune() (rune int, size int, err os.Error) {
+func (b *Reader) ReadRune() (r rune, size int, err os.Error) {
 	for b.r+utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) && b.err == nil {
 		b.fill()
 	}
@@ -216,14 +216,14 @@ func (b *Reader) ReadRune() (rune int, size int, err os.Error) {
 	if b.r == b.w {
 		return 0, 0, b.readErr()
 	}
-	rune, size = int(b.buf[b.r]), 1
-	if rune >= 0x80 {
-		rune, size = utf8.DecodeRune(b.buf[b.r:b.w])
+	r, size = rune(b.buf[b.r]), 1
+	if r >= 0x80 {
+		r, size = utf8.DecodeRune(b.buf[b.r:b.w])
 	}
 	b.r += size
 	b.lastByte = int(b.buf[b.r-1])
 	b.lastRuneSize = size
-	return rune, size, nil
+	return r, size, nil
 }
 
 // UnreadRune unreads the last rune.  If the most recent read operation on
@@ -497,9 +497,9 @@ func (b *Writer) WriteByte(c byte) os.Error {
 
 // WriteRune writes a single Unicode code point, returning
 // the number of bytes written and any error.
-func (b *Writer) WriteRune(rune int) (size int, err os.Error) {
-	if rune < utf8.RuneSelf {
-		err = b.WriteByte(byte(rune))
+func (b *Writer) WriteRune(r rune) (size int, err os.Error) {
+	if r < utf8.RuneSelf {
+		err = b.WriteByte(byte(r))
 		if err != nil {
 			return 0, err
 		}
@@ -516,10 +516,10 @@ func (b *Writer) WriteRune(rune int) (size int, err os.Error) {
 		n = b.Available()
 		if n < utf8.UTFMax {
 			// Can only happen if buffer is silly small.
-			return b.WriteString(string(rune))
+			return b.WriteString(string(r))
 		}
 	}
-	size = utf8.EncodeRune(b.buf[b.n:], rune)
+	size = utf8.EncodeRune(b.buf[b.n:], r)
 	b.n += size
 	return size, nil
 }

src/pkg/bufio/bufio_test.go

@@ -195,14 +195,14 @@ func readRuneSegments(t *testing.T, segments []string) {
 	want := strings.Join(segments, "")
 	r := NewReader(&StringReader{data: segments})
 	for {
-		rune, _, err := r.ReadRune()
+		r, _, err := r.ReadRune()
 		if err != nil {
 			if err != os.EOF {
 				return
 			}
 			break
 		}
-		got += string(rune)
+		got += string(r)
 	}
 	if got != want {
 		t.Errorf("segments=%v got=%s want=%s", segments, got, want)
@@ -233,24 +233,24 @@ func TestUnreadRune(t *testing.T) {
 	r := NewReader(&StringReader{data: segments})
 	// Normal execution.
 	for {
-		rune, _, err := r.ReadRune()
+		r1, _, err := r.ReadRune()
 		if err != nil {
 			if err != os.EOF {
 				t.Error("unexpected EOF")
 			}
 			break
 		}
-		got += string(rune)
+		got += string(r1)
 		// Put it back and read it again
 		if err = r.UnreadRune(); err != nil {
 			t.Error("unexpected error on UnreadRune:", err)
 		}
-		rune1, _, err := r.ReadRune()
+		r2, _, err := r.ReadRune()
 		if err != nil {
 			t.Error("unexpected error reading after unreading:", err)
 		}
-		if rune != rune1 {
-			t.Errorf("incorrect rune after unread: got %c wanted %c", rune1, rune)
+		if r1 != r2 {
+			t.Errorf("incorrect rune after unread: got %c wanted %c", r1, r2)
 		}
 	}
 	if got != data {
@@ -339,25 +339,25 @@ func TestReadWriteRune(t *testing.T) {
 	w := NewWriter(byteBuf)
 	// Write the runes out using WriteRune
 	buf := make([]byte, utf8.UTFMax)
-	for rune := 0; rune < NRune; rune++ {
-		size := utf8.EncodeRune(buf, rune)
-		nbytes, err := w.WriteRune(rune)
+	for r := rune(0); r < NRune; r++ {
+		size := utf8.EncodeRune(buf, r)
+		nbytes, err := w.WriteRune(r)
 		if err != nil {
-			t.Fatalf("WriteRune(0x%x) error: %s", rune, err)
+			t.Fatalf("WriteRune(0x%x) error: %s", r, err)
 		}
 		if nbytes != size {
-			t.Fatalf("WriteRune(0x%x) expected %d, got %d", rune, size, nbytes)
+			t.Fatalf("WriteRune(0x%x) expected %d, got %d", r, size, nbytes)
 		}
 	}
 	w.Flush()
 
 	r := NewReader(byteBuf)
 	// Read them back with ReadRune
-	for rune := 0; rune < NRune; rune++ {
-		size := utf8.EncodeRune(buf, rune)
+	for r1 := rune(0); r1 < NRune; r1++ {
+		size := utf8.EncodeRune(buf, r1)
 		nr, nbytes, err := r.ReadRune()
-		if nr != rune || nbytes != size || err != nil {
-			t.Fatalf("ReadRune(0x%x) got 0x%x,%d not 0x%x,%d (err=%s)", r, nr, nbytes, r, size, err)
+		if nr != r1 || nbytes != size || err != nil {
+			t.Fatalf("ReadRune(0x%x) got 0x%x,%d not 0x%x,%d (err=%s)", r1, nr, nbytes, r1, size, err)
 		}
 	}
 }

src/pkg/io/io.go

@@ -194,7 +194,7 @@ type ByteScanner interface {
 // and returns the rune and its size in bytes. If no character is
 // available, err will be set.
 type RuneReader interface {
-	ReadRune() (rune int, size int, err os.Error)
+	ReadRune() (r rune, size int, err os.Error)
 }
 
 // RuneScanner is the interface that adds the UnreadRune method to the