bytes: add Buffer.UnreadRune, Buffer.UnreadByte
R=rsc, r
CC=golang-dev
https://golang.org/cl/3421041
diff --git a/src/pkg/bytes/buffer_test.go b/src/pkg/bytes/buffer_test.go
index a95068a..2801ad1 100644
--- a/src/pkg/bytes/buffer_test.go
+++ b/src/pkg/bytes/buffer_test.go
@@ -275,10 +275,10 @@
size := utf8.EncodeRune(b[n:], r)
nbytes, err := buf.WriteRune(r)
if err != nil {
- t.Fatalf("WriteRune(0x%x) error: %s", r, err)
+ t.Fatalf("WriteRune(U+%.4x) error: %s", r, err)
}
if nbytes != size {
- t.Fatalf("WriteRune(0x%x) expected %d, got %d", r, size, nbytes)
+ t.Fatalf("WriteRune(U+%.4x) expected %d, got %d", r, size, nbytes)
}
n += size
}
@@ -289,12 +289,27 @@
t.Fatalf("incorrect result from WriteRune: %q not %q", buf.Bytes(), b)
}
+ p := make([]byte, utf8.UTFMax)
// Read it back with ReadRune
for r := 0; r < NRune; r++ {
- size := utf8.EncodeRune(b, r)
+ size := utf8.EncodeRune(p, r)
nr, nbytes, err := buf.ReadRune()
if nr != r || 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)
+ t.Fatalf("ReadRune(U+%.4x) got U+%.4x,%d not U+%.4x,%d (err=%s)", r, nr, nbytes, r, size, err)
+ }
+ }
+
+ // Check that UnreadRune works
+ buf.Reset()
+ buf.Write(b)
+ for r := 0; r < NRune; r++ {
+ r1, size, _ := buf.ReadRune()
+ if err := buf.UnreadRune(); err != nil {
+ t.Fatalf("UnreadRune(U+%.4x) got error %q", r, err)
+ }
+ r2, nbytes, err := buf.ReadRune()
+ if r1 != r2 || r1 != r || nbytes != size || err != nil {
+ t.Fatalf("ReadRune(U+%.4x) after UnreadRune got U+%.4x,%d not U+%.4x,%d (err=%s)", r, r2, nbytes, r, size, err)
}
}
}
