WriteString

R=rsc
DELTA=41  (41 added, 0 deleted, 0 changed)
OCL=32692
CL=32697

src/pkg/bufio/bufio.go

@@ -487,6 +487,25 @@ func (b *Writer) WriteByte(c byte) os.Error {
 	return nil
 }
 
+// WriteString writes a string.
+func (b *Writer) WriteString(s string) os.Error {
+	if b.err != nil {
+		return b.err
+	}
+	// Common case, worth making fast.
+	if b.Available() >= len(s) || len(b.buf) >= len(s) && b.Flush() == nil {
+		for i := 0; i < len(s); i++ {	// loop over bytes, not runes.
+			b.buf[b.n] = s[i];
+			b.n++;
+		}
+		return nil;
+	}
+	for i := 0; i < len(s); i++ {	// loop over bytes, not runes.
+		b.WriteByte(s[i]);
+	}
+	return b.err
+}
+
 // buffered input and output
 
 // ReadWriter stores pointers to a Reader and a Writer.

src/pkg/bufio/bufio_test.go

@@ -298,3 +298,25 @@ func TestNewWriterSizeIdempotent(t *testing.T) {
 		t.Error("NewWriterSize did not enlarge buffer");
 	}
 }
+
+func TestWriteString(t *testing.T) {
+	const BufSize = 8;
+	buf := new(bytes.Buffer);
+	b, err := NewWriterSize(buf, BufSize);
+	if err != nil {
+		t.Error("NewWriterSize create fail", err);
+	}
+	b.WriteString("0");	// easy
+	b.WriteString("123456");	// still easy
+	b.WriteString("7890");	// easy after flush
+	b.WriteString("abcdefghijklmnopqrstuvwxy");	// hard
+	b.WriteString("z");
+	b.Flush();
+	if b.err != nil {
+		t.Error("WriteString", b.err);
+	}
+	s := "01234567890abcdefghijklmnopqrstuvwxyz";
+	if string(buf.Data()) != s {
+		t.Errorf("WriteString wants %q gets %q", s, string(buf.Data()))
+	}
+}