1 files changed, 33 insertions, 0 deletions
diff --git a/go/src/lib/statusline/statusline.go b/go/src/lib/statusline/statusline.go
new file mode 100644
index 0000000..bedf952
--- /dev/null
+++ b/go/src/lib/statusline/statusline.go
@@ -0,0 +1,33 @@
+package statusline
+
+import (
+	"fmt"
+	"io"
+)
+
+type StatusLine interface {
+	Put(line string)
+	End(keep bool)
+}
+
+type statusLine struct {
+	out     io.Writer
+	prevLen int
+}
+
+func New(out io.Writer) StatusLine {
+	return &statusLine{out: out}
+}
+
+func (sl *statusLine) Put(line string) {
+	fmt.Fprintf(sl.out, "\r%-[1]*[2]s", sl.prevLen, line)
+	sl.prevLen = len(line)
+}
+
+func (sl *statusLine) End(keep bool) {
+	if keep {
+		io.WriteString(sl.out, "\n")
+	} else {
+		fmt.Fprintf(sl.out, "\r%-[1]*[2]s\r", sl.prevLen, "")
+	}
+}