move kv to label

output/label/kv.go

@@ -0,0 +1,63 @@
+package label
+
+import (
+	"fmt"
+	"strings"
+)
+
+var (
+	_ fmt.Stringer = KeyValue{}
+	_ fmt.Stringer = KeyValues{}
+)
+
+type KeyValues []KeyValue
+
+func (kv KeyValues) String() string {
+	s := make([]string, len(kv))
+	for i, v := range kv {
+		s[i] = v.String()
+	}
+
+	return strings.Join(s, ", ")
+}
+
+type KeyValue struct {
+	Key   Key
+	Value Value
+}
+
+func (k KeyValue) String() string {
+	return string(k.Key) + "=\"" + k.Value.String() + "\""
+}
+
+func Any(k string, v interface{}) KeyValue {
+	return Key(k).Any(v)
+}
+
+func Bool(k string, v bool) KeyValue {
+	return Key(k).Bool(v)
+}
+
+func Int(k string, v int) KeyValue {
+	return Key(k).Int(v)
+}
+
+func Int64(k string, v int64) KeyValue {
+	return Key(k).Int64(v)
+}
+
+func Uint(k string, v uint) KeyValue {
+	return Key(k).Uint(v)
+}
+
+func Uint64(k string, v uint64) KeyValue {
+	return Key(k).Uint64(v)
+}
+
+func Float64(k string, v float64) KeyValue {
+	return Key(k).Float64(v)
+}
+
+func String(k string, v string) KeyValue {
+	return Key(k).String(v)
+}