promql: add MarshalJSON method for ExprType.

10 years ago · 7f85b9b215
parent 52859b8033
commit 7f85b9b215
1 changed files with 6 additions and 0 deletions
--- a/promql/ast.go
+++ b/promql/ast.go
@ -14,6 +14,7 @@
 package promql

 import (
+	"encoding/json"
 	"fmt"
 	"time"

@ -97,6 +98,11 @@ const (
 	ExprString
 )

+// MarshalJSON implements json.Marshaler.
+func (et ExprType) MarshalJSON() ([]byte, error) {
+	return json.Marshal(et.String())
+}
+
 func (e ExprType) String() string {
 	switch e {
 	case ExprNone: