Add handling for + char in metric names

Author: carrieedwards

pkg/parser/parser.go

@@ -570,7 +570,7 @@ func IsNameChar(r byte) bool {
 		r == '<' || r == '>' ||
 		r == '&' || r == '#' ||
 		r == '/' || r == '%' ||
-		r == '@'
+		r == '@' || r == '+'
 }
 
 func isDigit(r byte) bool {

pkg/parser/parser_test.go

@@ -264,6 +264,13 @@ func TestParseExpr(t *testing.T) {
 				etype:  EtName,
 			},
 		},
+		{
+			`foo.b[0-9]+.qux`,
+			&expr{
+				target: "foo.b[0-9]+.qux",
+				etype:  EtName,
+			},
+		},
 		{
 			`virt.v1.*.text-match:<foo.bar.qux>`,
 			&expr{