walk: deal with maps

walk/walk.go

@@ -19,6 +19,10 @@ func Walk(x interface{}, fn func(string)) {
 	case reflect.Slice, reflect.Array:
 		numberOfValues = val.Len()
 		getField = val.Index
+	case reflect.Map:
+		for _, key := range val.MapKeys() {
+			Walk(val.MapIndex(key).Interface(), fn)
+		}
 	}
 
 	for i := 0; i < numberOfValues; i++ {

walk/walk_test.go

@@ -70,6 +70,14 @@ func TestWalk(t *testing.T) {
 			},
 			[]string{"London", "Paris"},
 		},
+		{
+			"maps",
+			map[string]string{
+				"Cow":   "meuh",
+				"Sheep": "meh",
+			},
+			[]string{"meuh", "meh"},
+		},
 	}
 
 	for _, test := range cases {