json.h: avoid expanding `o` twiceHEADmain

Signed-off-by: Anna (navi) Figueiredo Gomes <navi@vlhl.dev>

1 files changed, 8 insertions, 3 deletions

diff --git a/include/json.h b/include/json.h
index 85749d6..c8c844e 100644
--- a/include/json.h
+++ b/include/json.h
@@ -129,9 +129,6 @@ struct json *json_bool(bool boolean);
 
 char *json_print(struct json *json);
 
-#define json_foreach(e, o) \
-	for (struct json *e = json_check_type((o), JSON_OBJECT | JSON_ARRAY) ? (o)->children->items[0] : NULL; e; e = e->next)
-
 static inline bool json_check_type(const struct json *json, const enum json_type type) {
 	return json && json->type & type;
 }
@@ -160,4 +157,12 @@ static inline bool json_is_null(const struct json *json) {
 	return json && json->type == JSON_NULL;
 }
 
+#define json_foreach(e, o) \
+	for (struct json *e = json_iter((o)); e; e = e->next)
+
+// Avoid expanding `o` twice in the foreach macro
+static inline struct json *json_iter(struct json *json) {
+	return json_check_type(json, JSON_OBJECT | JSON_ARRAY) ? json->children->items[0] : NULL;
+}
+
 #endif