1 files changed, 20 insertions, 0 deletions
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 29664aa6e40..a24d498b060 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -5528,3 +5528,23 @@ transform_string_values_scalar(void *state, char *token, JsonTokenType tokentype
 	else
 		appendStringInfoString(_state->strval, token);
 }
+
+JsonTokenType
+json_get_first_token(text *json, bool throw_error)
+{
+	JsonLexContext *lex;
+	JsonParseErrorType result;
+
+	lex = makeJsonLexContext(json, false);
+
+	/* Lex exactly one token from the input and check its type. */
+	result = json_lex(lex);
+
+	if (result == JSON_SUCCESS)
+		return lex->token_type;
+
+	if (throw_error)
+		json_ereport_error(result, lex);
+
+	return JSON_TOKEN_INVALID;	/* invalid json */
+}