Function op_signature_string

src/backend/parser/parse_oper.c:613–628

* op_signature_string * Build a string representing an operator name, including arg type(s). * The result is something like "integer + integer". * * This is typically used in the construction of operator-not-found error * messages. */

 * messages.
 */
static const char *
op_signature_string(List *op, char oprkind, Oid arg1, Oid arg2)
{
	StringInfoData argbuf;

	initStringInfo(&argbuf);

	if (oprkind != 'l')
		appendStringInfo(&argbuf, "%s ", format_type_be(arg1));

	appendStringInfoString(&argbuf, NameListToString(op));

	appendStringInfo(&argbuf, " %s", format_type_be(arg2));

	return argbuf.data;			/* return palloc'd string buffer */
}

/*
 * op_error - utility routine to complain about an unresolvable operator