Method indexBy

java/lib/src/main/java/io/github/ccxt/base/Generic.java:310–337

(Object a, Object key2)

    }

    public static Map<String, Object> indexBy(Object a, Object key2) {
        Map<String, Object> out = new LinkedHashMap<>();
        List<Object> targetX;

        if (a instanceof List<?>) {
            targetX = (List<Object>) a;
        } else {
            targetX = new ArrayList<>(((Map<String, Object>) a).values());
        }

        for (Object elem : targetX) {
            if (elem instanceof Map<?, ?>) {
                Map<String, Object> m = (Map<String, Object>) elem;
                Object val = m.get((String) key2);
                if (val == null) continue;
                out.put(val.toString(), m);
            } else if (elem instanceof List<?>) {
                int index = Integer.parseInt(String.valueOf(key2));
                List<?> l = (List<?>) elem;
                if (l.isEmpty()) continue;
                if (index < 0 || index >= l.size()) continue;
                Object val = l.get(index);
                if (val == null) continue;
                out.put(val.toString(), elem);
            }
        }
        return out;
    }

    // ---------- groupBy ----------