Function classify_array

src/fl/stl/json.cpp.hpp:660–731

enum ArrayType { ALL_UINT8, ALL_INT16, ALL_FLOATS, GENERIC_ARRAY };

ArrayType classify_array(const json_array& arr) {
    if (arr.empty()) return GENERIC_ARRAY;

    bool all_numeric = true;
    i64 min_val = fl::numeric_limits<i64>::max();
    i64 max_val = fl::numeric_limits<i64>::min();
    bool has_float = false;
    bool has_float_beyond_precision = false;

    for (const auto& elem : arr) {
        if (!elem) {
            all_numeric = false;
            break;
        }

        if (elem->is_int()) {
            auto val = elem->as_int();
            if (val) {
                i64 v = *val;
                min_val = (v < min_val) ? v : min_val;
                max_val = (v > max_val) ? v : max_val;
            } else {
                all_numeric = false;
                break;
            }
        } else if (elem->is_float()) {
            has_float = true;
            auto val = elem->as_float();
            if (!val) {
                all_numeric = false;
                break;
            }
            // Check if float is beyond integer precision (>2^24 or <-2^24).
            // Integer biased-exp comparison -- no FP arithmetic (#3022 phase 2).
            const u32 fbits = fl::bit_cast<u32>(*val);
            if (float_bits_magnitude_exceeds_2_24(fbits)) {
                has_float_beyond_precision = true;
            }
        } else {
            all_numeric = false;
            break;
        }
    }

    if (!all_numeric) return GENERIC_ARRAY;

    // Classification
    if (has_float) {
        // If floats are beyond integer precision, don't optimize
        if (has_float_beyond_precision) {
            return GENERIC_ARRAY;
        }
        return ALL_FLOATS;
    }

    // Integer arrays
    if (min_val >= 0 && max_val <= 255) {
        return ALL_UINT8;