Method scan_array_lookahead

src/fl/stl/json.cpp.hpp:138–311

Array lookahead scanner - scans array to determine if it can be optimized Returns specialized token (ARRAY_UINT8, etc.) or LBRACKET for slow path Assumes mPos is positioned after '[' character

    // Returns specialized token (ARRAY_UINT8, etc.) or LBRACKET for slow path
    // Assumes mPos is positioned after '[' character
    JsonToken scan_array_lookahead(fl::span<const char>& out_span) {
        if (!mEnableLookahead) {
            return JsonToken::LBRACKET;  // Lookahead disabled
        }

        size_t start_pos = mPos;  // Position after '['

        // Track element types and ranges
        bool has_int = false;
        bool has_float = false;
        bool has_float_beyond_precision = false;  // Track floats > 2^24
        bool has_string = false;
        bool has_bool = false;
        bool has_null = false;
        i64 int_min = fl::numeric_limits<i64>::max();
        i64 int_max = fl::numeric_limits<i64>::min();

        skip_whitespace();

        // Empty array - use slow path
        if (mPos < mLen && mInput[mPos] == ']') {
            out_span = fl::span<const char>();
            return JsonToken::LBRACKET;
        }

        // Scan elements
        while (mPos < mLen) {
            skip_whitespace();

            // Check for array end
            if (mInput[mPos] == ']') {
                break;
            }

            char c = mInput[mPos];

            // Abort on nested structures
            if (c == '[' || c == '{') {
                return JsonToken::LBRACKET;
            }

            // STRING
            if (c == '"') {
                has_string = true;
                mPos++;
                while (mPos < mLen) {
                    if (mInput[mPos] == '\\') {
                        mPos += 2;  // Skip escape sequence
                    } else if (mInput[mPos] == '"') {
                        mPos++;
                        break;
                    } else {
                        mPos++;
                    }
                }
            }
            // NUMBER
            else if (c == '-' || (c >= '0' && c <= '9')) {