yyjson_api_inline bool unsafe_yyjson_is_str_noesc()

in include/yyjson/yyjson.h [4535:4570]

• 24 lines of code
• 9 McCabe index (conditional complexity)

yyjson_api_inline bool unsafe_yyjson_is_str_noesc(const char *str, size_t len) {
#if YYJSON_HAS_CONSTANT_P && \
    (!YYJSON_IS_REAL_GCC || yyjson_gcc_available(4, 4, 0))
    if (yyjson_constant_p(len) && len <= 32) {
        /*
         Same as the following loop:
         
         for (size_t i = 0; i < len; i++) {
             char c = str[i];
             if (c < ' ' || c > '~' || c == '"' || c == '\\') return false;
         }
         
         GCC evaluates it at compile time only if the string length is within 17
         and -O3 (which turns on the -fpeel-loops flag) is used.
         So the loop is unrolled for GCC.
         */
#       define yyjson_repeat32_incr(x) \
            x(0)  x(1)  x(2)  x(3)  x(4)  x(5)  x(6)  x(7)  \
            x(8)  x(9)  x(10) x(11) x(12) x(13) x(14) x(15) \
            x(16) x(17) x(18) x(19) x(20) x(21) x(22) x(23) \
            x(24) x(25) x(26) x(27) x(28) x(29) x(30) x(31)
#       define yyjson_check_char_noesc(i) \
            if (i < len) { \
                char c = str[i]; \
                if (c < ' ' || c > '~' || c == '"' || c == '\\') return false; }
        yyjson_repeat32_incr(yyjson_check_char_noesc)
#       undef yyjson_repeat32_incr
#       undef yyjson_check_char_noesc
        return true;
    }
#else
    (void)str;
    (void)len;
#endif
    return false;
}