-#define IS_ASCII(c) (((c) & 0x80) == 0)
-#define IS_BASE64(c) ((IS_ASCII (c) && base64_char_to_value[c] >= 0) || c == '=')
-
-/* Get next character from the string, ignoring whitespace. C should
- be int, and will contain the next character, \0 if end is reached,
- or -1 if a non-ws non-base64 character is read. */
-#define NEXT_BASE64_CHAR(c, p) for (;;) { \
+/* Store in C the next non-whitespace character from the string, or \0
+ when end of string is reached. */
+#define NEXT_CHAR(c, p) do { \