-/* Extracts a numeric suffix from variable name S, copying it
- into string R. Sets *D to the length of R and *N to its
- value. */
+/* Attempts to break UTF-8 encoded NAME into a root (whose contents are
+ arbitrary except that it does not end in a digit) followed by an integer
+ numeric suffix. On success, stores the value of the suffix into *NUMBERP,
+ the number of digits in the suffix into *N_DIGITSP, and returns the number
+ of bytes in the root. On failure, returns 0. */