Synopsis:
   $ascii(<integer list>)
   $chr(<character list>)

Technical:
   This pair of function is used to convert between 8-bit characters and
   their numeric equivalent (dependent on your locale).  The $ascii()
   function converts from numeric to character, and $chr() converts from
   characters to their numeric values.

   For $ascii(), integers in the range 0..255 are accepted for input.  For
   $chr() any arbitrary list of characters is accepted.

Practical:
   These functions are used to convert from character values to their
   numeric values, and back.  One common use for these is to insert control
   character into text without having to actually type them in; or to
   check the case of a character.

Returns:
   ascii: space-delimited list of integer values
   chr:   concatenated list of characters

Examples:
   /* assume iso8859-1 character set */
   $ascii(abcABC)                     returns "97 98 99 65 66 67"
   $chr(1 2 3)                        returns "ABC" (ctrl-A, -B, -C)
   $chr($ascii(abcABC))               returns "abcABC"

Other Notes:
   Some characters with the high bit set will return negative numeric
   values from $ascii().  Add 256 to this negative value to get its
   positive equivalent.  The $chr() function will accept either.