Reads the next character from the input stream Stream and unifies its ASCII
code with Ascii.
+Stream
Integer (stream number) or Atom (reserved or user-defined symbolic stream name).
?Ascii
Integer.
Description
Takes the next character from the open input stream Stream and unifies
its integer ASCII code (in the range 0 to 255) to Ascii. ASCII codes
for the non-printable characters (i.e. control characters) are also
acceptable.
Fail Conditions
Fails if Ascii does not unify with the next character from the buffered
input stream Stream.