(* $Source$ * $State$ * $Revision$ *) (*$U+ --- enables underscores in identifiers *) program hilo(input, output); type string = array [0..255] of char; var playing : Boolean; seed : integer; { This version of Pascal seems to have no random number generator I can find, so we have to implement our own here. This is a hacked up and probably broken version of the C library generator. } procedure randomise(s : integer); begin seed := s; end; function random(range : integer) : integer; begin seed := (20077 * seed + 12345); random := seed mod range; end; { Pascal doesn't provide string input, so we interface to the _read() syscall and do it manually. } function _read(fd : integer; var buffer : char; count : integer) : integer; extern; function readchar : char; var c : char; dummy : integer; begin c := chr(0); dummy := _read(0, c, 1); readchar := c; end; procedure readstring(var buffer : string; var length : integer); var finished : Boolean; c : char; begin write('> '); length := 0; finished := FALSE; seed := 0; while not finished do begin c := readchar; if (ord(c) = 10) then finished := true else begin buffer[length] := c; length := length + 1; end end; end; procedure getname; var name : string; namelen : integer; i : integer; seed : integer; begin writeln; writeln('Hi there! Before we start, what is your name?'); writeln; readstring(name, namelen); writeln; write('Hello, '); seed := 0; for i := 0 to (namelen-1) do begin write(name[i]); seed := seed + ord(name[i]); end; randomise(seed); write('! '); end; procedure game; var Number : integer; Attempts : integer; guess : integer; begin writeln('See if you can guess my number.'); Number := random(100); Attempts := 0; guess := -1; while guess <> Number do begin Attempts := Attempts + 1; write('> '); readln(guess); if guess < Number then begin writeln; writeln('Try a bit higher.'); end; if guess > Number then begin writeln; writeln('Try a bit lower.'); end; end; writeln; write('You got it right in only ', Attempts:0, ' '); if Attempts = 1 then write('go') else write('goes'); writeln('!'); end; function question: Boolean; var response: char; begin write('> '); readln(response); question := not ((response = 'n') or (response = 'N')); end; begin getname; playing := TRUE; while playing do begin game; writeln; writeln('Would you like another go?'); playing := question; writeln; if playing then write('Excellent! ') else writeln('Thanks for playing --- goodbye!'); end; end.