Path: utzoo!attcan!uunet!husc6!mailrus!purdue!decwrl!hplabs!ucbvax!decvax.DEC.COM!binder
From: binder@decvax.DEC.COM (A complicated and secret quotidian existence)
Newsgroups: comp.os.cpm
Subject: COMPAS/Turbo/recursion program
Message-ID: <8807021208.AA10306@caliph.dec.com>
Date: 2 Jul 88 12:08:02 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 46

PROGRAM Tryit (INPUT, OUTPUT);
 
{
Recursion program discussed earlier in INFO-CPM Digest - implemented
for Turbo Pascal.
 
The program as originally submitted will not work in *any* correctly
implemented Pascal, because it allows only one byte for the variable
"nextchar".   Declaring the variable inside a procedure doesn't mean
that the variable will have a new space created for it on every call
to the procedure; it only means that the variable is not global.
 
Furthermore, it is necessary to make your Pascal's I/O routines take
characters as they are typed, instead of waiting for a <CR>.   Turbo
does this by using a file read from predeclared file "Kbd".  Then it
is necessary to write the character because file reads do not echo.
}
 
{$A-}
 
{
The above compiler directive enables recursion in the CP/M-80 incar-
nation of Turbo.
}
 
VAR
        index:          INTEGER;
 
        nextchar:       ARRAY [1..100] OF CHAR;  { Allow 100 chars }
 
PROCEDURE Readwrite;
 
BEGIN
  index := index+1;
  READ (Kbd, nextchar [index]);
  WRITE (nextchar [index]);
  IF (nextchar [index] <> ' ') THEN Readwrite;
  WRITE (nextchar [index]);
  index := index-1
END;
 
BEGIN
  index := 0;
  WRITE ('Enter a word, end with a space: ');
  Readwrite
END.