Path: utzoo!attcan!uunet!willett!ForthNet
From: ForthNet@willett.UUCP (ForthNet articles from GEnie)
Newsgroups: comp.lang.forth
Subject: F-PC Forth Tutorial
Message-ID: <1056.UUL1.3#5129@willett.UUCP>
Date: 1 Jun 90 03:45:51 GMT
Organization: Latest link in the ForthNet chain.  (Pgh, PA)
Lines: 71


 Date: 05-30-90 (22:51)              Number: 18 (Echo)
   To: JACK BROWN                    Refer#: NONE
 From: ROY RICE                        Read: NO
 Subj: LESSON3, CONT.                Status: PUBLIC MESSAGE

 Jack: ex.3.7-9:
 \ rarl3b.seq continuation of answers to lesson 3, starting with ex.3.7

 \ ex3.7
 \ Illustration of Number bases and formatted display operators.
 \ modified by rar  05/28/90 20:02:05.74
 : NTABLE ( dn -- )
          CR ."      unsigned"  ."        signed" ."      unsigned"
             ."        signed"  ."      unsigned" ."        signed"
          CR ."       decimal"  ."       decimal" ."        octal "
             ."        octal "  ."         hex  " ."         hex  "
          20 0 DO
               CR
               DECIMAL DUP 13 U.R
                       DUP 13  .R
               OCTAL   DUP 13 U.R
                       DUP 13  .R
               HEX     DUP 13 U.R
                       DUP 13  .R
               1+
               LOOP
               DROP DECIMAL ;

 \ EX.3.8
 : BINARY ( --) 2 BASE ! ;
 :  .H ( n -- ) HEX     . DECIMAL ;  \ Display top number in HEX
 : U.HH ( n -- ) HEX    U. DECIMAL ;  \ Displlay top as unsigned HEX
 :  .O ( n -- ) OCTAL   . DECIMAL ;  \ Display top number in OCTAL
 : U.O ( n -- ) OCTAL  U. DECIMAL ;  \ Display top as unsigned OCTAL
 :  .B ( n -- ) BINARY  . DECIMAL ;  \ Display top number in BINARY
 : U.B ( n -- ) BINARY U. DECIMAL ;  \ Display top as unsigned BINARY

 comment:
 The above definitions end with DECIMAL because we want to reset the
 base to decimal after outputting the number. They could be modified
 to save the current base and restore it after printing the number
 ( I think I saw this in Starting Forth)
 as in this definition to display the number in decimal and then restore
 the base:
 comment;

 :  .D ( n -- ) BASE @ SWAP DECIMAL  . BASE ! ;
 : U.D ( n -- ) BASE @ SWAP DECIMAL U. BASE ! ;

 : BNTABLE ( dn -- )
   CR ." unsigned     signed          unsigned            "
      ." signed     unsigned       signed"
   CR ."  decimal     decimal           binary            "
      ." binary          hex          hex"
          20 0 DO
               CR
               DECIMAL DUP 10 U.R
                       DUP 10  .R
               BINARY  DUP 17 U.R
                       DUP 17  .R
               HEX     DUP 13 U.R
                       DUP 13  .R
               1+
               LOOP
               DROP DECIMAL ;


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