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It looks like you have defined `contents' twice, maybe thats the
core of your issue?<br>
<br>
On 08/03/2010 05:07 PM, <a class="moz-txt-link-abbreviated" href="mailto:iam_here@aol.in">iam_here@aol.in</a> wrote:
<blockquote
cite="mid:8CD0177C0553693-215C-283C@webmail-d071.sysops.aol.com"
type="cite"><font face="arial" size="2" color="black"><br>
<div style="padding: 10px; margin: 0px; border-style: none;
background-color: transparent; font-family: arial; font-size:
10pt; color: black;">
<div>
<div><span class="Apple-style-span" style="font-size:
small;"><span class="Apple-style-span" style="font-size:
small;">Hello I have a program consists of two tasks.
My first task works fine. In second task I have to
create a new chip as soon as the new card has been
created.</span>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">I am giving you sample run for the idea</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">
<div>==> (define c1 (a-chip))</div>
<div>c1</div>
<div>==> (contents c1)</div>
<div>0</div>
<div>==> (charge c1 10.00)</div>
<div>done</div>
<div>==> (contents c1)</div>
<div>10.0</div>
<div>==> (discharge c1 9.34)</div>
<div>9.34</div>
<div>==> (contents c1)</div>
<div>0.66</div>
<div>==> (discharge c1 0.67)</div>
<div>no</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div><br>
</div>
<div>==> (define alan (a-card 432776 1904))</div>
<div>alan</div>
<div>==> (define bill (a-card 1 95))</div>
<div>bill</div>
<div>==> (inserted bill 96)</div>
<div>no</div>
<div>==> (contents bill)
// HAVING PROBLEM IN THIS</div>
<div>ERROR: Not inserted</div>
<div>==> (inserted bill 95)</div>
<div>done</div>
<div>==> (contents bill)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>//PROBLEM IN THIS</div>
<div>0</div>
<div>==> (free bill)</div>
<div>done</div>
<div>==> (new-pin bill 96)</div>
<div>no</div>
<div>==> (inserted bill 95)</div>
<div>done</div>
<div>==> (new-pin bill 96)</div>
<div>done</div>
<div>==> (account-number bill)</div>
<div>1</div>
<div>==> (free bill)</div>
<div>done</div>
<div>==> (account-number bill)</div>
<div>1</div>
</div>
<div><br>
</div>
<div>I AM NOT ABLE TO WORK OUT CONTENTS IN TASK 2..</div>
<div>I have already created contents in task 1. Do I
have to create it again.</div>
<div><br>
</div>
<div>let me summarise my problem- </div>
<div>when I write (contents card) it has to work all
the three procedures defined in task one contents,
charge and discharge.</div>
<div>I have given some efforts but don't worth it.</div>
<div><br>
</div>
<div>Any help will be appreciated</div>
<div>thanks</div>
<div><br>
</div>
</span>
<div><span class="Apple-style-span" style="font-size:
small;">;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;TASK
1;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">(define (a-chip)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (let ( (balance 0) )</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (define (the-chip op)</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">(sequence</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (cond ((eq? op 'contents)
(lambda () balance))</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> ((eq? op 'charge)
charge)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> ((eq? op 'discharge)
discharge)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (else (error "chip: unknown
operation" op))</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> )</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">'nononon)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> )</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (define (charge amount)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (set! balance amount)</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">'done</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> )</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (define (discharge amount)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> (if (> (- balance amount) 0)</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">(
sequence (set! balance (- balance amount))</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">amount)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> </span><span class="Apple-tab-span"
style="white-space: pre;"><span
class="Apple-style-span" style="font-size:
small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">'no</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> )</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> the-chip</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"> )</span></div>
<div><span class="Apple-tab-span" style="white-space:
pre;"><span class="Apple-style-span"
style="font-size: small;"> </span></span><span
class="Apple-style-span" style="font-size: small;">"mjuu"</span><span
class="Apple-tab-span" style="white-space: pre;"><span
class="Apple-style-span" style="font-size:
small;"> </span></span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">)</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">(define (charge chip amount) ((chip
'charge) amount))</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">(define (discharge chip amount) ((chip
'discharge) amount))</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">(define (contents chip) ((chip 'contents)
))</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;"><br>
</span></div>
<div><span class="Apple-style-span" style="font-size:
small;">
<div>;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;TASK
2;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;</div>
<div><br>
</div>
<div><br>
</div>
<div>(define (a-card account tpin)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>( let (
(chip #f))</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span> (define
(the-card request)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>(cond ((eq?
request 'inserted)<span class="Apple-tab-span"
style="white-space: pre;"> </span>inserted)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span> ((eq?
request 'free)<span class="Apple-tab-span"
style="white-space: pre;"> </span> free)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span> ((eq?
request 'new-pin)<span class="Apple-tab-span"
style="white-space: pre;"> </span>new-pin)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span> ((eq?
request 'account)<span class="Apple-tab-span"
style="white-space: pre;"> </span>( lambda ()
account))</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span><span
class="Apple-tab-span" style="white-space:
pre;"> </span> (else (error "card:
unknown operation" request))</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>)</div>
<div>)</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>(define (inserted pin )</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>(if (= pin
tpin)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>(sequence
(set! chip #t)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span></div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span></div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span></div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>'done)<span
class="Apple-tab-span" style="white-space:
pre;"> </span></div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>'no))</div>
<div><br>
</div>
<div>(define (free)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>(sequence
(set! chip #f)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>'done)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>)</div>
<div><br>
</div>
<div><br>
</div>
<div>(define (new-pin new)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>(if (eq? #t
chip )</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>(sequence
(set! tpin new )</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>'done)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>'no)</div>
<div>)</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span></div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span></div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>the-card</div>
<div><span class="Apple-tab-span"
style="white-space: pre;"> </span>)</div>
<div> )</div>
<div><br>
</div>
<div><br>
</div>
<div>(define (contents card)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>((card 'contents)))</div>
<div>(define (pupu card)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>((card 'pupu)))</div>
<div>(define (inserted card pin)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>((card 'inserted ) pin))</div>
<div>(define (free card)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>((card 'free)))</div>
<div>(define (new-pin card new)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>((card 'new-pin) new))</div>
<div>(define (account-number card)<span
class="Apple-tab-span" style="white-space:
pre;"> </span>((card 'account)))</div>
<div><br>
</div>
</span></div>
</div>
</span></div>
</div>
</div>
</font>
<pre wrap="">
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</blockquote>
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