* Help with my program @ 1997-02-17 0:00 Doraiapp 1997-02-18 0:00 ` Robert Dewar 0 siblings, 1 reply; 4+ messages in thread From: Doraiapp @ 1997-02-17 0:00 UTC (permalink / raw) I translated a code from java script to ada the code is as follows with text_io; use text_io; with stack; procedure calculator is package int_io is new integer_io(integer); package istack is new stack(integer); use int_io, istack; ch: character; done: exception; function getint(first_digit: character) return integer is n:integer :=0; ch: character :=first_digit; begin loop n :=n * 10 + character'pos(ch) - character'pos('0'); exit when end_of_line; get (ch); end loop; return n; end; procedure process_command(ch: character) is a, b: integer; begin case ch is when '0'..'9' => push(getint(ch)); when 'p' | 'P' => pop(a); put(a); new_line; when '-' => pop(a); put(b); push(b-a); when '+' => pop(a); put(b); pop(a); put(b); push(b+a); when 'q' |'Q' => raise done; when others=> put_line("bad command"); end case; exception when overflow => put_line("stack overflow"); when underflow => put_line("stack underflow"); end process_command; begin loop put(" > "); get(ch); process_command(ch); skip_line; end loop; exception when done => skip_line; end calculator; But my problem is it says b is never assigned a value and also i need to change the integer to a user defined one how do i achieve it? Thanking You Doraiapp PS please also reply at doraiapp@fdusvrt1.fdu.edu ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Help with my program 1997-02-17 0:00 Help with my program Doraiapp @ 1997-02-18 0:00 ` Robert Dewar 1997-02-20 0:00 ` Peter Milliken 0 siblings, 1 reply; 4+ messages in thread From: Robert Dewar @ 1997-02-18 0:00 UTC (permalink / raw) Doriapp says << But my problem is it says b is never assigned a value and also i need to change the integer to a user defined one how do i achieve it?>> The reason it says that b is never assigned a value is that b is never assigned a value, as is clear from your code! I do not understand your confusion ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Help with my program 1997-02-18 0:00 ` Robert Dewar @ 1997-02-20 0:00 ` Peter Milliken 1997-02-21 0:00 ` Robert Dewar 0 siblings, 1 reply; 4+ messages in thread From: Peter Milliken @ 1997-02-20 0:00 UTC (permalink / raw) Robert Dewar wrote: > > Doriapp says > > << But my problem is it says b is never assigned a value and also i need > to change the integer to a user defined one how do i achieve it?>> > > The reason it says that b is never assigned a value is that b is never > assigned a value, as is clear from your code! > > I do not understand your confusion Gee... that was REAL helpful, or perhaps you didn't read the message title? Is this what Mike was talking about several weeks ago when he mentioned how helpful the DJGPP community was and that perhaps we ought to foster the same kind of comraderie (very much paraphrased here, sorry Mike, I believe this was the gist of what you were talking about). I have never seen anyone in the djgpp list respond like this! Dear Doriapp, I assume from a quick look at you code you are trying to implement a RPN Calculator. In which case, something like the '+' case should be: when '+' => -- case assumes that the user has entered two numbers :-) pop(a); pop(b); push(b+a); This will assign the value to 'b' and achieve what I (believe) you want from the exercise. Good Luck Peter -- Peter Milliken _--_|\ peterm@zip.com.au (personal) / \ peterm@cae.com.au (business) \_.--._/ v ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Help with my program 1997-02-20 0:00 ` Peter Milliken @ 1997-02-21 0:00 ` Robert Dewar 0 siblings, 0 replies; 4+ messages in thread From: Robert Dewar @ 1997-02-21 0:00 UTC (permalink / raw) Peter said <<Gee... that was REAL helpful, or perhaps you didn't read the message title? Is this what Mike was talking about several weeks ago when he mentioned how helpful the DJGPP community was and that perhaps we ought to foster the same kind of comraderie (very much paraphrased here, sorry Mike, I believe this was the gist of what you were talking about). I have never seen anyone in the djgpp list respond like this!>> I assumed (perhaps wrongly, but I doubt it) that this was a homework excercise. Peter may *think* that he is helping by doing other peoples homework assignments, but in fact it is harmful. Doing you own work in figuring out homework assignments is one of the most important ways of learning, and you short circuit this if you spoon feed answersw. In this case, the student (again I am assuming this was a student doing a home work excercise), had declared a variable b, which was not otherwise referenced in the program, and could not understand the diagnostic that commented that b was never assigned a value. Peter's help consisted of writing the code for the student that used b, but I don't think that's helpful. Obvsiouly there is a very fundamental lack of comprehension here, and it is not easy to even address this level of lack of comprehension. If you do not understand that variaboles in your program are declared because they are to be used for some purpose, then you are missing some very fundamental grasp of what programs are all about. Supplying incomprehensible code is NOT the way to help some one with this level of confusion. What you need to do is to ask the person WHY they do not understand a message like this, as I did. From that answer you will be able to get to the bottom of the misunderstanding. Remember that the problem here is not to write a calculator program, it is to understand HOW to write a calculator program. it is very easy to help with the first problem (as Peter did), it is MUCH harder to help with the second. A friendly atmosphere in which students can easily get others to write ttheir assignments for them may look nice, and short-sighted students will no doubt find it nice, but it is NOT being helpful to them! RObert ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~1997-02-21 0:00 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 1997-02-17 0:00 Help with my program Doraiapp 1997-02-18 0:00 ` Robert Dewar 1997-02-20 0:00 ` Peter Milliken 1997-02-21 0:00 ` Robert Dewar
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