String Initializing problem

[Robert E. Carneal]

Hello, problem that has caused me to lose a handful of hair.

Here is my code:

Temp2$="" :' I am *Trying* to make NewWord EMPTY
for Kount = 1 to 6
Temp2$ = Temp2 + mid$(OldWord,Kount,1)
next Kount


In my case, Temp2$ never initializes to nothing. Its string
length is -28672! I tried printing Temp2$ to the screen and it
prints one of the characters from Character #33 to Character #90
(On an Ascii table).

Is Temp2$ a reserved word by Powerbasic? I tried using other
variables, but I end up with the same contents whenever I go to
"build" my new word. Any suggestions? I tried using Watch on
debug, and the puzzler is Temp2$ stays empty right up until the
line after Temp2$ = "" I have no idea where it is getting
its data- I don't have files open.

Thanks for any input. Yes, I will post the code, but I would
rather wait until requested to do so. It is currectly 92 lines,
not too bad yet, but not finished either.

Robert

------------------

[Don Ewald]

Greetings Robert!

I played a little with your code:

Temp2$="cisaBrewoP"
OldWord$="PowerBasic"

Temp2$=""

FOR Kount% = 1 TO 6
  PRINT Temp2$, LEN(Temp2$)
  Temp2$ = Temp2$ + MID$(OldWord$,Kount%,1)
NEXT Kount%

...and met with success, seemingly. Here's the output of the above stated code:

               0 
P              1 
Po             2 
Pow            3 
Powe           4 
Power          5

...the output shows that the Temp2$ variable was reinitialized and then padded with new information. The only thing that I noticed in your code:

1. Line One has a colon before your comment. The colon isn't needed.
2. You've initialized the Temp2$ to ""; but then you use the variable Temp2 in line three.
3. I'm a fan of using $'s, %'s, &'s and such in my programs. It appears that you arbitrarily do; unless those unstated ones are global variables.


------------------
Don Ewald
mailto:[email protected][email protected]</A>

[Ian Cairns]

Try using the $ string identifier in all places.
OldWord is, by default, an integer.
Slight changes make it work for me in PB 3.2
To say why it wasn't working for you, I would have to see more code.

OldWord$ = "aBcDeFgHiJkL"
Temp2$="" ' I am *Trying* to make NewWord EMPTY
for Kount% = 1 to 6
  Temp2$ = Temp2$ + mid$(OldWord$,Kount%,1)
next Kount%
print Temp2$

regards,
(Don beat me to the posting.)

[This message has been edited by Ian Cairns (edited September 10, 2001).]

[Mike Luther]

I tried it with version 19 of PB 3.5 for DOS and it won't
even compile as run in a DOS-VDM in OS/2.

It, I think, correctly traps the Temp2$ = Temp2 portion of the
line at the place where there is no string ($) with an error
421, "String operand expected" here.

On the extra colon ":" in that first line, you may fault me amd
chew me out if you like, but I've seen that un-needed colon
also produce corrupt compiled code where some curious combination
of text is beyond that remark line apostrophe, long ago and far
away. That's two years ago or so and I can't recall what the
other text was in the remark line which caused it. I seem to
recall that the difference between using "REM" and "'" at that
point was a factor in evoking the error.

At any rate removing the un-needed ":" broke the error. This
issue was one reason I made the decision to never use more
than one statement on a line in PowerBASIC, although, in
theory, that shouldn't make any difference, in general in your
coding style choice ...

------------------
Mike Luther
[email protected]

[Bob Zale]

Originally posted...

On the extra colon ":" ... but I've seen that un-needed colon
also produce corrupt compiled code...

I hope that noone will follow this advice, as it simply does not apply to PowerBASIC in any fashion. In this context, the result is 100.00%, absolutely identical with or without the colon. Please don't be misled into making your programming more difficult than it ought to be.

Regards,

Bob Zale
PowerBASIC Inc.


------------------

[Clay Clear]

I use colons in my code EXTENSIVELY, and have NEVER had a problem
with it, either in compile time or runtime, in both PB/DLL 6.0 and
PB/DOS 3.5.

Regards,


------------------
Clay C. Clear

mailto:[email protected][email protected]</A>

Clay Clear's Software

[Robert E. Carneal]

Thanks for the replies guys.

As for the colon causing the problem, blame my prof. She
wanted multiple statements on a line, the colon before each
comment, etc. It is a habit I can break if I need to.

Would the fact I am using the full Dos window (not just a small
Dos box) in Windows ME be a clue?

I am going to get out of here, and CnP the code and compare it
my own. In my mind (except for the $'s, %'s, &'s) the code is
close. I will come back and let you know.

In my program, I had Temp2$ throughout, not Temp2. I mis-typed
here. My fault there.

Thanks for the help!

------------------

[Lance Edmonds]

To me, it sounds more like you have a memory corruption issue due to overwriting past an array boundary or similar, or you have some variable-class problems.

I assume that this is part of a {much} larger program right? The first thing you need to do is add the line $ERROR ALL ON to the top of the code and run it again.

Chances are, the real problem is elsewhere in the code.

Please try this and let us know what else you discover...

Thanks!

PS: I would doubt VERY MUCH that Windows ME has anything to do with this problem!

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Robert E. Carneal]

Guys- no go for me. This time, I CnP'd the troublesome code for
you to see firsthand. Temp2$ *still* gives me a weird contents
even after initializing to "". The copied code is at the bottom
of this post.

Explanation: This is a word unjumbler. It accepts an entry, and
mathematically determines how many ways there are to rearrange
the given letters.

The array PossOrd stores numbers containing ways to arrange
letters. For a 4 letter word (Let's use "SKED" which unscrambles
to DESK.) The original order is 1234 (1 represents the first
letter, 2 represents the second letter, and so on). The program
will not accept the number such as 3224, because it makes no use
of the letter "S" and uses "K" twice.

PossOrd is an array that contains ways the word can be the
arranged. Four a 4 letter word, there are 24 ways to arrange
it and hence 24 numbers get generated. For the curious, a
seven-letter word has 5040 ways it can be arranged, so I have
set my array to hold 5100 numbers at the most.

I am using the full Dos window in Windows Me, if that is a clue,
and using an AMD 850.

Now, assume the value of PossOrd(I6) to be 1243, Temp2$ should
end up with "SKDE" (which is not valid, but I will check for
that later.)

Hey guys, none of you have to do this; I will admit I am very
stumped and could use someone pointing out my errors. I took
out all of the comments to see if that would work, but didn't
seem to help any.


Immediately after setting Temp2$ to "", the debugger shows the
contents of Temp2$ to be horribly long, I think it is in excess
of 1200 characters! It begins a pattern of repeating after
so many characters.


Initial values from earlier in program:
PossOrd(I6) = 1243
WordLen = 4, determined earlier in program
TestWord$ = "SKED"

Then the first time through, I get: (Should get, but don't)

I6 = 1
PossOrd(i6) = 1243
Possible$ = "1243"
I7 = 1
GetCharNo = 1 ' get the first letter in TestWord$
Temp2$ = "S"

Second time through
I6 = 1
PossOrd(i6) = 1243
Possible$ = "1243"
I7 = 2 ' get the second letter in TestWord$
GetCharNo = 2
Temp2$ = "SK"

Third time through
I6 = 1
PossOrd(i6) = 1243
Possible$ = "1243"
I7 = 3 ' get the third letter in TestWord$
GetCharNo = 3
Temp2$ = "SKD"

Fourth time through (Last in this example)
I6 = 1
PossOrd(i6) = 1243
Possible$ = "1243"
I7 = 4 ' get the first letter in TestWord$
GetCharNo = 4
Temp2$ = "SKDE"

'
' Create New List of possible orders- MOST words will be invalid
for i6 = 1 to Pk
Temp2$=""
Possible$=str$(PossOrd(I6))
Possible$=Trim$(Possible$)
for i7 = 1 to WordLen
GetCharNo=val(mid$(Possible$,i7,1))
Temp2$=Temp2$+mid$(TestWord$,ChetCharNo)
next i7
print Temp2$
'gosub ValidWordQ
next i6


ValidWordQ:
'not written yet

end


------------------

[Robert E. Carneal]

For Lance Edmonds.

<Copy from Lance>
I assume that this is part of a {much} larger program right?
The first thing you need to do is add the line $ERROR ALL ON
to the top of the code and run it again.
<End copy>

That was surprising, but being a Powerbasic newbie, I am not
sure what it means. It said:

.... If this happens on a DIM or REDIM, an attempt was made to
allocation more than 64K of memory without the HUGE option.


"HUGE" option? That is totally new to me. Ok, Just tried it and ]
it stops at the same point with the same error. Should I just
re-write this from scratch?

Robert

------------------


[This message has been edited by Robert Carneal (edited September 10, 2001).]

[Ian Cairns]

Robert,
1.The line incrementing temp2$ is adding more than 1 character at a time.
MID$() requires a variable indicating length, otherwise you get a
substring from the extraction point onwards. This can become too large
very quickly and might account for the error message.

2.You can combine the ltrim$() and str$() operations.

A minimal functional example is:

DIM possOrd(1:5100)
possOrd(1) = 1234
possOrd(2) = 1342
possOrd(3) = 1432
possOrd(4) = 1423
WordLen = 4  '  determined earlier IN program
TestWord$ = "SKED"
Pk = 4

FOR i6 = 1 TO Pk
  Temp2$=""
  Possible$=LTRIM$(STR$(PossOrd(I6)))
  FOR i7 = 1 TO WordLen
    GetCharNo=VAL(MID$(Possible$,i7,1))
    Temp2$=Temp2$+MID$(TestWord$,GetCharNo,1)
  NEXT i7
  PRINT Temp2$
NEXT i6

regards,

------------------
[email protected]

[Doris Leeyin]

Bob Zale is correct.
There is no difference by adding a ":" or not at the end of a
line (you have to know what is the end of the line).
Power Basic lives upto what it says on the documentations.




------------------

[Doris Leeyin]

Robert,
-------------------------------------------------------------
original post.....

'Create new list of possible orders -- Most words will be invalid

FOR I6 = 1 TO PK
TEMP2$=""
POSSIBLE$=STR$(POSSORD(I6))
POSSIBLE$=TRIM$(POSSIBLE$)
FOR I7 = 1 TO WORDLEN
GETCHARNO=VAL(MID$(POSSIBLE$,I7,1))
TEMP2$=TEMP2$+MID$(TESWORD$,CHECHARNO)
NEXT I7
PRINT TEMP2$
NEXT I6
-----------------------------------------------------------------
Your problem is the value of numeric variables.
Try add a line "PRINT PK;WORDLEN;CHECHARNO"
before "FOR I6 = 1 TO PK"
and
add a line "PRINT GETCHARNO;CHECHARNO:PRINT TEMP2$:PRINT LEN(TEMP2$)"
before "next I7"

Regards

------------------

[Lance Edmonds]

Originally posted by Robert Carneal:
For Lance Edmonds.
<Copy from Lance>
The first thing you need to do is add the line $ERROR ALL ON to the top of the code and run it again.
<End copy>

That was surprising, but being a Powerbasic newbie, I am not sure what it means. It said:

.... If this happens on a DIM or REDIM, an attempt was made to allocation more than 64K of memory without the HUGE option.

By this I assume that you got an error? From the description, you got an out of range error (Error #9). This means you are probably trying to access an array past is boundary, as I predicted in my last message.

Which line of code did the error actually occur on? That should give you the clue you need.

Doris has also given you a good debugging tip here... add a PRINT line into the loop (assuming that is where is fails) to display the values and variables you are working with.

"HUGE" option? That is totally new to me. Ok, Just tried it and ]
it stops at the same point with the same error.

That is not really applicable to your solution I think, since you are dealing with 5100 subscripts or less.

Should I just re-write this from scratch?

Probably not, since you really only need to debug the existing code a little.

In summary, based on the Error 9, and not knowing which line of code is failing, I'd take a stab at a few likely causes of the failure:[list=1][*] The variable "pk" is much larger than the number of subscripts in the PossOrd() array.[*] The typo in the MID$() line refers to a variable "chetcharno" whereas the other lines refer to "getcharno" [/list=a]
Finally, there is one shortcoming with the code. You set the size of WORDLEN in the earlier piece of code somewhere, but POSSSIBLE$ may be smaller since you use TRIM$(). You may want to change the FOR loop to the exact length, rather than use WORDLEN.

For example:

for i6 = 1 to Pk
  Temp2$=""
  Possible$=str$(PossOrd(I6))
  Possible$=Trim$(Possible$)
  for i7 = 1 to [b]len(Possible$)[/b] ' Was "WORDLEN"
    GetCharNo=val(mid$(Possible$,i7,1))
    Temp2$=Temp2$+mid$(TestWord$,[b]GetCharNo[/b]) ' Was "ChetCharNo"
  next i7
  print Temp2$
  'gosub ValidWordQ
next i6

Anyway, this is mostly speculation, but I hope it helps!

PS: you can use $DIM ALL to help with variable name errors such as I mentioned in point #2 above.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>