expandable arrays, accessing user-defined elements

hanowski · ‎Nov 18, 2004

Guru's,
Anybody got a simple example of accessing custom elements from an expandable array?

For example, this correctly prints out what it should:

typedef struct user_appdata {
int TargetCompID;
int TargetDimID;
int ThisCompID;
float NewDimValue;
} UserAppdata;

ProArray DimChanges;

while ( !feof(fIn) ) {
appdata = (UserAppdata*)calloc(1,sizeof(UserAppdata));
fscanf(fIn,"%d,%d,%f\n",&appdata->TargetCompID,&appdata->TargetDimID,&appdata->NewDimValue);
ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
printf("%d,%d,%f\n",appdata->TargetCompID,appdata->TargetDimID,appdata->NewDimValue);
}

But this doesn't:
i = 0;
while ( !feof(fIn) ) {
appdata = (UserAppdata*)calloc(1,sizeof(UserAppdata));
fscanf(fIn,"%d,%d,%f\n",&appdata->TargetCompID,&appdata->TargetDimID,&appdata->NewDimValue);
ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
printf("%d,%d,%f\n",DimChanges[i].TargetCompID,DimChanges[i].TargetDimID,DimChanges[i].NewDimValue);
i++;
}

Thanks,
Greg

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BobMonat · ‎Nov 19, 2004

Greg,

I often use the ProArray*() functions for working with my own data.

You need to use the family of ProArray*() functions. In particular,
ProArrayAlloc() in place of calloc() and ProArrayFree() in place of free().

Bob

--
Robert A. Monat
Jerand Technical Services, Inc.
http://www.jerand.com
Phone: 317-875-6087 FAX: 317-875-6612 Tollfree(US)888-4JERAND

Greg Hanowski wrote:

>Guru's,
>Anybody got a simple example of accessing custom elements from an expandable array?
>
>For example, this correctly prints out what it should:
>
>typedef struct user_appdata {
> int TargetCompID;
> int TargetDimID;
> int ThisCompID;
> float NewDimValue;
>} UserAppdata;
>
>ProArray DimChanges;
>
>while ( !feof(fIn) ) {
>appdata = (UserAppdata*)calloc(1,sizeof(UserAppdata));
>fscanf(fIn,"%d,%d,%f\n",&appdata->TargetCompID,&appdata->TargetDimID,&appdata->NewDimValue);
>ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
>printf("%d,%d,%f\n",appdata->TargetCompID,appdata->TargetDimID,appdata->NewDimValue);
>}
>
>But this doesn't:
>i = 0;
>while ( !feof(fIn) ) {
>appdata = (UserAppdata*)calloc(1,sizeof(UserAppdata));
>fscanf(fIn,"%d,%d,%f\n",&appdata->TargetCompID,&appdata->TargetDimID,&appdata->NewDimValue);
>ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
>printf("%d,%d,%f\n",DimChanges[i].TargetCompID,DimChanges[i].TargetDimID,DimChanges[i].NewDimValue);
>i++;
>}
>
>Thanks,
>Greg
>
>---
>List name: -
>
>You are currently subscribed to toolkits as: bob@jerand.com.
>To unsubscribe send a blank e-mail to -.
>
>For assistance, email us at - or find other contacts at www.ptcuser.org/org/contacts.html.
>
>PTC/USER and the PTC/USER logo are registered trademarks of PTC/USER, Inc.
>Pro/ENGINEER is a registered trademark of PTC.
>
>Message authors are solely responsible for the content of their posts.
>
>
>

fractal97 · ‎Nov 19, 2004

I think expandable arrays are now obsolete since the Standard Template
Library became a part of any C++ compiler system. You can use vectors for
your needs very conveniently as well as a lot of other features of C++.

>Guru's,
>Anybody got a simple example of accessing custom elements from an
>expandable array?

hanowski · ‎Nov 19, 2004

I left out a few details in the original email for brevity which has
caused confusion. Here is the entire procedure that outputs the correct
values.

//UserAppdata and DimChanges are globals.
typedef struct user_appdata {
int TargetCompID;
int TargetDimID;
int ThisCompID;
float NewDimValue;
} UserAppdata;

ProArray DimChanges;

ProError LoadDimChanges()
{
UserAppdata *appdata;
int i;

ProCharName name;
FILE *fIn;

ProArrayAlloc(0,sizeof(appdata),1,&DimChanges);
strcpy(name,"deploy.lst");
fIn = fopen(name,"r");
i = 0;
while ( !feof(fIn) ) {
appdata = (UserAppdata*)calloc(1,sizeof(UserAppdata));
fscanf(fIn,"%d,%d,%f\n",&appdata->TargetCompID,&appdata->TargetDimID,&appdata->NewDimValue);

ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
printf("%d,%d,%f\n",appdata->TargetCompID,appdata->TargetDimID,appdata->NewDimValue);

//printf("%d,%d,%f\n",DimChanges[i].TargetCompID,DimChanges[i].TargetDimID,DimChanges[i].NewDimValue);

i++;
}
fclose(fIn);
return(PRO_TK_NO_ERROR);
}

If however, I comment out the printf statement and uncomment the other
one, it prints large, incorrect numbers. I'm apparently not casting
something correctly.

Does anybody have a simple example of accessing custom elements from an
expandable array? If not, I will pursue Vin's suggestion of using
standard C++ vectors. (I'm normally a Delphi programmer, not a C
programmer so please excuse my naivety.)

BobMonat · ‎Nov 19, 2004

Greg,

I suggest you check ALL returns from the Pro/E TK functions.

After going through making the changes, I noticed that you had define appdata as a pointer (UserAppdata *appdata) and did not reserve any memory (UserAppdata appdata) for the data. Try this:

ProError LoadDimChanges()
{
UserAppdata appdata;
int i;

ProCharName name;
FILE *fIn;

ProArrayAlloc(0,sizeof(UserAppData),1,&DimChanges);
strcpy(name,"deploy.lst");
fIn = fopen(name,"r");
i = 0;
while ( !feof(fIn) ) {
fscanf(fIn,"%d,%d,%f\n",&appdata.TargetCompID,&appdata.TargetDimID,&appdata.NewDimValue);

ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
printf("%d,%d,%f\n",DimChanges[i].TargetCompID,DimChanges[i].TargetDimID,DimChanges[i].NewDimValue);

i++;
}
fclose(fIn);
return(PRO_TK_NO_ERROR);
}

Greg Hanowski wrote:

>I left out a few details in the original email for brevity which has
>caused confusion. Here is the entire procedure that outputs the correct
>values.
>
>
>//UserAppdata and DimChanges are globals.
>typedef struct user_appdata {
> int TargetCompID;
> int TargetDimID;
> int ThisCompID;
> float NewDimValue;
>} UserAppdata;
>
>ProArray DimChanges;
>
>ProError LoadDimChanges()
>{
> UserAppdata *appdata;
> int i;
>
> ProCharName name;
> FILE *fIn;
>
> ProArrayAlloc(0,sizeof(appdata),1,&DimChanges);
> strcpy(name,"deploy.lst");
> fIn = fopen(name,"r");
> i = 0;
> while ( !feof(fIn) ) {
> appdata = (UserAppdata*)calloc(1,sizeof(UserAppdata));
> fscanf(fIn,"%d,%d,%f\n",&appdata->TargetCompID,&appdata->TargetDimID,&appdata->NewDimValue);
>
> ProArrayObjectAdd((ProArray*)&DimChanges,PRO_VALUE_UNUSED,1,&appdata);
> printf("%d,%d,%f\n",appdata->TargetCompID,appdata->TargetDimID,appdata->NewDimValue);
>
> //printf("%d,%d,%f\n",DimChanges[i].TargetCompID,DimChanges[i].TargetDimID,DimChanges[i].NewDimValue);
>
> i++;
> }
> fclose(fIn);
> return(PRO_TK_NO_ERROR);
>}
>
>If however, I comment out the printf statement and uncomment the other
>one, it prints large, incorrect numbers. I'm apparently not casting
>something correctly.
>
>Does anybody have a simple example of accessing custom elements from an
>expandable array? If not, I will pursue Vin's suggestion of using
>standard C++ vectors. (I'm normally a Delphi programmer, not a C
>programmer so please excuse my naivety.)
>
>---
>List name: -
>
>You are currently subscribed to toolkits as: bob@jerand.com.
>To unsubscribe send a blank e-mail to -.
>
>For assistance, email us at - or find other contacts at www.ptcuser.org/org/contacts.html.
>
>PTC/USER and the PTC/USER logo are registered trademarks of PTC/USER, Inc.
>Pro/ENGINEER is a registered trademark of PTC.
>
>Message authors are solely responsible for the content of their posts.
>
>
>

--
Robert A. Monat
Jerand Technical Services, Inc.
http://www.jerand.com
Phone: 317-875-6087 FAX: 317-875-6612 Tollfree(US)888-4JERAND

hanowski · ‎Nov 19, 2004

We're getting close!

I got a reply from Scott...
"Greg - you need to declare the DimChanges array with some value so that
the C runtime knows the size of its elements to be accessed via []:

UserAppdata** DimChanges;

A ProArray itself should never actually be declared."

That is the key info I was missing. Now it works (almost!). It will
compile ok and print out the first 2 numbers like this...

printf("%d,%d\n",(UserAppdata*)DimChanges[i]->TargetCompID,(UserAppdata*)DimChanges[i]->TargetDimID);

But when I add the 3rd number like this:
printf("%d,%d,%f\n",(UserAppdata*)DimChanges[i]->TargetCompID,(UserAppdata*)DimChanges[i]->TargetDimID,(UserAppdata*)DimChanges[i]->NewDimValue);

The compiler gives this error: "error C2440: 'type cast' : cannot convert
from 'float' to 'UserAppdata *'
There is no context in which this conversion is possible"

hanowski · ‎Nov 19, 2004

It works!

Got the final help again from Scott. "You shouldn't need to do that.
Compiler now knows that DimChanges is a UserAppdata** and so DimChanges[]
is a UserAppdata*.

If you wanted to cast, you'd have to add parentheses to control the order
of operations, currently -> is done before the cast."

So this works:
printf("%d,%d,%f\n",DimChanges[i]->TargetCompID,DimChanges[i]->TargetDimID,DimChanges[i]->NewDimValue);

Thanks everbody (esp Scott) for the help!