I have trouble with a library in the works. The code I am using is below:
// C Source File
// Created 6/3/2012; 2:16:41 PM
// Decthyth General 68k Libraries
#include <tigcclib.h>
#define RETURN_VALUE n
void DlgError(const char* msg)
{
DlgMessage("Error",msg,BT_CANCEL,BT_NONE);
}
void WriteToNInt(long n)
{
push_longint(n);
}
void WriteToNFloat(float n)
{
push_Float(n);
}
// Main Function
/*
NOTE: When I say that a function returns a value,
I mean that the value is stored to n.
*/
void _main(void)
{
int mode;
unsigned char a;
ESI argptr=top_estack;
a=GetArgType(argptr);
if (a!=POSINT_TAG)
{
DlgError("First arg must be + int");
return;
}
mode=GetIntArg(argptr);
switch (mode)
{
case 0:
WriteToNFloat(0.1);
}
}
When I compile this example and put in dcth(0):n, it just returns n (no value stored). Do you know what's wrong? Thanks in advance!

Fixed. I edited the code to
// C Source File
// Created 6/3/2012; 2:16:41 PM
// Decthyth General 68k Libraries
#include <tigcclib.h>
//#define RETURN_VALUE n
void DlgError(const char* msg)
{
DlgMessage("Error",msg,BT_CANCEL,BT_NONE);
}
void WriteToNInt(long n)
{
push_longint(n);
VarStore(SYMSTR("n"),STOF_ESI,0,top_estack);
}
void WriteToNFloat(float n)
{
push_Float(n);
VarStore(SYMSTR("n"),STOF_ESI,0,top_estack);
}
// Main Function
/*
NOTE: When I say that a function returns a value,
I mean that the value is stored to n.
*/
void _main(void)
{
int mode;
unsigned char a;
ESI argptr=top_estack;
a=GetArgType(argptr);
if (a!=POSINT_TAG)
{
DlgError("First arg must be + int");
return;
}
mode=GetIntArg(argptr);
switch (mode)
{
case 0:
WriteToNFloat(0.1);
break;
}
}
(again, thanks!)

Code: [Select]

#define RETURN_VALUE nOh, it's not that simple: RETURN_VALUE is an argument-less macro

If you want to store data to a variable, you need to either use a high-level function such as VarStore, or do it the hard way, by building the variable yourself: HeapAlloc + SymAdd + etc. (lots of error checking), write the two size bytes, write the variable's contents (here, nine out of ten bytes from the float) and end tag (0x23 FLOAT_TAG).

The docs refer to using a variable name as an argument to RETURN_VALUE to automatically store the last value pushed to the expression stack to the variable, and I even seem to remember using this myself once. Has this changed?

Maybe you either need to push END_TAG before pushing your arguments or delete everything up to the END_TAG, or something like that. For instance, I had a very small program that returns the value of FiftyMsecTick (which I used for more precise timing in TI-BASIC programs) that looked like this:

/* Program creation date:  2007/04/23
   Compilation command used:  tigcc -O3 -Wall tick.c
*/

#define MIN_AMS 200
#define RETURN_VALUE tmrval

#include <args.h>
#include <estack.h>
#include <system.h>

void _main(void) {   
    // Return result:
    while (GetArgType (top_estack) != END_TAG)  // Clean up arguments
        top_estack = next_expression_index (top_estack);
    top_estack--;
    push_longint(FiftyMsecTick);
}

I don't remember where I got the “clean up arguments” code, but I'm sure I pasted it from somewhere rather than figure out how to write it myself.

My other (very small test program) I could find like this added its own END_TAG, like this:

// Test routine--returns the string "Hello, world!"

#define RETURN_VALUE ret

#define USE_TI89

#include <args.h>
#include <estack.h>
#include <vat.h>

void _main(void)
{
  ESI argptr = top_estack;
  push_END_TAG ();
  push_zstr("Hello, world!");
}

A quick test in TIEmu seemed to show that this program works.

I don't remember where I got the “clean up arguments” code, but I'm sure I pasted it from somewhere rather than figure out how to write it myself.

Yup, for instance from one of the examples on the htretval.html page I linked above
I saw the snippet yesterday evening, but at the time, I didn't remember that GetIntArg and friends do not modify top_estack... So yeah, at a minimum, the code snippet from the first post needs to clean up the arguments, before pushing the result.

while (!(*temp3==TRUE_TAG||*temp3==LIST_END_TAG||*temp3==END_TAG));||*temp3==LIST_END_TAG is wrong for two reasons:
* programs are not supposed to see that internal tag from ExtTags when dealing with expressions - if they do, chances are that the calculator is in an unstable state;
* LIST_END_TAG has the same value as NEGINT_TAG (from Tags), so your code will spuriously store "true" to n if the list contains any negative integer.
=> retry without the middle comparison against LIST_END_TAG

Let's look at the code more thoroughly...

Oh, yeah, you're not entering the list at all, because you call next_expression_index on temp3 = argptr when argptr points to the LIST_TAG.
What about
case 19:
a=GetArgType(argptr);
if (a!=LIST_TAG)
{
DlgError("Arg 2 must be list");
return;
}
temp3=argptr - 1; // Skip the LIST_TAG
do
{
temp3=next_expression_index(temp3);
} while (!(*temp3==TRUE_TAG||*temp3==END_TAG));
WriteToNBool(*temp3==TRUE_TAG);?

* it needs to be a while loop, because the empty list is END_TAG LIST_TAG (E5 D9), in which case you don't want to enter the loop;
* you need to remove the comparisons against LIST_START_TAG, which are even more noxious than the comparisons against LIST_END_TAG in one of your previous code snippets (as LIST_START_TAG collides with positive integers, while LIST_END_TAG collided with negative integers). But that's not the reason why you're seeing an infinite loop.

I'll test your code.

EDIT: you put a ";" at the end of the "while" line in cases 19 and 20, which does definitely cause an infinite loop if the condition for escaping it is not met

How does ARB_REAL_INT work?

See push_next_arb_int / push_next_arb_real and ARb_int_count / ARb_int_real

Edit: Now I need to write from a TI-Basic list to a long array... solutions, anyone?

What you wrote, or init_list_indices ( http://debrouxl.github.com/gcc4ti/estack.html#init_list_indices ).
Note that unless you're compiling GCC4TI from Git (which is now quite a streamlined process under *nix for the "experimental" branch, https://github.com/debrouxl/gcc4ti/tree/experimental ), init_list_indices is in unknown.h. Documenting that function and moving it to estack.h was done in July 2009, right after the severely outdated current release (June 2009...).