From: "Glenn M. Lewis" <glenn@...>
Date: 2003-02-19T02:38:02+09:00
Subject: Re: Question about SWIGing a C++ array for Ruby

I think I solved this one with a hack... in the CSIChart.h file,
I put:
=================
#ifndef SWIG
   CSITick* ticks;
#endif
=================
and then I added to the RubyStock.i file:
========================================================================
%include "CSIChart.h"
%extend CSIChart {
   CSITick* ticks(int index) {
     while (index < 0) index += self->numticks;  // wrap-around
     if (index >= self->numticks) {
       printf("ERROR: index (%d) out of range for ticks array: 0...%d\n",
              index, self->numticks);
       return 0;
     }
     return &self->ticks[index];
   }
};
========================================================================
This works, but is there a way to turn this into a Ruby Array
so that 'ticks' could be accessed with the '[]' notation?

Thanks!
						-- Glenn Lewis

Glenn M. Lewis wrote:
>     I've got these C++ classes:
> 
> class CSITick {
>  public:
>   unsigned long date;
>   float open;
>   float high;
>   float low;
>   float close;
>   long volume;
> };
> class CSIChart {
>  public:
>   CSITick* getTick(long date);  // CAN return NULL!!!
>   CSITick* ticks;
>   long numticks;
>   //...
> };
> 
> 
> where 'ticks' is an array of CSITick's, created with:
>   ticks = new CSITick[numticks];
> 
>     I can't seem to figure out how to make SWIG access this
> 'ticks' pointer as if it were an Array in Ruby, with length
> equal to numticks.  I would like it to be read-only as well.
> 
>     The '%typemap' SWIG directive doesn't seem right, as
> this is the only place where I want to treat a CSITick* as an
> Array... otherwise, I would like a CSITick* to just be a reference
> to an instance of CSITick.  Am I making any sense?
> 
>     I'm using SWIG-1.3.17 and ruby 1.6.8 (2002-12-24) [i586-mswin32]
> on Windows XP.
> 
>     Thanks!
>                         -- Glenn Lewis