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digitalmars.D.learn - PyD-like wrapping for Excel/VBA and Julia?

reply "Laeeth Isharc" <laeethnospam nospamlaeeth.com> writes:
I have a bunch of D functions I would like to make available to 
Excel (and possibly Julia) without having to write wrappers for 
each function individually.

For Excel, I think one needs two levels of wrapper - one is to 
create a C style interface [using extern(Windows) calling 
convention, and pointers to doubles or structs rather than 
dynamic arrays], and the second is to write the VBA wrapper that 
calls the C interface.  (There may be more efficient purer ways 
of doing this, but I don't wish to spend time learning Excel 
internals/object models, and I know my route will work reasonably 
well).

So a very simple D function:
double test(double[] inp,  ref double[] oup)
{
	double sum=0.0;
	oup.length=inp.length;
	foreach(i;0..inp.length)
	{
		oup[i]=inp[i]*inp[i];
		sum+=oup[i];
	}
	return sum;
}

and my first attempt at a wrapper:

extern(Windows) double vbwrap_test(double* inp,size_t 
num_inp,double* oup,size_t num_oup)
{
	double[] arg_inp;
	arg_inp.length=num_inp;
	double[] arg_oup;
	arg_oup.length=num_oup;
	foreach(arg;0..num_inp)
	{
		arg_inp[arg]=inp[arg];
	}

	foreach(arg;0..num_oup)
	{
		arg_oup[arg]=oup[arg];
	}

	return test(arg_inp,arg_oup);
}

I didn't yet write the bit that copies the result from test back 
to the calling double*.

Slowly learning metaprogramming/CTFE in D, and the code above was 
generated from the function definition by some horrible looking D 
code, ready to place into a string mixin.  I need to make it more 
general (to accept structs etc), and write the VBA wrapper 
generation too.

But if anyone has any useful pointers or suggestions or would 
like to help, do let me know.  I guess this project could be of 
broader application since in the financial and other sectors 
people still are stuck with Excel as a front end in many cases, 
for better or for worse.

I will look at LuaD and PyD and Adam's web.d for inspiration..

Julia was just something to think about further down the line.  I 
haven't used it much yet.


Thanks.


Laeeth.
Dec 18 2014
next sibling parent reply Ellery Newcomer <ellery-newcomer utulsa.edu> writes:
On 12/18/2014 12:41 PM, Laeeth Isharc wrote:

 I have a bunch of D functions I would like to make available to Excel
 (and possibly Julia) without having to write wrappers for each function
 individually.


I've thought about refactoring the reflection parts of pyd into a 
reusable library for e.g. resurrecting RuD. Come to think of it, that 
would probably be necessary for supporting pypy.

It'd be a heck of a lot of work, though.



For your wrapper, you can probably do something like

extern(Windows) double vbwrap_test(double* inp,size_t num_inp,double* 
oup,size_t num_oup)
{
     return test(inp[0 .. num_inp], arg_oup[0 .. num_oup]);
}

with .dup sprinkled in as you see fit. And you don't need to explicitly 
copy the results back! Might need to take the ref off oup in test..
Dec 18 2014
parent "Laeeth Isharc" <laeethnospam spammenot_laeeth.com> writes:
On Friday, 19 December 2014 at 01:59:05 UTC, Ellery Newcomer 
wrote:

 On 12/18/2014 12:41 PM, Laeeth Isharc wrote:

 I have a bunch of D functions I would like to make available 
 to Excel
 (and possibly Julia) without having to write wrappers for each 
 function
 individually.


 I've thought about refactoring the reflection parts of pyd into 
 a reusable library for e.g. resurrecting RuD. Come to think of 
 it, that would probably be necessary for supporting pypy.

 It'd be a heck of a lot of work, though.



 For your wrapper, you can probably do something like

 extern(Windows) double vbwrap_test(double* inp,size_t 
 num_inp,double* oup,size_t num_oup)
 {
     return test(inp[0 .. num_inp], arg_oup[0 .. num_oup]);
 }

 with .dup sprinkled in as you see fit. And you don't need to 
 explicitly copy the results back! Might need to take the ref 
 off oup in test..


Thanks for the pointers, Ellery.

What was RuD?  RubyD?



There may be more efficient purer ways of doing this, but I
 don't wish to spend time learning Excel internals/object 
 models, and I know my route will work reasonably well).


ActiveX is not internal to Excel. Being a generic component 
interface, it's available over almost all microsoft technologies.


True, but how does that help me right a function I can call from 
a spreadsheet?  I had understood ActiveX was for scripting the 
app, but not so useful if you want to write a function  that can 
be entered in a cell formula.  So it seems to me that ActiveX 
doesn't create an obvious way to avoid  writing a C API wrapper 
and then VBA wrapper around that.
Dec 19 2014
prev sibling parent "Kagamin" <spam here.lot> writes:
On Thursday, 18 December 2014 at 20:41:39 UTC, Laeeth Isharc 
wrote:

 (There may be more efficient purer ways of doing this, but I 
 don't wish to spend time learning Excel internals/object 
 models, and I know my route will work reasonably well).


ActiveX is not internal to Excel. Being a generic component 
interface, it's available over almost all microsoft technologies.
Dec 19 2014