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digitalmars.D - Writing a library

reply Mn <mn mailinator.com> writes:
Hello World!

Is it possible to write a library in D that can be used by other programming
languages? And if yes, how to do it? I can think of two ways of "using" a lib
in general:

1. The OOP way: use a class of the lib, then its functions, dunno how its
called.
2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

I am only interested in the more popular languages like C, C++, Java, C#, PHP.

Greetings and thank you.
-- Mn
Feb 16 2007
parent reply "Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:
"Mn" <mn mailinator.com> wrote in message 
news:er492f$1sti$1 digitalmars.com...

 Hello World!

 Is it possible to write a library in D that can be used by other 
 programming languages? And if yes, how to do it? I can think of two ways 
 of "using" a lib in general:

 1. The OOP way: use a class of the lib, then its functions, dunno how its 
 called.
 2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

 I am only interested in the more popular languages like C, C++, Java, C#, 
 PHP.

 Greetings and thank you.
 -- Mn



No other languages understand D calling or mangling conventions, but D can 
make functions with C, Windows, and Pascal calling conventions.  If you just 
do something like:

extern(C) export void func(int x) { ... }

You can then, maybe, make a DLL or something out of it which can be called 
from virtually any other mainstream language, since most things understand 
the C calling convention.
Feb 16 2007
next sibling parent Mn <mn mailinator.com> writes:
Jarrett Billingsley Wrote:


 "Mn" <mn mailinator.com> wrote in message 
 news:er492f$1sti$1 digitalmars.com...

 Hello World!

 Is it possible to write a library in D that can be used by other 
 programming languages? And if yes, how to do it? I can think of two ways 
 of "using" a lib in general:

 1. The OOP way: use a class of the lib, then its functions, dunno how its 
 called.
 2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

 I am only interested in the more popular languages like C, C++, Java, C#, 
 PHP.

 Greetings and thank you.
 -- Mn



 No other languages understand D calling or mangling conventions, but D can 
 make functions with C, Windows, and Pascal calling conventions.  If you just 
 do something like:
 
 extern(C) export void func(int x) { ... }
 
 You can then, maybe, make a DLL or something out of it which can be called 
 from virtually any other mainstream language, since most things understand 
 the C calling convention. 
 
 



Thanks for your reply.

But if I now want - for example - to have three functions:

openSomething(...) { connection c = pointer to an opened file }
doSomething(...) { do something with c }
closeSomething(...) { close connection c }

How do I pass the c between these three functions? How do I ensure that c stays
alive until I call closeSomething(...), and then how do I remove it?

Next problem (?) is that it has to be possible to call openSomething multiple
times, use doSomething with the right c multiple times and then close all the
c. Sure i can just return a pointer from openSomething and pass it over to
doSomething and closeSomething - but to what shall this pointer point? And
where to store that? I need something persistant in the lib. How to do this?

Thanks for your help.
-- Mn
Feb 16 2007
prev sibling next sibling parent reply David Gileadi <foo bar.com> writes:
Jarrett Billingsley wrote:

 "Mn" <mn mailinator.com> wrote in message 
 news:er492f$1sti$1 digitalmars.com...

 Hello World!

 Is it possible to write a library in D that can be used by other 
 programming languages? And if yes, how to do it? I can think of two ways 
 of "using" a lib in general:

 1. The OOP way: use a class of the lib, then its functions, dunno how its 
 called.
 2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

 I am only interested in the more popular languages like C, C++, Java, C#, 
 PHP.

 Greetings and thank you.
 -- Mn



 No other languages understand D calling or mangling conventions, but D can 
 make functions with C, Windows, and Pascal calling conventions.  If you just 
 do something like:
 
 extern(C) export void func(int x) { ... }
 
 You can then, maybe, make a DLL or something out of it which can be called 
 from virtually any other mainstream language, since most things understand 
 the C calling convention. 
 



I tried this very thing about a year ago, creating a DLL in D with 
extern(C) functions which was imported and called by a C# program.  It 
passed data back and forth via simple structs, defined on both the C# 
and D side.  It worked great when called via a D host, but would 
segfault every time I tried it from the C# host.  I never did figure out 
what was going on (and since it was a school project I just gave up and 
ported the code to C#).  I suspected it was the fault of the garbage 
collector running in a separate thread, and at the time the calls to 
disable/enable the GC didn't do anything, so I didn't get to test if my 
suspicion was true.

I'd be very interested to hear of your success with this.
Feb 16 2007
parent reply Mn <mn mailinator.com> writes:
David Gileadi Wrote:


 Jarrett Billingsley wrote:

 "Mn" <mn mailinator.com> wrote in message 
 news:er492f$1sti$1 digitalmars.com...

 Hello World!

 Is it possible to write a library in D that can be used by other 
 programming languages? And if yes, how to do it? I can think of two ways 
 of "using" a lib in general:

 1. The OOP way: use a class of the lib, then its functions, dunno how its 
 called.
 2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

 I am only interested in the more popular languages like C, C++, Java, C#, 
 PHP.

 Greetings and thank you.
 -- Mn



 No other languages understand D calling or mangling conventions, but D can 
 make functions with C, Windows, and Pascal calling conventions.  If you just 
 do something like:
 
 extern(C) export void func(int x) { ... }
 
 You can then, maybe, make a DLL or something out of it which can be called 
 from virtually any other mainstream language, since most things understand 
 the C calling convention. 
 



 I tried this very thing about a year ago, creating a DLL in D with 
 extern(C) functions which was imported and called by a C# program.  It 
 passed data back and forth via simple structs, defined on both the C# 
 and D side.  It worked great when called via a D host, but would 
 segfault every time I tried it from the C# host.  I never did figure out 
 what was going on (and since it was a school project I just gave up and 
 ported the code to C#).  I suspected it was the fault of the garbage 
 collector running in a separate thread, and at the time the calls to 
 disable/enable the GC didn't do anything, so I didn't get to test if my 
 suspicion was true.
 
 I'd be very interested to hear of your success with this.



You said you wrote a DLL in D and tried to access it via C#, ok. But what do
you mean with "D host" and "C# host" then?? Accessing a .NET Assembly is
unlikely to be possible that easy from D, although C# offers COM support. I
will post a seperate reply for this topic.

As far as I know there is a way to disable GC for parts of or the whole program.

I will of course continue to look into this, but as of now I just started with
D. Although it looks wonderful and its steep learning curve should be conquered
in zero time.
Feb 16 2007
parent David Gileadi <foo bar.com> writes:
Mn wrote:

 David Gileadi Wrote:
 

 Jarrett Billingsley wrote:

 "Mn" <mn mailinator.com> wrote in message 
 news:er492f$1sti$1 digitalmars.com...

 Hello World!

 Is it possible to write a library in D that can be used by other 
 programming languages? And if yes, how to do it? I can think of two ways 
 of "using" a lib in general:

 1. The OOP way: use a class of the lib, then its functions, dunno how its 
 called.
 2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

 I am only interested in the more popular languages like C, C++, Java, C#, 
 PHP.

 Greetings and thank you.
 -- Mn



 make functions with C, Windows, and Pascal calling conventions.  If you just 
 do something like:

 extern(C) export void func(int x) { ... }

 You can then, maybe, make a DLL or something out of it which can be called 
 from virtually any other mainstream language, since most things understand 
 the C calling convention. 



 extern(C) functions which was imported and called by a C# program.  It 
 passed data back and forth via simple structs, defined on both the C# 
 and D side.  It worked great when called via a D host, but would 
 segfault every time I tried it from the C# host.  I never did figure out 
 what was going on (and since it was a school project I just gave up and 
 ported the code to C#).  I suspected it was the fault of the garbage 
 collector running in a separate thread, and at the time the calls to 
 disable/enable the GC didn't do anything, so I didn't get to test if my 
 suspicion was true.

 I'd be very interested to hear of your success with this.



 You said you wrote a DLL in D and tried to access it via C#, ok. But what do
you mean with "D host" and "C# host" then?? Accessing a .NET Assembly is
unlikely to be possible that easy from D, although C# offers COM support. I
will post a seperate reply for this topic.
 
 As far as I know there is a way to disable GC for parts of or the whole
program.
 
 I will of course continue to look into this, but as of now I just started with
D. Although it looks wonderful and its steep learning curve should be conquered
in zero time.



Maybe "host" wasn't the best choice of words.  I meant the .exe which 
loads the DLL and calls the code--i.e. in this case the C# program was 
the "host".  I also had a program written in D to call the code in the 
DLL.  I never tried to load a DLL written in C# from D code--as you say, 
this is not likely possible, at least not without some massive effort.
Feb 16 2007
prev sibling parent reply Mn <mn mailinator.com> writes:
Jarrett Billingsley Wrote:


 "Mn" <mn mailinator.com> wrote in message 
 news:er492f$1sti$1 digitalmars.com...

 Hello World!

 Is it possible to write a library in D that can be used by other 
 programming languages? And if yes, how to do it? I can think of two ways 
 of "using" a lib in general:

 1. The OOP way: use a class of the lib, then its functions, dunno how its 
 called.
 2. The Un-OOP way: use a function of a lib, its called P/Invoke in C#.

 I am only interested in the more popular languages like C, C++, Java, C#, 
 PHP.

 Greetings and thank you.
 -- Mn



 No other languages understand D calling or mangling conventions, but D can 
 make functions with C, Windows, and Pascal calling conventions.  If you just 
 do something like:
 
 extern(C) export void func(int x) { ... }
 
 You can then, maybe, make a DLL or something out of it which can be called 
 from virtually any other mainstream language, since most things understand 
 the C calling convention. 
 
 



Is it possible to use the COM with D?
Feb 16 2007
next sibling parent BCS <BCS pathlink.com> writes:
Mn wrote:

 
 
 Is it possible to use the COM with D?



http://www.digitalmars.com/d/interface.html

at the bottom
Feb 16 2007
prev sibling parent Frits van Bommel <fvbommel REMwOVExCAPSs.nl> writes:
Mn wrote:

 Is it possible to use the COM with D?



Yes. The last section of http://www.digitalmars.com/d/interface.html :
---
COM Interfaces

A variant on interfaces is the COM interface. A COM interface is 
designed to map directly onto a Windows COM object. Any COM object can 
be represented by a COM interface, and any D object with a COM interface 
can be used by external COM clients.

A COM interface is defined as one that derives from the interface 
std.c.windows.com.IUnknown. A COM interface differs from a regular D 
interface in that:

     * It derives from the interface std.c.windows.com.IUnknown.
     * It cannot be the argument of a DeleteExpression.
     * References cannot be upcast to the enclosing class object, nor 
can they be downcast to a derived interface. To accomplish this, an 
appropriate QueryInterface() would have to be implemented for that 
interface in standard COM fashion.
---
Feb 16 2007