Linking languages

Question

I asked a question earlier about which language to use for an AI prototype. The consensus seemed to be that if I want it to be fast, I need to use a language like Java or C+

Answer 1

First, a meta comment: I would highly recommend coding the entire thing in a high-level language, profiling like mad, and optimizing only where profiling shows it's necessary. First optimize the algorithm, then the code, then think about bringing in the heavy iron. Having an optimum algorithm and clean code will make things much easier when/if you need to reimplement in a lower-level language.

Speaking for Python, IronPython/C# is probably the easiest optimization path.

CPython with C++ is doable, but I find C a lot easier to handle (but not all that easy, being C). Two tools that ease this are cython/pyrex (for C) and shedskin (for C++). These compile Python into C/C++, and from there you can access C/C++ libraries without too much ado.

I've never used jython, but I hear that the jython/Java optimization path isn't all that bad.

Answer 2

If you choose Perl there are plenty of resources for interfacing other languages.

Inline::C
Inline::CPP
Inline::Java

From Inline::C-Cookbook:

use Inline C => <<'END_C';

  void greet() {
    printf("Hello, world\n");
  }
END_C

greet;

---

With Perl 6 it gets even easier to import subroutine from native library code using NativeCall.

use v6.c;

sub c-print ( Str() $s ){
  use NativeCall;

  # restrict the function to inside of this subroutine because printf is
  # vararg based, and we only handle '%s' based inputs here

  # it should be possible to handle more but it requires generating
  # a Signature object based on the format string and then do a
  # nativecast with that Signature, and a pointer to printf

  sub printf ( str, str --> int32 ) is native('libc:6') {}

  printf '%s', $s
}

c-print 'Hello World';

This is just a simple example, you can create a class that has a representation of a Pointer, and have some of the methods be C code from the library you are using. ( only works if the first argument of the C code is the pointer, otherwise you would have to wrap it )

If you need the Perl 6 subroutine/method name to be different you can use the is symbol trait modifier.

There are also Inline modules for Perl 6 as well.

Answer 3

I agree with the Idea of coding first in a high level language such as Python, Profiling and then Implementing any code that needs speeding up in C / C++ and wrapping it for use in the high level language.

As an alternative to boost I would like to suggest SWIG for creating Python callable code from C. Its reasonably painless to use, and will compile callable modules for a wide range of languages. (Python, Ruby, Java, Lua. to name a few) from C code.

The wrapping process is semi automated, so there is no need to add new functions to the base C code, making a smoother work flow.