[Gardeners] * in Lisp

[Matthew Astley]

I'm interested in the modes of attachment between languages, and how
to help folks find their way around.

  Pipes or sockets.  (LTk; Ajax, Dojo and JSON)

  Embed one in another.  (tcl and guile were designed for it; Python
  can do it; Perl has been linked into Exim and Apache; inline
  assembler in C source is another flavour)

  With the magic of eval you can turn this inside out.  (/usr/bin/cpr)

  Target another language's runtime.  (Parenscript = Javascript in
  sexprs; Kawa & JScheme = Scheme for the JVM; Jython)

  Steal source from another language.  (awk2perl, sed2perl,
  http://www.cliki.net/Zeta-C ...?)


I'm most interested in

  How to do <foo> in Lisp, where <foo> is defined in other language.

e.g. How do I write a heredoc in Lisp?

It has been variously suggested (on cliki) that I don't need to, could
do it easily, or might find it rather tricky.  I haven't tried yet,
but would appreciate advice on where (not) to start.


This is a comparison of language idioms.  Discussion can lay bare one
language's kludge that gets around a shortcoming another language
doesn't have.  Hacking can import those other things that are actually
really neat.

Of course there will be some overlap - maybe I like the kludges enough
to implement them elsewhere.


(this is not a top post)
On Wed, Feb 01, 2006 at 10:32:38AM -0500, Stuart Sierra wrote:

> So far that's Python, Perl, TCL, Prolog, and R.

I was pondering TeX too, but that's not my project.

> Makes me wonder: would it be possible to define a generic interface
> to external scripting languages?

STDIN and STDOUT are easy to get going for question/answer sessions,
provided the victim language has something resembling a REPL.

Perl's Inline modules allow subroutines to be written in many
languages, I guess there's a generic interface in there.  There's also
SWIG which seems to have hooks into pretty much everything.

> That could make CL the ultimate "glue" language, able to use almost
> any combination of libraries from different languages.

Perl used to be the ultimate glue language, and tcl before that?  But
languages seem to be coming together now.

I think people just use whatever language(s) look suitable for the
task.  Start from <here>, pick a destination and fill in the space
with some code.  Some routes are scary, others are well travelled.


More examples,

 - VBA embedded in Excel, linking out to a DLL, if you must
 - [I'm obliged to plug] Python plus TeX, http://www.pytex.org/

...it's a big topic.  Which bits should we garden?


Matthew  #8-)