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Hi,

We, the cling team, have announced cling, our C++ interpreter prototype! (note: its SVN repository has changed compared with the announcement email; see the build instructions)

To a large extend thanks to Vassil's impressive commitment, cling now behaves like a good C++ interpreter: it runs C++ code that's entered, and prints the results.

[cling]$ #include <cmath>
[cling]$ double x = std::sin(3.1)
(double) 4.158066e-02
[cling]$ .L libz
[cling]$ #include "zlib.h"
[cling]$ zlibVersion()
(const char * const) "1.2.3.4"

$ echo 'extern "C" const char* zlibVersion();
 zlibVersion()' | cling -lz
 
(const char * const) "1.2.3.4"

We have of course already added a few features that we liked from CINT - but cling is a completely new development, based on clang and llvm, a set of compiler libraries (to simplify the matter a bit :-) Vassil will present the innards of cling probably in October; I will post the slides here.

So what's special about cling? It's based on a production-grade compiler and it's designed taking decades of experience with CINT into account. And it doesn't need dictionaries! (Disclaimer: that does not mean that ROOT can do without, automatically. But that's our goal, of course.)

The next steps will be the ones most relevant for High Energy Physics: integration into ROOT (Paul is already working on that) and reloading of changed code (.x myCode.C, edit, .x myCode.C). That latter part is horrible for a compiler.

If you want to check cling out you can simply compile it yourself - it's really easy. I'd love to have an interactive, web-based interface once, but an online C++ interpreter is an invitation for script kiddies to hack the server :-( If you have an idea how to do it please let me know!

Cheers,