Hi there,

I'm considering pascal scripting engines in stead of hot-swaped compiled stored objects/dlls for server back-end development for clients (namely WebSocket/JS). I came across a few relatively recent solutions and wanted to know if there are any obscure "light weight" scripting engines but yet leverage byte code. My largest problem would be security though. I would want to limit script engine access to OS level calls. I need to be able to "sandbox" these back-end apps so they don't interfere with the server process.

Any thoughts/recommendations? Thanks.

I once wrote a script engine that generated bytecodes.

At the time it was harder due to defective variants support (something like that).

Now it would be easier.

2010/12/10 Andrew Brunner :

I think FPC in general could benefit from a native FPC script. They have a link to a port of REM objects but the website said it was with flaws and tests were needed under linux.

A light-weight scripting engine would need to be restricted to methods and object code. And perhaps some level of access to the networking engine each script would be called from.

IMO, the scripting engine would either be completely thread safe or would have to have multiple instances one per thread.

Do you still have your code? I wonder if the FPC memory manager could handle such an engine running over and over again without losing memory.

On Fri, Dec 10, 2010 at 1:27 PM, Jorge Aldo G. de F. Junior <

RemObject's PascalScript and FastScript both work with FPC.

RemObject's is free to use IRRC.

A while back I wrote a scripting language based on Pascal that features byte code generation. I haven't worked on it in many years though.

http://www.eternallines.com/blaise/
<http://www.eternallines.com/blaise/>

There is also the lysee language. See http://code.google.com/p/lysee/

"Lysee is a small, fast, reliable and cross platform script language. It can be embedded into Pascal programs as a critical mission controler, or to be embedded into HTML to develop active WEB sites."

Marcos Douglas

Some time ago I have converted Delphi Web Script (see http://sourceforge.net/projects/dws/ ). Don't let the name fool you though. It's a normal scripting engine and I'm successfully running it on i386-win32, i386-linux and x86_64-linux. I've also tested a simple script on arm-wince.

But DWS hasn't been updated since quite some time and recently someone else has started a fork of it with focus on Delphi 2009+ compatibility. I'm currently trying to compile this new variant with FPC, but the author has decided to use many Delphi 2009+ features like extended records (luckily the author isn't using variant parts, so I can use objects), extended RTTI (although that is concentrated in one unit), generics (solveable with some ifdefs) and nested types (I'll have to test trunk here, because 2.4.2 has problems with Delphi's syntax).

A link to the author's blog is here: http://delphitools.info/dwscript/ I'd suggest you to read through his DWS related blog entries ( http://delphitools.info/tag/dws/ ) as they contain some interesting performance information as well - which might not be valid for the old DWS though.

Regards,
Sven

RemObjects' PascalScript for me. Definitely what I want. Small, bytecode compiled, cross-platform (to some limits due to the use of assembler), no built-in function (for your security needs), easy registration of functions and classes, has unit importer, and something you won't have in any other scripting language: it's STRONGLY AND STATICALLY TYPED!

Blaise also offers strongly and statically typed variables. In fact, Blaise allows both statically and dynamically types variables.

You can also have a look to BESEN http://besen.sourceforge.net/ which is a full ECMAscript 5th Edition (a ka JavaScript) standard compliant scripting engine, which is developed by me. It has even a JIT for x86 & x64.