Lambda the Ultimate

The term "spark" in FP seems to be well established to describe the action of creating a new parallel thread. My intention (and yours?) was to refer to a fairly short lived thread which may not need cell level garbage collection. I haven't done enough research to see if this has prior meaning.

re. OS X, no is probably the short accurate answer. I do intend to pursue the open source route at some point. For now what is holding me back is the potential for embarrassment; there are just too many aspects of the current design and implementation which expose my mathematical and programming limitations!

As for spark lifetimes, there is fairly standard custom allocator for cells etc. This keeps track of blocks allocated from the O/S during spark execution. When finished, they can be freed up very quickly.

If you can run the Windows version, the Store Info button provides details of data store memory allocation; using the same allocator.

It probably comes down to the sort of applications that an Ivory system might address. It has been deployed successfully in an communications gateway similar to an SMS host. Whilst it would probably not be suitable for a high speed IP router, it is very easy to specify script level criteria for routing/interface decisions. For the gateway, sparks are mostly triggered by timers and the presence of socket and serial port I/O.

I'd encourage you to open source it, but be the tzar when it comes to the whole project - people can contribute, but you should keep driving the integration and vision.

Believe me, no matter what your system looks like internally, there are more open source systems that are worse! Would it not be an opportunity to get to work with like-minded folks to trade ideas and learn from one another? And if someone is a jerk, kick 'em off :-)

There is the rush to clean everything up first.

Thanks for the encouragement to go open source, I essentially agree. Does anyone have any recommendations about the best route for this?

What it comes down to is the old simple question: Would anyone want to program in this way?
If not, it becomes a pointless exercise!

I know that the web site is weak - one advantage of open source is that someone might offer to document it properly - but I would still appreciate opinions from this site. So far, most effort has probably gone into the Introduction (updated after raould's earlier comments) and Examples sections.

Finally, believe me, I never intended all this. It just grew. Should it have been killed at birth (around about 1992)?

I intend to do this soon - it is just a question of when I can find the time to bring the Linux version up to date. I agree that it is important to be as O/S independent as possible.

The Linux version is a bit more restrictive in that it currently has no GUI, but it should run the demo scripts. I may decide to wait until putting in place a planned DHTML version with a server side page object model (naturally) and Live connect for the user interface.

A Linux version can now be downloaded from the web site.

It is a bit more restrictive in that it has no GUI. However, scripts may be configured to support remote evaluation, and I have provided some examples. This can be accessed via telnet on port 2152, but it is easy to use any other port.

Through this interface, there is support for single line scripts such as:

"Hello, world"
"This string" = "This" ++ " string"
(atan 1.0) * (360.0 / (2.0 * 3.14159))

Probably more useful are data store queries. The following one rather incestuously returns the name of a connecting host:

(getAt (.commsStore.scriptListenerSocket.connections) 0).peerName

or to shut an ivory session down:

exit 0

Scripts extending over multiple lines may be entered by bracketing them with :{ and :}

:{ (\!n ->
   let !fact2 !acc !n =
      if n = 0 then acc
               else fact2 (acc * n) (n - 1)::Int
   in
      fact2 1 n) 5 :}

For the observant, the Int type constraint is needed because if alternatives are not required to be the same type.

The documentation is still very limited, but I have included an informal explanation - mainly concentrating on one of the example scripts.

I would still welcome feedback as to whether this project is worth pursuing further.

Perhaps aim for more people to see it so that the 1% of viewers that actually try it out becomes a larger absolute quantity? Try bunging it up on Sourceforge, and post on Freshmeat (and maybe even /., shudder) and see what happens :-)

I was wondering those "!" is those for introducing new variables? Because in my language thats what "!" mean, and it looks similar to yours.

Sorry, more and improved documentation will come. For some unknown reason, patterns were omitted from the HTML syntax.

! has two syntactic forms in IvoryScript:

• To signify a strict (or evaluated) variable as per Haskell etc.;
• To force evaluation of an expression where its context is lazy.

The implementation of recursive let definitions is incomplete, but !fact2 declared to be strict currently makes it easier for the compiler to perform the now standard tricks of generating code similar to that from a procedural language; the Linux version on the web site lists the byte code of submitted expressions to show this.