CODEWITHSUNDEEP
multithreadingprogramming-languagesvm-implementation
ts.
ts.

Reputation: 10709

searching good embedded & hosting language pair

I am searching for two (one?) languages. One of them would be a host, capable running some "environment", and second, which could used to script "agents" acting in this environment.

Some details:

  1. host should be capable to run multiple "agents" (threads of embedded language), ideally capable to limit number of instructions executed by every thread at a time (though more sophisticated ways of control are welcome)

  2. embedded threads should have access only to objects explicitly exposed by host

  3. embedded threads should be isolated. No shared memory, all communication going via host

  4. embedded language should be rather simple, with dynamic typing

  5. hosting language should be rather high-level

  6. performance is not a primary concern

I was thinking of Python being a host embedding Lua, for example Lunatic Python, or some pair of JVM languages (Scala / Groovy ?), but i'am not sure of possibilities of real isolation of embedded threads (see 2, 3). So I am searching for any ideas, frameworks, successfull implementations etc...

Upvotes: 3

Views: 257

Answers (5)

ng.
ng.

Reputation: 7189

A good example here is SnapScript it can be run on any Java compatible environment. In addition to the standard JRE it can also be run on Android (Dalvik and ART) without any modifications.

The IDE actually manages an agent pool for hot execution.

Upvotes: 0

UNIT POINT
UNIT POINT

Reputation: 31

I know this question is a couple of years old now, but I'd recommend ObjectScript language.

ObjectScript, OS for short, is a new programming language. It's free, cross-platform, lightweight, embeddable and open-source. It combines the benefits of multiple languages, including: JavaScript, Lua, Ruby, Python and PHP. OS features the syntax of Javascripts, the "multiple results" feature from lua, syntactic shugar from Ruby as well as magic methods from PHP and Ruby - and even more!

Upvotes: 0

Miguel Grinberg
Miguel Grinberg

Reputation: 67479

I think the conditions that you have listed aren't very restrictive, you are going to find a large list of pairs of host/thread scripting languages that fall within your six requirements.

So my most important recommendation is that you choose the languages that the intended users will like the most.

There are a couple of ways to approach this. If you decide to start picking a host language, then I think you have the following options:

C/C++: If your intention is to have more freedom of choice for the thread language, then having a C or C++ host will give you the most options, since most interpreted scripting languages are written in C/C++ and have easy mechanisms for embedding into C/C++ applications. Choices for thread languages could be Lua, Javascript, Python, Ruby, PHP, Basic, Scheme, Pascal, Lisp, and many many more.

Java: With Java as a host language you have a short number of scripting languages that are embed friendly. Here is a list.

.NET: I would only go with this if you intend to run on Windows and nothing else, if not I would avoid it. Like Java, you'll find a list of interpreters that can be embedded in a .NET application.

Something else: If you don't like C/C++ or Java as a host language, then you'll have to decide what kind of host language you like, but no matter the choice, you will have a very limited set of options for an embedded language. You suggested Python as a possible host language, which I think is a decent choice. I would advise against using Lua over Python though, that could be a debugging nightmare should you ever need to debug at the language VM level. Instead, I can offer two suggestions: (1) also use Python for the thread language, then you have a nice uniform language across the entire system; (2) find a scripting language that has a native interpreter written in Python (there aren't many that I know of). Instead of Python, you can go with Ruby, PHP, or any other major scripting language for the host, but in all cases you'll have not many options for the embedded language.

Now, instead of looking for a host language, you could pick the embedded language first, then find a host language that can embed that language. You suggested Lua as an embedded language, which is also a very good option. If you are set on using Lua, then I think C or C++ should be your host language, as that will give you the best embedding experience.

To summarize, I recommend one of two following approaches to choosing your pair of languages:

(a) pick a pair of languages where the embedded language interpreter is implemented in the host language. Examples: Lua and C++, Javascript and C++, Python and C++, Scheme and C++, Jython and Java, JRuby and Java, Rhino and Java, etc.

or

(b) pick the same high level scripting language for host and threads, and work on an unified platform without embedded scripting. Examples: Python and Python, Lua and Lua, Ruby and Ruby, etc.

Good luck with your search!

Upvotes: 4

sbridges
sbridges

Reputation: 25140

Using javascript/v8 as the embedded language, and c++ as the host language might be a good solution. See this for how to embed.

V8 provides Contexts, each of which has its own Security Context. These allow you to create multiple separate threads for different clients, each of which is in their own sandbox.

Another alternative is java/javascript(rhino) which also allows embedding. Limiting access to other objects will be harder in java (you have to use a security manager), but you can limit the time a script is allowed to take, see an example in the javadocs here.

Upvotes: 1

Basile Starynkevitch
Basile Starynkevitch

Reputation: 1

You could also use Common Lisp in particular thru its SBCL implementation.

Upvotes: 1

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