Why can't ruby just compile to erlang's VM?

[benwilson512]

I think Robert’s post generally settles this issue. If @sztosz or @Nobbz have further questions, then they’re free to ask them.

[OvermindDL1]

@rvirding

As others have mentioned you can’t directly compile Ruby down to the BEAM (erlang VM) as the underlying semantics are very different and quite incompatible, and the BEAM very specifically targets Erlang semantics. It’s Erlang all the way down.

Entirely, I came from erlang to Elixir instead of from Ruby as many here did, it is entirely erlang, just with a nice macro interface on top and a more verbose syntax. ^.^

@rvirding

What you could do however, is implement Ruby in Erlang. I have done it for Lua; it’s called luerl, and is complete implementation of Lua 5.2. Seeing we have to implement Lua’s global, shared, mutable data in Erlang it is slower than a native implementation but the interface between the languages is very fast. And you get all of Erlang’s concurrency and system building for free. You could run millions of connections implemented in Ruby on one machine.

I’ve actually been thinking of integrating luerl into a home project here soon for a client-scripting capability on the server. I need to look in to how well sandboxed and such it is. ^.^

Any thoughts on a Lua 5.3.3 update? ^.^

[rvirding]

@OvermindDL1

I’ve actually been thinking of integrating luerl into a home project here soon for a client-scripting capability on the server. I need to look in to how well sandboxed and such it is. ^.^

Any thoughts on a Lua 5.3.3 update? ^.^

Sandboxing is no problem. To get “outside” the Lua you need to implement modules in erlang which are called from Lua and then call erlang. There is no way to load these modules from inside Lua so it is safe. All you need to do is to remove the “dangerous” built in module, which are implemented in this way, and then you are safe. To be really safe you could monitor the Lua processes and check for run-time and process size.

Updating to Lua 5.3 completely depends on my time and user demands.

[OvermindDL1]

@rvirding

Sandboxing is no problem. To get “outside” the Lua you need to implement modules in erlang which are called from Lua and then call erlang. There is no way to load these modules from inside Lua so it is safe. All you need to do is to remove the “dangerous” built in module, which are implemented in this way, and then you are safe. To be really safe you could monitor the Lua processes and check for run-time and process size.

That is entirely what I wanted, perfect.
And I’d probably want to watch the run-time and sizes too considering user-ran, can figure it out if the instrumentation and hooks are there.

@rvirding

Updating to Lua 5.3 completely depends on my time and user demands.

Hehe, well one demand here but it is not a biggy, 5.3 just has a few bits that would be useful for what I’m making but certainly not a stopper by any means.

[OvermindDL1]

Also, as for ruby, there is a ruby vm on erlang too: https://github.com/johnlinvc/erruby

It is partly functional. ^.^