Represent and run a minion model in Rust

[niklasdewally]

I have a model running in Minion from a rust representation.

There are example problems for both the low level bindings and the Minion Rust AST versions inside raw_bindings.rs and run.rs respectively.

The work is very incomplete, things I still need to do (that I know about) are:

• How to deal with boolean / non int constants
• Memory management / freeing C++ stuff
• I assume that variables used in the ast are defined in the symbol table, and if they aren't this could segfault.
• Return Result instead of panicking
• Callbacks and Solutions
• Style and docs

[niklasdewally]

Feedback would be appreciated @ozgurakgun @ChrisJefferson @lixitrixi @Kieranoski702

(This can wait till Monday, I know I am working unsociable hours this week)

[niklasdewally]

No idea if the CI will work or not - as described in #27 minion is not threadsafe yet, but cargo tests run multithreaded

Tests run on host-server, haven't tested it on mac yet...

No outputs yet for the run.rs version , but there are logfiles that show that minion is doing stuff and getting solutions!

[ChrisJefferson]

is this just a typo?

[ChrisJefferson]

I think this is quite good, and it would be nice to merge, because while lots of things still need doing, it gives us all a base for hacking on, where things run "end to end".

[ChrisJefferson]

To deal specifically with the crashing issue, I'd suggest changing the start of runMinion in libwrapper.cpp to look like this:

std::mutex global_minion_lock;
ReturnCodes runMinion(SearchOptions& options, SearchMethod& args, ProbSpec::CSPInstance& instance, bool(*callback)(void)) {
  std::lock_guard<std::mutex> guard(global_minion_lock);

This just makes a global mutex, and then locks it while in runMinion. This stops multiple calls to runMinion running at once (obviously). C++ is quite good at cleaning up (the mutex should be automatically unlocked when this function exits), so this should create problems even if minion exits with an error.

[ozgurakgun]

or should I? this is still marked as a draft?

[niklasdewally]

or should I? this is still marked as a draft?

As long as you are happy with this still referencing my dev branch of minion, it can be merged.
(I havent quite finished with the C++ side of this)

[niklasdewally]

Might be good to hack over later

[ozgurakgun]

some minor comments

[niklasdewally]

@ozgurakgun I've renamed those things suggested.