Example of executing via embedded library?

[tigerinus]

This project looks interesting.

Is there an example of running a .tm from within a custom Golang code?

Thanks.

[myzie]

Hi @tigerinus, thanks for dropping by. Here are a couple examples that are relevant, although please let me know if this doesn't fully answer your question.

1. https://github.com/cloudcmds/tamarin/blob/main/cmd/simple-example/main.go
2. https://github.com/cloudcmds/tamarin/blob/main/tamarin.go#L70-L85

The first link there is meant to look very similar to what you would need to do in your own Go program.

[tigerinus]

Yeah, that built-in function mechanism is helpful.

Can we go extra mile by making it (semi-) runtime based call, versus hard coded in built-in function?

I don't mind a go:generate approach to pre-scan the .go file with interface structs in it, and pre-populate build-in functions based on the scan.

[myzie]

That is a fun and interesting idea to use go:generate to help with this. I think it would help make this concrete if you could share an example of an interface you'd want to expose to the Tamarin code.

I'm guessing you want the interface to deal with native Go types, rather than Tamarin object types? But I want to check on that.

As in, you want your interface signatures to be something other than this, the built-in function signature:

type BuiltinFunction func(ctx context.Context, args ...Object) Object

(from https://github.com/cloudcmds/tamarin/blob/main/object/builtin.go#L9)

[tigerinus]

Here is a concrete example from my project:

https://github.com/IceWhaleTech/CasaOS/blob/main/service/notify.go

It'd be beautiful to allow my developers to script certain functionalities against the NotifyServer interface, load and run them on the fly. That greatly reduces the development cost for 3rd party contributors. It also makes the idea of script based extensions possible.

[myzie]

Perfect, thanks for this example. Transforming the input and output types seems like the most difficult aspect of this, and it seems like we could get it to work in a lot of situations. I'll look into this.

[myzie]

@tigerinus - check out the changes in v0.0.9. Here is an example of proxying to a Go service. This may work for your NotifyServer use case, if you register the handful of types you have with a Tamarin ProxyManager.

[andrewkroh]

I was looking over the examples. I think it would be useful to be able to parse once and then reuse the returned ast.Program with repeated evaluations. It looks like that's not quite possible for external users because the parser is in internal/? I am thinking of a similar use case as @tigerinus where the script is an extension point in an app, and you load it once and then execute it repeatedly upon some event to customize behavior.

[myzie]

Yeah. It looks like if I pull the internal/parser package out of internal then that would be supported. I'll make this update soon.

[myzie]

Hi @andrewkroh - I made these updates. Here is an example of reusing an already parsed AST:
https://github.com/cloudcmds/tamarin/blob/main/cmd/example-ast-reuse/main.go

[andrewkroh]

Thanks! I'll try that out.