Finally bit the bullet and got scripting working in Dynamo-Browse. It’s officially in the tool, at least in the latest development version. It’s finally good to see this feature implemented. I’ve been waffling on this for a while, as the last several posts can attest, and it’s good to see some decisions made.

In the end I went with Tamarin as the scripting language. It was fortunate that the maintainer released version 1.0 just as I was about to merge the scripting feature branch into main. I’ve been trying out the scripting feature at work and so far I’ve been finding it to work pretty well. It helps that the language syntax is quite close to Go, but I also think that the room to hide long-running tasks from the user (i.e. no promises everywhere) dramatically simplifies how scripts are written.

As for the runtime, I decided to have scripts run in a separate go-routine. This means they don’t block the main thread and the user can still interact with the tool. This does mean that the script will need to indicate when a long running process is occurring — which they can do by displaying a message in the status line — but I think this is a good enough tradeoff to avoid having a running script lock-up the app. I still need to add a way for the user to kill long-running scripts (writing a GitHub ticket to do this now).

At the moment, only one script can run at any one time, sort of like how JavaScript in the browser works. This is also intentional, as it will prevent a whole bunch of scripts launching go-routines and slowing down the user experience. I think it will help in not introducing any potential synchronisation issues with parallel running scripts accessing the same memory space. No need to build methods in the API to handle this. Will this mean that script performance will be a problem? Not sure at this stage.

I’m also keeping the API intentionally small at this stage. There are methods to query a DynamoDB table, get access to the result set and the items, and do some basic UI and OS things. I’m hoping it’s small enough to be useful, at least at the start, without overwhelming script authors or locking me into an API design. I hope to add methods to the API over time.

Anyway, good to see this committed to.