I am learning JavaScript (via Eloquent JavaScript) and thought I would learn Websharper at the same time.
Is there access to JavaScript's prompt command outside of ExtJS?
I searched online and couldn't find anything in the documentation that didn't require a license.
It is indeed missing in the WebSharper API. I filed a bug report and we should add it soon. In the meantime, you can define it as follows:
[Edit: added types for the arguments]