It's very much in alpha as there are some known limitations / quirks, but currently it highlights syntax errors, missing dimension errors, incompatible line item / formula data types and allows you to hover over a line item to see it's data type and dimensions. A couple of examples of how it looks below.
Hover to see dimensions:
Highlight data type errors:
Missing dimension warnings:
All the above are far from perfect; some of the error messages could be better but are a very basic first step. I'm also working on being able to hover over more things with data types (list items, list item properties, functions etc, not just line items), as well as things like function names to get the parameters etc.
Context-aware customised auto-complete for lineitem names / functions / module names etc is also on the list.
I'd be very interested in any feedback anyone has.
Possibly the formula editing enhancements it does, yes, although I've got lots of testing / enhancements to do. I've focused on utilizing a better editor engine (the one Anaplan are moving to; Monaco) to be able to provide things only really possible by parsing the formula being edited and integrating with Monaco's extendable functionality.
Thanks for the feedback. I'm currently planning on adding even better missing mappings support where it tries to add them for you with auto-complete based on your existing mappings (i.e. working out you use line items on PROP ... modules typically).
Re. formula formatting, you mean currently you have this on the current formula editor (with A+ I assume), but with the new experience you don't? I read somewhere that formula formatting was something on Anaplan's roadmap, so I've not put that in as a feature of my extension.
FYI The extension now includes the option to format/indent a valid formula; I decided not to wait for Anaplan to put formula formatting/indentation into their editor. Any issues / thoughts for further enhancements please let me know!