Microsoft
MicrosoftThese are all great questions! Here are a few quick answers.
1. I didn't had a chance to test it yet but are lambdas first-class citizens, e.g can i pass a function as a function argument?
Yes, these are indeed first-class citizens and in fact all new data types. These make use of the tech behind data types and mean that lambdas are indeed values that can be passed around. It wouldn't be fair to call this a lambda if it wasn't a function as a value!! To reiterate, just like we introduced new data types (geo, stocks, the wolfram entities, power bi types, power query types...), lambdas can be thought of as another type of value calc is aware of and can be passed around like anything else. I think this is pretty cool because it means we can unleash even more powerful use-cases for lambdas in the future. The limitation with returning them in the grid was one we had to introduce due to some challenges with formula adjust.
2. Why LAMBDA formula has been introduced instead of using ()? I'm sure you've think of it but wondering what was the obstacles prevented it.
Another great question! We introduced this as a formula because it makes our lives a bit easier when it comes to backwards compatibility. Functions are more resilient when parsing and evaluating them in different versions.
2. Excel formula languages is increasingly moving towards a fully fledged functional programming language with LET() and LAMBDA(). But tools which are available to "real" developers (IDE, code analysis tools, etc) are simply non-existing in the Excel world.
For instance LET() function was shipped without ability to debug names with F9 key...
Do you have plans in foreseeable future to bring those features? Formula formatting, debugging (at least with F9), code navigation (jump to function definition, etc) and so on.
I completely hear you on this one! I can't share more about what we are doing in the future but I will say that I definitely share your sentiment. I would love to see us add much needed tools for debugging and authoring formulas. Akin to what you get with great IDEs.