Support immediate invocation of a function

[barmac]

Is your feature request related to a problem? Please describe.

The expression below fails to parse even though it's correct FEEL

(function(a) a)(3)

Error reported in the FEEL Playground:

failed to parse expression '(function(a) a)(3)': Expected (binaryComparison | between | instanceOf | in | "and" | "or" | end-of-input):1:16, found "(3)"

Describe the solution you'd like

Parse and evaluate correctly as in nikku/feelin: https://nikku.github.io/feel-playground/?e=%28function%28a%29+a%29%283%29&c=%7B%7D&t=expression&st=true

Related issues

• Camunda Autormation Platform 7:
• Zeebe broker:

[saig0]

@barmac thank you for reporting. 👍 This is an interesting case. 😅

Do you have any concrete use case?

[barmac]

I discovered this when I tried to explain how boxed function definition works on concrete data. It's not a blocker for anything right now, so I'd give it low priority.