I came across a website where you can try out Haskell block-based UI programming. It's really cool! Since Haskell is a declarative language, it seems to be a good fit for this kind of programming. The image shows an example of factorial calculation using fixed point recursion. Although it's not currently running, when I looked at the converted text, it matched the expected code, so it should work. The website is called Blockly for Haskell.
By the way, I found this tweet from @lotz84_ on June 2, 2021: .