Agree about Haskell... as far as I'm aware there is actually no declarative/easily-readable definition of the Haskell syntax that is also complete, especially when it comes to the indentation rules, and the syntax is basically defined by the very (ironically) imperatively-defined GHC parser[0].
I prefer a syntax like in Pure[1], where the ambiguous, hard to parse indentation-based syntax is replaced by explicit semicolons (Yeah, you can use braces/semicolons in Haskell as well, but most code doesn't).
[0] https://github.com/ghc/ghc/blob/master/compiler/GHC/Parser/L...