Not at all— any feedback is appreciated :)

I'm beginning to have doubts about String mutability. Fortunately the only actually mutating method at the moment is append, which is redundant with add but for the mutability, so I might just tear that out.

Required parentheses on functions are pretty unfortunate. I'm mainly trying to avoid the situation in Ruby where trying to access functions as first-class objects requires all sorts of weird syntactic overhead. Possibly I could have some kind of prefix operator, so (say) &obj.method would return the function object, and obj.method would call it?

I agree about the ':' 'do/end' ugliness. Originally blocks were delimited by braces, but I think the Ruby-style delimiters look nicer. Frankly I'd prefer to get rid of the ':', but for single-expression functions that looks pretty awful. I could do Haskell-style '=' (Haskell of course being where the 'function-body-is-single-expression' thing came from), but

    fn foo(x) = do
      ...
    end

is also pretty weird-looking; kind of like Scala's function definitions, which I find really abrasive for reasons I can't fully explain.

Binding 'self' is also basically a compromise. Originally it was stored in the method, but that required copying each type's methods (and each parents' methods) into an object on instantiation, which was a pretty much unacceptable performance hit. My thinking is that, whenever you'd want to pass a method 'obj.method', it's equally possible to pass 'fn (x): obj.method(x)'.

I need to rework the 'try...catch' statements in any case; their current semantics are incredibly horrible (it wraps, then immediately calls, the try body in a temporary lambda). Maybe I will just incorporate them into blocks— thanks for the idea!