[co_dh]

In q/kdb, bracket for unary function application is optional, that is, f[x] is the same as f x. I found it very convenient after a while, and wish other language follows. It is very convenient to write f g h x, than f[g[h[x]]]

[int_19h]

This is the usual arrangement in functional programming languages - ML, Haskell etc all use juxtaposition to denote function application.

If you want something along these lines, but a bit closer to mainstream, with easy access to popular libraries etc, that would probably be F#.