APL was capable of doing something similar. It would be nice to have keyboards with extended set of characters.
I don't grok this argument, when would one like to have that?
For me personally J is all about tacit functional programming. Any APL have this?
J, to me, took the worst features of APL (the profusion of symbols that only loosely resemble anything else you've ever seen) and makes it even worse, because at least the APL symbols were (usually) visually distinct! From the J examples page are gems like this
var =: ~.@(] , |:&.> , |.&.> , |."1&.>)^:3
which in the proportional font they use makes for a real entertaining time telling , from ,. from .. - +/ p * ^. p
where p is the array. you can even remove the duplication of the array with a so-called hook: - +/ (* ^.) p