Does Hy add its own "symbol" datatype, or use something in the standard library?

Own symbol type

    => 'foo
    HySymbol(u'foo')

Assignment and conditionals are expressions, however assignment returns None.

    => (setv bar (setv foo (if True True False)))
    => (type bar)
    <type 'NoneType'>

Quoted expressions evaluate to Hy AST.

    => '(+ 1 2 3)
    HyExpression([
        HySymbol(u'+'),
        HyInteger(1L),
        HyInteger(2L),
        HyInteger(3L)]
    )

So it's kind of a frontend for the Python compiler, it goes:

Hy AST -> Python AST -> Python bytecode

Users of Hy who don't know Lisp deserve to be informed that in an actual Lisp, it goes more like this:

  => 'foo
  foo

(or, at worst FOO rather than foo).

  => '(+ 1 2 3)
  (1 2 3)